Bulletin 591 December 1957
UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATIONS
J. R. BECKENBACH, Director
(A contribution from the Citrus Experiment Station)
Insects and Mites Found on
JAMES T. GRIFFITHS
W. L. THOMPSON
Mesophyll collapse caused by purple mite infestation. Note the dead
leaves in center which have died in place. Leaves at top have dropped,
leaving bare twigs.
Yellow and red Aschersonia fungus on whitefly.
SCALES AND RELATED INSECTS .............................. --- ...-................ 5
Armored Scales ..........---.. ------------------.--.......-- ...---..... 5
Purple Scale --.......--......-- ... -.......--....--.---............ 6
Florida Red Scale ...-- ------............. --.. .. -----......----- 8
Chaff Scale --............. ...-----...... .........-....- 13
Dictyospermum Scale .......-.....-.. .--.. --......--. ........- -..-- ..... .. 14
Yellow Scale ..........--............. --- -------....-- ...-- ..... 15
Snow Scales .................-...- -----...---..-.........--...... 15
Long or Glover's Scale .................... ..... ........................... 16
Chemical Control of Armored Scales ..........-.................................. 18
Biological Control of Armored Scales ................----................ ....... 20
Unarm ored Scales ...............--........--- ....-......... ..-....-............. .................. 22
Soft Brown Scale ......-- ....-------...---- ......-------.... .............. 23
Black Scale ........--- .....-- ....--..-........ -...--........... 24
Hemispherical Scale -- --...........-................ ................. 25
W ax Scale ..................... ...- .. ... ......----.................... 25
Green Scale ------.....----------.-.............................---------- .... 27
Green Shield and Pyriform Scales .............................................. 28
Control of Soft Scales ............... ----........-......-....... --- 29
Insects Related to Scales ......----......-..-...-- ---.................... ----- 29
Cottony Cushion Scale ....-....................... ...-................ 29
Mealybugs ....--....-- ....------....-..... -------.....................-....- 30
Whiteflies .... ----........... .......-...--- .....----------- ----........................ 33
Cloudy-winged and citrus whitefly ....................-...--.....-.........--. 35
Woolly whitefly .............. ................. ......... -------36
Control of whiteflies --....-....--.......... ------------.............. 39
MITES ------ ---------....................... ----------------...................-- 39
Citrus Rust Mite ..--..---....--..-.--.-....-..-- ----------.......... 39
Control ......-- --......----......... -..................... 42
Spider Mites -----------..........--.......... ................. ---- 43
Purple Mite ....-..... -- .------..................... ................. 43
Six-Spotted Mite ..-- ---............................................. 49
Texas Citrus Mite --...--............ ----------........................- 51
Broad Mite --.........--.... ... ---------..... . ................... .... 52
Control of Spider Mites ..-- ------- -------.. .. .................... 52
False Spider Mites ............- .....----------......--- ........--............ 53
MEDITERRANEAN FRTIT FLY ............---- ...................... ---............. ...... 54
INSECTS OF MINOR IMPORTANCE .-....-...-- --.. ......-..................... 55
Aphids ...........-..... ----... -. .........-. ..... -............--------- 55
Green Citrus Aphid ------ ---........ .........-- -- ..---............ 59
Melon Aphid ..----.............. --. --------. --- ....--......- ............ 59
Black Citrus Aphid ----.-.........--------..... ----.-.......-----.. 59
Control .---....-----.. --.........--..... --...-- -.......--................ 60
Plant Bugs .--..---..-----...----........-----------......................... 60
Control -------.- ----....--..........-------------.--........................ 62
Thrips -..---.........-- ..----- ...---------........- ....................... 63
Termites ......--------.. -..-----..--.-..---............----...... 65
Ants -- .. .........-------------------- --.-.........-- .... .......... 67
Beetles ...---.--------......... ... -------.... ....- -.................. 68
Weevils ....................... ......--- -----------............... 68
Other Beetles ......................................-------.------- ...... -- 72
Grasshoppers and Related Insects ..................------........................... ... 72
American Grasshopper ...................... ....... ................. ..... 72
,Eastern Lubber Grasshopper ........................... .... ................ 73
Control ...............-........ ... .........- ............ ...- ...- 76
K atydids ............................ ............................................................................ 76
Katydids -.---- ..--.^.----....................----------------------------------------*....................... 76
Restless Bush Cricket ...................................... .................. .............. 78
Moths and Butterflies ......................... .................................. 79
Orange-D og .......- ................. ........ .... ........................................ 79
Orange Tortrix -----.................. ... ... .............................. 81
Scavenger Worms ................................. .............................. 83
Leaf M iner ................................................... ........ ............ ....... .. 88
Miscellaneous Lepidoptera ........................ ............................. 83
Psocids ............................. .. .... ....................... ---- -....... ........... 85
Orange Jassid ........................ ......................... .............. ........................ 89
ACKNOWLEDGMENTS ................................................................................. ..... 91
LrrERATUR CITED ................................................................................................ 91
INDEX ...................... .................... .. .... ............................. 94
Insects and Mites Found on
By J. T. GRIFFITHS and W. L. THOMPSON *
The insects and mites which attack citrus in Florida cause
serious economic losses to growers. This publication is meant
to serve as a guide to the citrus grower in the identification of
the cause of injury and to enable him to recognize many of the
insects and mites which are found in groves. Information on
entomogenous fungi and beneficial insects is being accumulated.
A brief discussion of this is included.
It is impossible here to adequately describe all the insects
and mites which may be found in Florida citrus groves. This
bulletin attempts to describe the insects and mites which are
actually injurious; those which are known to be beneficial; and
some of the more obvious species that live on citrus trees, but
whose injury, if any, is not known. Very limited information
is presented concerning methods of control. A spray schedule
is published annually as a part of The Better Fruit Program.'
This contains the most recent detailed information for the con-
trol of citrus pests and should be a major reference source for
those who are planning control programs.
Between 1935 and 1940, a veritable revolution took place in
Florida citrus groves so far as insect and mite injury is con-
cerned. Insects which were formerly of major importance as-
sumed a minor role and others which were not recognized as
pests required regular control measures.
Two species of scale insects and three species of mites are
the major pests of citrus today. Of these, purple scale probably
Dr. Griffiths: Formerly Associate Entomologist, Citrus Experiment
Station, now production manager, Eloise Groves Association, Winter
Haven; Mr. Thompson: Entomologist, Citrus Experiment Station, Lake
1Copies may be obtained from Agencies of the University of Florida;
the Florida Citrus Commission, Lakeland; or insecticide and fertilizer
dealers or manufacturers.
4 Florida Agricultural Experiment Stations
causes the heaviest annual loss to growers by killing wood and
causing fruit to drop. However, the control of rust mites entails
the heaviest expense. Florida red scale, purple mite (citrus
red mite) and six-spotted mite are also major pests in many
groves throughout the citrus area.
Fig. 1.-Three types of hand lens-the linen tester on the left, the
Coddington lower right and Hastings upper right. These are most satis-
factory for grove use if they magnify 10 times.
Numerous other insects and mites are occasionally injurious
in some groves. In certain years they may be of major im-
portance and their injury extremely severe. Additional insects
and mites are regularly found on citrus trees, but their injury,
if any, is minor. They may even be beneficial because some
feed upon or live inside the bodies of harmful citrus insects.
In order for the grower to study his own insect or mite
problems, it is essential that he own and know how to use a
hand lens. Many insects and mites are so tiny that they cannot
be seen with the naked eye. Hand lenses of several types are
available (see Fig. 1) : the linen tester, the Coddington and the
Hastings. Magnifications of 7 or 10 times (7X or 10X) are
usually satisfactory, but some people prefer no more than a
5X magnification. Others prefer a 14X or 20X lens. As mag-
nification increases, the size of the lens field and the depth of
Insects and Mites Found on Florida Citrus 5
focus decrease so that higher magnifications have a limited use
in the field.
SCALES AND RELATED INSECTS
There are numerous scale insects which regularly or oc-
casionally infest citrus. Several are of economic importance,
but others are seldom sufficiently common to be considered as
pests. Scales belong to the order Homoptera. For discussion
purposes they will be divided into four groups: Armored scales,
unarmored scales, cottony cushion scale and mealybugs.
Two major citrus pests, purple scale, Lepidosaphes beckii
(Newm.) and Florida red scale, Chrysomphalus aonidum (L.),
are armored scales. These two species have been thoroughly
discussed in two Florida Experiment Station Bulletins (15, 54).
Therefore, the information presented on these two species will
be brief. In addition to the two major pests, the following
armored scales will be considered: chaff scale, Parlatoria per-
gandii Comst.; dictyospermum scale, Chrysomphalus dictyo-
spermi (Morg.); yellow scale, Aonidiella citrina (Coq.); long
or Glover's scale, Lepidosaphes gloverii (Pack.) ; snow scale,
Unaspis (Chionaspis) citri (Comst.) ; and fern scale,2 Pinnaspis
aspidistrae (Sign.). All of these insects occasionally require
control measures, and they may be of considerable importance
in individual groves.
The armored scales are characterized by a waxy armor which
is secreted by the insect. This is enlarged as the insect grows
to maturity, and is the part usually seen by the citrus grower.
It is actually not the insect itself, but rather a sort of house
under which the insect lives. In order to determine if a scale
insect is alive, it is necessary to turn the armor over and examine
the insect underneath. In some instances (purple scale and
chaff scale are good examples) a membranous sheath also is
secreted underneath the insect so that it is almost entirely en-
closed by a protective covering. Descriptions of scales are
2 Common name suggested by G. B. Merrill,.former entomologist, Flor-
ida State Plant Board.
6 Florida Agricultural Experiment Stations
generally those of the females, since these are most frequently
observed by the grower.
The life history of all these insects is essentially the same.
Usually eggs are laid under the armor. The tiny insect which
hatches from the egg is called a crawler. It has six legs and
moves about freely. It finds a satisfactory place to feed and
there attaches itself to the leaf, twig or fruit by inserting its
mouthparts into the plant. After attachment, the crawler se-
cretes a waxy cover over its upper surface. Throughout this
time the individual is considered to be in the first nymphal stage
or first instar.
The first instar nymph then molts. During this process the
use of the legs is lost, a new outer skin is formed inside the
old one, and as the molt is completed, the old outer skin is
actually incorporated into the armor. Now the armor is com-
posed of two pieces: a waxy outside layer and an under portion
composed of the old nymphal skin. After the first molt the scale
is called a second stage or second instar nymph. It reinserts its
mouthparts and is again attached to the plant.
Following a period of growth, a second molt occurs and
again the old nymphal skin is incorporated into the enlarged
waxy armor. This is the last molt for the female. She increases
in size and enlarges her armor. After fertilization takes place,
she lays eggs.
In the case of the male scale, there are pre-pupal and pupal
stages following the second instar, each of which is followed
by a molt. The adult male scale which has both wings and legs
as an adult, looks somewhat like a tiny gnat. These very fragile
insects are usually not recognized as scales.
Purple scale, Lepidosaphes beckii (Newm.), causes more eco-
nomic damage to citrus trees throughout Florida than any other
one pest. It is present throughout the state and it is a rare
grove where purple scales do not pose a problem at some time
during the year.
The purple scale female lays eggs which hatch in 15 to 20
days in summer. As the eggs are deposited under the armor,
the female's body shrinks in size until she occupies only the
very front part of the armor. After the eggs hatch, the crawlers
move about and settle on leaves, twigs or fruit. They pre-
Insects and Mites Found on Florida Citrus 7
fer places where resi-
due has collected or
along a leaf margin.
The remainder of the
life cycle is typical
of that of armored
scales. Under Flor-
ida conditions three
or more generations
may develop each
year. During the
summer a complete
cycle will take place
in less than three
The scale itself is
pearly white and is
found under an elon-
gate brownish armor.
The crawler which
hatches from a white
egg is also pearly
white but oblong in
shape. After the
crawler settles, it
secretes an armor
which is ridged.
This is visible only
through a hand lens.
As the insect grows,
the armor elongates.
It is brownish for
the female, but in the Fig. 2.-Purple scales, mostly adult females,
case of the male, it on orange leaf. White areas are saprophytic
fungi. (Slightly enlarged.)
is a dark purple. The
male armor is shorter and narrower than that of the female.
Although males tend to settle on the upper side of the leaf and
females on the under side, both sexes may be found together.
Purple scales infest the wood, leaves and fruit. The pres-
ence of large numbers of scales will kill wood and leaves. Even
a few scales around the fruit stem may cause it to drop pre-
maturely. Thus, heavy infestations result in less fruit, dead
8 Florida Agricultural Experiment Stations
wood, larger pruning bills and poorer fruit quality. The major
effect on fruit quality is the retention of green spots on the
fruit where a living scale was present at the time of picking.
If the fruit has not degreened naturally, these spots will remain
green and thus reduce the grade. This can be a very severe
problem on early varieties and is particularly serious when fruit
has to be degreened in the coloring room.
Fig. 3.-Citrus twig and leaves heavily infested with purple scale.
FLORIDA RED SCALE
Florida red scale, Chrysomphalus aonidum (L.), is found on
a multitude of different host plants as well as on citrus. It is
Insects and Mites Found on Florida Citrus 9
------ | mm.
Fig. 4.-Stages in the life cycle of purple scale. A, Early first stage;
B, molting upon completion of first stage; C, early second stage; D, molt-
ing upon completion of second stage; E, early third-stage female; F, im-
mature third-stage female; G, mature third-stage female; H, full-grown
armor of male. a, Area occupied by first-stage armor; b, area occupied
by armor grown during second stage; c, area occupied by armor grown
during third stage. 1, Boundary of first-stage armor; 2, boundary of
10 Florida Agricultural Experiment Stations
a tropical and sub-tropical species that occurs throughout the
Florida citrus area. Infestations of this insect have become
more prevalent in many groves in the Ridge Section of central
Florida, where previously it had been considered to be of little
importance. It is a regular problem in many groves in the
Florida red scale has a round armor. This armor has a
ringed color effect with brown or purple alternating with an
almost reddish color. The armor of the mature female is very
dark purple with a nipple-like center which may be brown.
The male scale produces an apron on one side of its armor. The
central, round portion is dark purple while the apron is more
or less colorless. The actual scale under the armor is lemon-
yellow. The crawlers are the same color and ovoid in shape.
When they first settle and begin to cover themselves with an
armor, the wax is white. This stage is referred to as the "white
Fig. 5.-This severe Florida red scale infestation shows both male and
female armors. The large individuals are the armors of mature females.
The many smaller armors are either second stage females or fully formed
armors of males. Close scrutiny will show the translucent apron on the
side of the armor of some males. (Enlarged.)
Insects and Mites Found on Florida Citrus 11
A B C D E
a 2 2
b3 b-L 3
d d d
S= Imm. I
Fig. 6.-Stages in the life cycle of Florida red scale. A, White-cap
stage; B, early first stage; C, molting upon completion of first stage;
D, early second stage; E, late second stage (this is more typical of male
scale. The armor of the female at this stage is getting lighter colored and
shortly shows a ringed effect) ; F, full-grown armor of male; G, early third
stage with ringed effect which appears during molting process; H, im-
mature third-stage female; I, mature third-stage female, a, Area occupied
by first-stage armor; b, inner portion of second-stage armor which retains
dark color; c, outer portion of second stage armor which becomes reddish
brown during molt; d, area occupied by armor grown during third stage.
1, Boundary of white cap area; 2, boundary of first-stage armor; 3,
boundary of second-stage armor.
12 Florida Agricultural Experiment Stations
During the summer
the life cycle for Florida
red scale can be com-
pleted in less than six
weeks. The development
is typical of that of other
armored scales and ap-
parently four or more
generations occur each
S year. There is a marked
tendency for the females
to feed on the under sides
of the leaves and the males
on the upper surfaces.
Also, the scales appear to
prefer fruit to foliage in
the late summer and fall,
and clusters of fruit may
be heavily infested while
adjacent leaves sho w
only a few scales.
Florida red scale in-
fests only the leaves and
fruit. In spite of this,
it may cause a very
Fig. 7.-Young grapefruit leaf distorted heavy leaf drop. The
by red scale attack shortly after it had
unfolded. The earlier the attack, the worse defoliated branches then
the distortion will be. The black specks on die. When infestations
the foliage are mostly early second stage
scale. (Slightly enlarged.) are severe, the damage
may be worse than with
purple scale. In numerous instances the authors have observed
almost complete defoliation from red scale, accompanied by ex-
treme loss of bearing wood. Florida red scale is often slow to
develop in the spring, but it may become very severe by August.
Maximum damage usually occurs in late summer and fall.
Florida red scales cause yellow spots on the fruit, just the
reverse of purple scale injury. Thus, a green fruit will be
speckled with yellow spots where live red scales are present.
When red scales attack young fruit they cause pitting, which
may be so severe that the fruit never is able to recover. Such
coarse-peeled fruit will be thrown out of grade. Similarly, young
foliage may be distorted when attacked by young scales (see
Insects and Mites Found on Florida Citrus 13
Fig. 7). This condition is readily confused with the fungus
disease, melanose, which occurs on leaf growth of the same age.
Fig. 8.-Grapefruit with heavy red scale infestations. The large dark
area is beginning to show rind breakdown. This sometimes occurs late
in the season when infestations are severe.
"Chaff scale, Parlatoria pergandii Comst., is found through-
out the citrus area of Florida. This scale forms a light-brown
armor which is slightly smaller than that of a mature female
Florida red scale. The armor is eccentric, but nearly round.
The area of the armor which was occupied by the first stage
scale is at the side of the armor of the mature scale. The insect
itself is purple. So are the eggs and the crawlers. The crawlers
are ovoid in shape and superficially similar to Florida red scale
except in color. Chaff scales infest wood, leaves and fruit.
except in color. Chaff scales infest wood, leaves and fruit.
14 Florida Agricultural Experiment Stations
Fig. 9.-Chaff scale on an orange, along with an occasional purple
The presence of chaff scale is often a major grade-lowering
factor, particularly on tangerines. Live chaff scales prevent
degreening of the fruit to the same extent as purple scales.
Often growers complain of the green spots caused by purple
scale; however, the authors have noted that in many of these
instances the cause was chaff scale rather than purple scale.
Chaff scale is insidious in this respect. When trees are
nearly free of purple scale, it is often assumed by the grower that
scale control is unnecessary. Thus, the foliage may show a
very low-grade scale infestation, but the fruit may be so severely
marked by chaff scale that a high percentage cannot be packed.
It is difficult to anticipate such infestations until shortly before
picking time, but it is probable that close examination of
the fruit in August would make it possible to control chaff
scale in time to allow the normal degreening of the fruit.
Dictyospermum scale, Chrysomphalus dictyospermi (Morg.),
is found almost exclusively on leaves and fruit. Most infesta-
Insects and Mites Found on Florida Citrus 15
tions are reported from Orange and Lake counties in central Flor-
ida. Except in 1936 when infestations were severe, this species
has been a serious problem only in a few individual groves.
Because of the close similarity to yellow scale (Fig. 10), the
two species are difficult to distinguish. Dictyospermum scale
has a light brownish armor which is slightly smaller than that
of Florida red scale. The scale itself and the eggs are pale
lemon-yellow. The adult female undei the armor is definitely
pear-shaped. This shape, the presence of eggs, and the fact that
the armor separates more readily from dictyospermum scale are
characteristics useful in differentiating dictyospermum from
Yellow scale, Aonidiella citrina (Coq.), is occasionally re-
ported on citrus in Florida. It is found most commonly in
coastal areas, particularly in Pinellas County. As does dictyo-
spermum scale, it rarely infests twigs. This scale does not
lay eggs, but produces living young. The adult female has a
kidney-shaped body under the armor. It is practically impos-
sible for the layman to differentiate between yellow and Cali-
fornia red scale. Although California red scale, Aonidiella
aurantii (Mask.), has been reported on ornamentals in Florida,
it has never been found on citrus. For many years it was thought
that yellow scale found on citrus was actually California red
scale. Only in recent years have proper differentiation and
identification been made.
Two similar species of armored scales appear on citrus and
are recognized as snow scales. The major species is the true
citrus snow scale, Unaspis (Chionaspis) citri (Comst.). This
scale is a serious problem in parts of Orange, Seminole and
Volusia counties. The most serious infestations of this insect
have occurred around Maitland, Oviedo and Geneva. Consider-
able injury may be produced by this species.
Snow scale derives its name from the fact that the male
scales have an elongated white armor formed with three ridges
down the back. The infestation of these insects is largely con-
fined to the trunk and large limbs. Where snow scale is numer-
ous, these areas appear to be covered with storm-driven snow.
The female is approximately the size of a female purple scale
16 Florida Agricultural Experiment Stations
and is much the same shape, except that the posterior portion
of the armor is broader than is the case with purple scale. The
females are inconspicuous and difficult to see against tree bark.
The insects themselves are orange to yellow. The crawlers
are ovoid in shape, similar to red scale, and are orange in color.
They may be seen readily with a hand lens as they crawl about
on the bark.
Fig. 10.-Yellow scale on an orange. (Enlarged.)
Fern scale, Pinnaspis aspidistrae (Sign.), is similar in ap-
pearance and, in the past, has been called the lesser snow scale.
However, it is found on leaves and small twigs (Fig. 12), not
on large limbs and the trunk. This scale has been reported
primarily from groves along the upper east coast. It has not been
observed by the authors as a pest of economic importance.
Lepidosaphes gloverii (Pack.) is known as Glover's scale or
in Florida more commonly as long scale. It is closely related
Insects and Mites Found on Florida Citrus 17
to purple scale. The mature female is white under an elongate
brown armor. The armor, quite similar to that of purple scale,
is more elongate and narrower. The life history of these two
species is similar.
Fig. 11.-Snow scale on the trunk of a citrus tree. The white areas are
the result of an accumulation of male scales.
18 Florida Agricultural Experiment Stations
This species has a history of being a primary citrus pest. As
early as 1885 Hubbard (18) described it as the major citrus
scale insect. At that time most of the citrus in Florida was
located north of Ocala and along the St. Johns river. Long
scale is apparently a
species which is
adapted to a colder
climate than purple
"scale. Natural ene-
mies may have been
a factor, but after
the citrus industry
shifted south to the
central Florida sand-
hills following t he
1894-95 freeze, long
scale ceased to be a
specimens are regu-
larly encountered all
over the state, but
infestations of eco-
nomic importance are
not known to occur.
During the summer
of 1951, in a 1500-
acre planting, one
three year old tree
was found which was
with long scale.
Fig. 12.-Fern scale on citrus leaves. The Leaves, twigs and
clusters of white males are typical of an in-
festation by this scale. (About natural size.) fruit were covered
and the tree was in
serious condition. However, no other trees in the entire grove
appeared to be affected by this insect.
CHEMICAL CONTROL OF ARMORED SCALES
Most groves require an annual scalicide spray for the control
of either purple or Florida red scale. In an occasional grove
Insects and Mites Found on Florida Citrus 19
one of the other armored scale species may also require control.
Methods of spraying and the materials used are essentially the
same for all species (55, 56). See the Spray and Dust Schedule
of the Better Fruit Program.
Thorough coverage is extremely important in controlling
scales. Complete coverage of fruit, leaves and wood is essential.
A scalicide spray requires more gallons per tree than any other
Fig. 13.-Long scale on a citrus leaf. The long, slender individuals
are mature females. These are about the same length as purple scales,
but the armor is more slender. (Three times natural size.)
Citrus snow scale presents a special problem. These insects
are found most commonly on trunks and large limbs. When
hand spray methods are used, the trunks should be sprayed
from the bottom up. Care must be taken to cover all bark
Chaff scale occasionally presents a special problem on tan-
gerines in the fall. When such infestations are noticed before
September, a recommended spray should be applied (see the
Better Fruit Program).
20 Florida Agricultural Experiment Stations
BIOLOGICAL CONTROL OF ARMORED SCALES
Entomogenous Fungi.-For many years so-called "friendly"
fungi were thought to kill scale insects in Florida. Watson and
Berger (58) dwelt on this idea at great length. Ziegler (61),
at a meeting of the Florida Entomological Society in 1935, pre-
sented information to show that the red-headed fungus (Sphaero-
stilbe aurantiicola (Berk. & Br.) Petch and pink-headed fungus
(Nectria diploma B. & C.) were in all probability saprophytes
rather than parasites. Subsequently Fisher (5) carefully re-
viewed the entire problem and concluded that such was the
case, but that there are at least two species of fungi which at-
tack and kill purple scale. Red and pink fungi on scales indicate
only that the scales are dead. The incidence of these fungus
species often increases greatly following an oil spray.
In 1947 Fisher (5) described a species of chytrid, Myio-
phagus sp. Thaxter, which attacks second and third stage pur-
ple scale. The scale changes from a pearly white through a
pinkish stage to a cheesy golden color. While this species of
fungus can be seen only through a hand lens, there can be no
question that it is a major factor in the reduction of many purple
Fisher (6) also reported a fungus, Hirsutella Besseyi Fisher,
which was associated with dead crawlers and first-stage purple
scales. She stated that it either killed the scales or was a specific
indicator of some other causal agent. Its presence is often
associated with heavy mortality among young scales. This
species of fungus cannot be identified by the grower in the field..
Entomogenous fungi are major factors in the biological con-
trol of purple scale, but they are probably of minor importance
on Florida red scale.
Predaceous Insects and Mites.-Three species of ladybeetles
have been recorded by Muma (24) as primarily predaceous on
citrus armored scale insects. On occasion, all three have been
found in abundance among scale infestations. The most com-
mon species on citrus is the twice-stabbed ladybeetle, Chilocorus
stigma (Say) (Fig. 14), which reaches a population peak in
the spring and summer (24). The adult, from 1/6- to 1/8-inch
long, is black with a pair of small red to orange spots in the
middle of the back. Its orange eggs are often found under
scale armors. The larvae are black and quite spiny. The pupae
Insects and Mites Found on Florida Citrus 21
are found on the underside of branches and twigs and may be
present in very large numbers. These beetles are most readily
found on fruit where heavy Florida red scale infestations are
The little scale-eating ladybeetle, Microweisea coccidivora
Ashm., is very tiny and easily overlooked in the field. Adults
are less than 1/16 inch long. They are
black except for spots or a band of ma-
hogany red on the back (see Fig. 15).
Larvae are small and greyish. They feed
on all stages of scale insects.
The little red ladybeetle, Exochomus
marginipennis children Muls., also feeds
on scales, but is rarely present in large
numbers. The fore part of the body is
black while the wings are orange to red, 4
except for a pair of connected black spots Fig. 14. Twice-
on the very back end of the wings. The stabbed ladybeetle
larvae are black and spiny with bars and larva (enlarged).
These ladybeetles are
spots of white. often seen feeding on
Two mites have been shown to feed on h a vinfe iods. red
scale eggs and crawlers (23). These are
Amblyseius quadripilis (Banks) and Typhlodromus peregrinus
Muma (31). It is probable that the thrips Aleurodothrips
fasciapennis (Franklin) and Leptothrips mali (Fitch), also
feed on scales as they are commonly seen in the midst of scale
infestations (23, 32).
Fig. 15.-The three ladybeetles which feed on scale insects. Left to
right: The little scale-eating ladybeetle in two color phases; the little red
beetle; and the twice-stabbed ladybeetle. Actual sizes are 6, A to %s, and
/s to %Y inch in length, respectively. (Original drawings by M. H. Muma.)
A mealywing or dustywing, Coniopteryx vicina (Hagen),
has been found to feed on scale crawlers (34). Trashbugs and
22 Florida Agricultural Experiment Stations
aphid lions feed on scales occasionally, but are probably not
Fig. 16.-Two thrips predatory on scales: Left, the
brown and yellow thrips, Aleurodothrips fasciapennis,
and right, the black hunter, Leptothrips mali. (En-
larged.) (Original drawings by M. H. Muma.)
Parasitic Insects.-At least four species of parasitic wasps
are found in either Florida red or pur-
ple scales. Pseudhomalapoda prima
(Gir.) is a third-stage red scale para-
site (23, 54). Aspidiotiphagus citrinus
(Craw.) has been collected from second-
stage red scale (23). A. lounsburyi (B.
& P.) and Prospaltella aurantii (How.)
have been found in both second-stage
Fig. 17.-Dustywing Florida red scale and purple scale (23).
It is probable that insect parasitism is
much more important in the control of Florida red than pur-
The unarmored or soft scales are readily recognized as scale
insects, but they are not always easily differentiated from the
Insects and Mites Found on Florida Citrus 23
armored species. Although many have a tough upper covering,
this is actually a part of the insect and not a non-living armor
as in the case of the armored scales. This skin or dermal cover-
ing many become quite tough and rigid in some species. Soft
scales retain their legs throughout their entire life and will
move from a location, if it becomes undesirable. All species in
Florida are heavily parasitized. As a result, they are rarely of
major economic importance.
The unarmored scales secrete honeydew abundantly. Sooty
mold, Meliola camelliae (Catt.) Sacc., is a fungus which grows
on the honeydew, causing leaves
and fruit to be covered with a
film of black, sooty material.
Ants which feed on the honey-
dew are commonly associated
with soft scale infestations.
SOFT BROWN SCALE
Soft brown or turtle back
scale, Coccus hesperidum L., is
the most common of the several
species of unarmored scales
found on citrus. The upper skin
of the scale takes on a waxy,
almost parchment-like appear- Fig. 18.-A soft brown scale
much enlarged, showing emer-
ance as the scale matures. The gence hole of a parasite. The two
females are ovoid and markedly light areas mark the space occupied
by the two parasites that killed
flattened. They are brownish the scale.
in color and may have a mottled
appearance. Larger than any of the armored scales, they may
measure almost as much as 1/6 inch in length.
They commonly infest the young twigs of a tree and often
gather along the midrib of the leaf. The females do not lay
eggs and the crawlers are born alive. There are several gener-
ations a year. Because of the high rate of parasitism, they rarely
become abundant except on young trees, either in a newly
planted grove or in a nursery. The following parasites have
been found in them in Florida: Microterys flavus (How.),
Lecanobius cockerellii Ashm., Coccophagus lycimnia (Walk.), C.
scutellaris (Dalm.), and Aphycus flavus How. (Muma, unpub-
24 Florida Agricultural Experiment Stations
In the fall of 1950 a severe infestation of soft brown scale
spread over the larger part of about 600 acres near Lake Placid.
This infestation arose as the result of several parathion appli-
cations in one year, which had destroyed the parasitic insects.
The infestation was exceptionally severe and the fruit and leaves
were coated with sooty mold. The sooty mold conditions must
have been comparable to the conditions caused by whitefly in
the years just after the turn of the last century. The damage
done in this grove was difficult to assess because of a simul-
taneous Florida red scale infestation and dry weather compli-
Fig. 19.-Sooty mold on grapefruit following a very severe infestation of
soft brown scale. Note tear stains on fruit at left.
Black scale, Saissetia oleae (Bern.), resembles soft brown
scale during its young stages. As the scales mature the upper
skin becomes tough and thickened, with two longitudinal ridges
connected by a cross ridge so that a pattern resembling a letter
"H" is formed. The thick skin resembles the armor of the ar-
mored scales. The female, similar in size to soft brown scale,
is dark brown or almost black. The under side of the scale has
a pinkish-to-purplish cast. The eggs, which are definitely pink,
are found in very large numbers under the female.
Insects and Mites Found on Florida Citrus 25
Under Florida conditions two generations are produced each
year. The first generation usually reaches adulthood in June.
These scales have a pronounced affinity for small twigs and
particularly for the stem which holds a fruit. In June of 1950,
relatively heavy infestations occurred in numerous groves. Ac-
tually the scales did little damage but they were so common that
growers were alarmed throughout the state. Populations of
the scale were lower in 1951 and 1952. No reason for the ex-
ceptional numbers in
1950 can be offered. The
scale is ordinarily con-
trolled by a predaceous
insect and it is possible
that there was an upset
in the normal biological
balance. The larva of
Scutellista cyanea Mots.
is an egg predator. It
is found in the midst of
eggs under the black
(Targ.), is closely re-
lated to black scale and
closely resembles the two
particularly in the Fig. 20.-Black scale on a Temple orange
younger stages. It is twig. Note the young scales scattered over
the fruit. The stem holding the fruit is a
comparable in size to preferred place for black scales to settle.
black scale, but its body
is more rounded and is almost a true hemisphere, hence the
name. The upper skin is dark and shiny with no ridges as
in black scale. It is rarely found on citrus but is common
on ornametal shrubs.
Three species of wax scales, genus Ceroplastes, have been
found on Florida citrus. Florida wax scale, C. floridensis Comst.,
is the most common, but except in one grove it has never been
26 Florida Agricultural Experiment Stations
observed to be a real pest. It has a very striking appearance.
When immature, it may be noted on the foliage as a pinkish
glob of wax having four
white structures on the
sides and others at both
the anterior and pos-
terior tip of the insect.
These structures give it
''' an almost star-like ap-
pearance. As the scale
matures these become
less and less prominent.
The adult female scale
may be almost 1/8 inch
in diameter. She has a
pinkish coloration. The
females lay eggs and, ac-
cording to Watson (58),
there are three gener-
ations a year.
The barnacle scale,
formis Comst., rarely
found on citrus, is never
of economic importance.
It is larger than Florida
Fig. 21.-Hemispherical scale on twig wax scale and its height
(enlarged). wax scale and its height
Fig. 22.-Florida wax scale on orange leaf (natural size). Note the tiny
scale and the change in its appearance as its grows.
Insects and Mites Found on Florida Citrus 27
is almost equal to its width. The waxy coat is divided into plates
which are more distinct than on Florida wax scale. In addition,
there is a spine-like structure located at one end of the scale.
This species is also darker in color than Florida
wax scale, but its life history is similar.
Japanese wax scale, Ceroplastes ceriferus (An-
derson), is occasionally found on citrus. It is larger
than either of the other two species.
Green scale, Coccus viridis (Green), was first
reported in Florida in 1942 (9) near Davie, on the
lower east coast. It was found to be widespread
on other host plants and presumably had been in
Florida for several years. On citrus it is appar-
Plant Board cut
ently confined to
groves along the
lower east coast. It
is green and more or
less transparent. The
young scales may be
confused with green
shield scale (see be-
low), but the adult
differs in that it does
not have an egg sac
Fig. 24.-Green scale (enlarged seven times). outside the body. The
(State Plant Board cut after Merrill.) scale measures up to
28 Florida Agricultural Experiment Stations
about 1/8 inch in length and is
about half as wide as long. It
is a parthenogenetic species (9),
that is, it produces young with-
out mating. These scales are
usually found along the base of
the midrib on the under side of
the leaf. On heavily infested
leaves there may be over 200 per
leaf. Scales have been reported
on orange, grapefruit and lime
Fig. 25.-Adult pyriform scale
GREEN SHIELD AND on avocado leaf. Note white halo
PYRIFORM SCALES about the insect. (Enlarged about
The green shield scale, Pulvi-
naria psidii Mask.,
and the pyriform (Ckll.), are
scale, Pr iftoni,6 closely related
naer, pPt,'f)rt, is species which are
a4 only occasionally
found on citrus.
The adults of both
have a rather un-
and so may be
The mature fe-
males of both
species have a
egg sac (20). In
the case of the
green shield scale
the egg sac be-
comes quite long,
the female and is
largest at the
scale female is
Fig. 26.-Green shield scale (enlarged twice).
(State Plant Board cut after Wilson.) surrounded by a
Insects and Mites Found on Florida Citrus 29
halo of this cottony wax and the egg sac never enlarges beyond
this stage. Pyriform scale is brown in color and triangular in
shape. It measures from 1/8 to 1/6 inch in length. Green shield
scale may be slightly larger and is green.
CONTROL OF SOFT SCALES
Control of soft scales is essentially the same as for armored
scales. However, sprays seldom are required for soft scale con-
trol. Little experimental evidence has been accumulated con-
cerning the control of these insects. They are most apt to require
control either in a nursery or on occasional isolated trees. (See
the Better Fruit Program for specific recommendations.)
INSECTS RELATED TO SCALES
COTTONY CUSHION SCALE
Cottony cushion scale, Icerya purchase Mask., was introduced
into Florida in Pinellas County in 1893. It is now generally
distributed throughout the citrus area. However, at present it
is rarely of economic importance, except on young trees and
in nurseries. Occasionally in old groves an individual limb may
be seriously affected, but the infestation in the
grove will be confined to the one limb. Honey-
dew secretions result in ant attendance and the
formation of sooty mold.
The young scales are reddish to brown.
Some yellow, waxy threads often extend from
the body and cause a hairy appearance. The
young tend to congregate along the midribs of
the leaves and along twigs. As the female ma-
tures, a fluted white egg sac begins to grow out
from under her reddish back. After the egg
sac is fully formed the female may measure Vedalia lady-
about % inch in length. The egg sac is white beetle. It is red
and black and
and grooved or fluted. The red color of the approximately 1
young and the reddish plate at the fore end of inch long. (Orig-
the egg sac readily distinguish this species from na. H. uma.)
Formerly, control was entirely dependent upon the Vedalia
ladybeetle. This ladybeetle, Rodolia cardinalis (Muls.), is about
1/8 inch long and is black and red in color (24). The larvae are
red and are easily confused with the young scales. The Vedalia
30 Florida Agricultural Experiment Stations
beetle almost always is found in an infestation of cottony cushion
scale. Prior to the introduction of phosphatic compounds,
no insecticide was known which would satisfactorily control
this pest. However, it is rare that chemical control is required
except in nurseries or young groves. (See the Better Fruit Pro-
gram for specific recommendations.)
Fig. 28.-Cottony cushion scale on a citrus twig. Note young scales
on the leaf (slightly enlarged).
Mealybugs are white and are characterized by a definitely
segmented body which is covered with mealy white wax. There
may be distinct lateral filaments and/or tail-like filaments at
the posterior end of the insect. Two species of mealbugs are
found on citrus in Florida. The common one is the citrus mealy-
Insects and Mites Found on Florida Citrus 31
bug, Pseudococcus citri (Risso). A second species, P. brevipes
(Ckll.), the pineapple mealybug, is reported by Merrill (20)
as having been found on citrus.
Mealybugs are most common during the spring and early
summer. Then they may become so numerous following the
set of fruit that their
feeding under and ad-
jacent to the button of
the young fruit causes
fruit drop. This may
materially reduce the
quantity of the crop.
Similarly, mature fruit
will drop prior to har-
vesting and thus be lost
to the grower. When
are severe this represents
a major fruit loss to
many growers. If mealy-
bugs are present and Fig. 29.-Citrus mealybug. These in-
dividuals are about full grown. (Twice
feeding upon fruit dur- natural size.)
ing the summer months
they cause hard lumps to develop on the rind. These lumps lose
their green color prematurely, resulting in a low-grade fruit.
Grapefruit are much more subject to these injuries than any
other variety of citrus in Florida.
Under Florida conditions several generations occur during
the year, but only one cycle is of major concern to the citrus
grower. During the spring, at a time roughly coincidental with
the blooming period, egg masses are deposited on the trunk and
large limbs of the trees. They appear as little white patches
of cotton scattered about on the tree trunk. When infestations
are heavy the large limbs and trunks will be speckled with these
little white masses (see Fig. 31). The young mealybugs are
creamy in color with small white waxy particles clinging to
them. They crawl out onto the twigs and will hide in any crevice
or niche, but most commonly are found under the button or
calyx of the fruit. Where two or more fruit are in a cluster,
as is often the case with common or seedy grapefruit, they tend
to collect in the areas where the fruits are touching. If a leaf
is clinging to a fruit, they will be found in this space. When
32 Florida Agricultural Experiment Stations
mealybugs are young, their presence under the calyx of the
young fruit may be evidenced only by the presence of sooty
mold, which has followed the secretion of honeydew by the
Fig. 30.-Citrus mealybugs on red grapefruit, showing the accumulation
of mealybugs and sooty mold.
Following the hatch of the first generation, mealybug in-
festations usually reach a peak in June or July. With the ad-
vent of rainy and warm weather, populations are rapidly re-
duced. This is probably due in most instances to the fungus
Entomophthora fumosa Speare (41). Occasionally, and par-
ticularly in grapefruit groves, mealybugs persist in fair numbers
throughout the summer and into the fall.
The Australian mealybug ladybeetle, Cryptolaemus mon-
trouzieri Muls.; the little mealybug-eating ladybeetle, Decadio-
mus bahamiczs (Csy.) ; and the pictured ladybeetle, Scymnus
Insects and Mites Found on Florida Citrus 33
flavifrons Melsh. feed primarily on mealybugs (27). In addi-
tion a brown lacewing, Sympherobius barber (Banks) ; a green
lacewing, Chrysopa lateralis Guer.; and a large unidentified
trash bug all feed on mealybugs (Muma unpublished data). Two
other ladybeetles f e e d
occasionally on mealy-
bugs. These are Chilo-
corus stigma (Say) and
Olla abdominalis v ar .
plagiata Csy. The three l
species of parasites
which have been identi- p
fied on mealybugs are
(Grit.), Leptomastix .
dactylopii How., and
dens How. (Muma un-
published data). Two
unidentified wasps also
have been noted.
When large numbers
of egg masses are found
on the trunks and large
limbs in the spring, con-
trol measures should be
planned. Timing of
sprays is of considerable
tions made before the Fig. 31.-Mealybug egg masses on trunk
spring flush of growth and large limbs of a tree. Such conditions
have been most effective, are most likely to occur during late spring.
(Photo by J. C. Wolfe.)
After the spring flush
occurs, the spray should be applied as soon as the bulk of the
eggs have hatched. This will usually coincide with a post-bloom
spray. It is easier to kill the mealybugs while they are small
and before they find hiding places for themselves. See the
Better Fruit Program for the specific insecticide.
Whiteflies are tiny fly-like creatures with a white dusty wax
covering on the wings. They are not true flies and are actually
34 Florida Agricultural Experiment Stations
more closely related to the scale insects and mealybugs. First
stage nymphs have legs and move about freely. The nymphs
are ovoid in shape and, because they are almost transparent
thin, they share
the green color of
the leaf and are
ous. The eggs of
the whitefly are
tiny, but when
many are laid to-
Fig. 32.-Three ladybeetles which feed primarily
on mealybugs. Left to right: Decadiomus ba- gether they are
hamicus; Scymnus flavifrons; and the Australian readily seen with
mealybug ladybeetle, Cryptolaemus montrouzieri.
These measure 1/20 to 1/16, 1/6 and 1/8 to 1/6 inch the naked eye as
in length, respectively. (Original drawing by M. H. a dusty area on
Mma.) the under side of
new succulent foliage. The nymphs attain a length of about
1/25 inch at their maximum. At the conclusion of the nymphal
period, a pupa stage is undergone during which time wings are
formed. The adults emerge by way of a split in the skin of the
pupa. The old pupa cast skins appear as whitish ovoid struc-
tures on the under side of the leaves. They are often seen by
the grower. The adults are winged and are often seen in tre-
mendous numbers in citrus groves. As many as four gener-
Fig. 33.-Left: Cloudy-winged whiteflies on a citrus leaf. Note the
tiny cloudy areas at the posterior tips of the wings. The black specks
on the leaf are eggs. (Enlarged three times.) Right: Unusual arrange-
ment of whitefly eggs. It is most typical of woolly whitefly.
Insects and Mites Found on Florida Citrus 35
nations may occur in one year. During the spring and early
summer when there is little overlapping of generations, hordes
of adults appear at the same time in many groves.
Only three species of whitefly are commonly found on citrus
in Florida. These are the cloudy-winged whitefly, Dialeurodes
citrifolii (Morg.) ; the citrus whitefly, D. citri (Ashm.) ; and the
woolly whitefly, Aleurothrixus floccosus (Mask.). According to
Watson (58), four other species are occasionally found on citrus,
but never in sufficient numbers to constitute an economic prob-
lem. Since they are difficult to distinguish from the common
whiteflies which are usually present, they are mentioned only
Bay whitefly-Paraleyrodes perseae (Quaint.)
Sweet potato whitefly-Bemisia inconspicua (Quaint.)
Mulberry whitefly-Tetraleurodes mori (Quaint.)
Avocado whitefly-Trialeurodes floridensis (Quaint.)
Shortly after the turn of the 20th century whiteflies were
considered to be major pests of citrus in Florida (22). Appar-
ently they were much more common then than now and entomo-
genous fungi which usually control them were not so prevalent.
According to men who were working on citrus in those years,
the sooty mold which followed the honeydew secretions was
exceptionally dense. The trees would be so completely covered
with honeydew as to be almost dripping with it. In turn the
honeydew was attacked by sooty mold. Any interference with
the physiological functioning of leaves as a result of the shading
effect of sooty mold has never been reported in Florida. That
such concentrations of sooty mold adversely affected the trees
was generally believed, and it was shown that heavy deposits
of sooty mold delayed natural degreening (22). In addition,
sooty mold required that the fruit had to be washed before
being packed. In those days fruit was seldom washed and sooty
mold added another expensive procedure to the packing house
operation. This was undoubtedly a factor in the belief that
whiteflies were such an important problem to the citrus grower.
Infestations are such today that growers rarely if ever apply
a spray expressly for whitefly control. Although their economic
importance today is of little concern, whiteflies are widespread
and occur in most groves.
Cloudy-winged and Citrus Whiteflies.-These two species are
often found in mixed populations, but there is a tendency for
36 Florida Agricultural Experiment Stations
the citrus whitefly to be the predominant species in the northern
part of the citrus area and the cloudy-winged species to be more
important in central and southern Florida. Economically, dif-
ferentiation is of no importance. However, they may be separated
in the field on the basis of several characteristics. The eggs
of both species are laid primarily on the underside of the leaf.
Watson (58) stated that the eggs of the cloudy-winged whitefly
are black while those of the citrus whitefly are yellow. A better
characteristic is the presence of sculpturing on the eggs of the
cloudy-winged whitefly. Citrus whitefly eggs have no sculptur-
ing and are very shiny.
In the case of the adults, the cloudy-winged species has a
slightly darkened area in the center and at the tip of each wing
(Fig. 33). The yellow Aschersonia fungus attacks only the
nymphs of the cloudy-winged whitefly, and its presence is a good
indication of the species involved.
Whitefly nymphs are found almost exclusively on the under
side of the leaves, but occasionally they will be found on fruit
as well. The honeydew secretions, of the whitefly drip onto the
leaves below and sooty mold grows mainly on the top side of
Whiteflies are controlled by several species of entomogenous
fungi. The red and yellow Aschersonia fungi are the most
common. They are brilliantly colored and often form a startling
sight for those who observe them for the first time. Brown
fungus is most common in Lake and Orange counties and is
often mistaken for Florida red scale by the inexperienced in-
dividual. Five species (58) of whitefly fungi are recorded:
yellow Aschersonia, Aschersonia goldiana Sacc. and Ellis; red
Aschersonia, Aschersonia aleyrodis Webber; brown whitefly
fungus, Aegerita webberi Faw; white fringe fungus, Fusarium
aleyrodis Fetch; and cinnamon fungus, Verticillium cinnamon-
eum Petch. These are major factors in the natural control of
The ladybeetles Delphastus pusillus (Lec.), D. pallidus
(Lec.), Scymnillodes subtropicus (Csy.), and Nephaspis gorhami
(Csy.) feed primarily on whiteflies (26). D. pusillus differs from
most ladybeetles by having a life cycle of only three weeks (33).
Woolly Whitefly.-The history of the introduction of woolly
whitefly, Aleurothrixus floccosus (Mask.), into Florida is some-
what obscure (57). In 1909 it was found in groves near Tampa.
Insects and Mites Found on Florida Citrus 37
It had been reported as a pest in Cuba some six years previously.
Although an apparently identical species had been recorded on
sea grapes in Florida 25 years before, citrus had not been a re-
ported host prior to 1909. For several years after its discovery
on citrus, it was a severe pest in many areas and whole groves
were heavily infested.
Fig. 34.-Whitefly larvae killed by fungi. Yellow fungus is on the
left leaf, red on the right. The bright colors make a startling picture
in a citrus grove. Note that yellow fungus appears smaller than red.
The woolly whitefly is characterized by a wool-like group
of waxy filaments surrounding the pupa and a smaller waxy
fringe about the nymphs. Although woolly whitefly is present
throughout most of the citrus area, it is not a real economic
problem. The adult is similar in appearance to those described
38 Florida Agricultural Experiment Stations
Fig. 35.-The ladybeetles which feed on whiteflies. Left to right:
Little tan ladybeetle; little black and white ladybeetles, male and female;
little black ladybeetle; and little steel blue ladybeetle. These measure
1/25, 1/20, 1/16 and 1/16 inch, respectively. Original drawings by M. H.
The nymphs exude copious amounts of honeydew; often there
is a large drop attached to the posterior end of a nymph. Honey-
dew causes a very sticky condition, and if this part of the leaf
is touched inadvertently by an observer, a surprising sensation
Fig. 36.-Bay whitefly laying eggs in nest-like structure on a citrus leaf.
Insects and Mites Found on Florida Citrus 39
Control of Whiteflies.-Many years ago, whiteflies regularly
required control. Today sprays are rarely, if ever, applied
specifically for whitefly control. Whiteflies are automatically
controlled by the sprays applied for scale. However, the high-
est percentage of kill is obtained where the spray application
is made soon after the eggs have hatched.
Several species of mites are of economic importance on citrus.
Of these the most important is the citrus rust mite. The remain-
ing mites are divided into three groups: the true spider mites,
the false spider mites, and a Tarsonemid mite.
CITRUS RUST MITE
The rust mite, Phyllocoptruta oleivora (Ashm.), is a tiny
wedge-shaped creature, yellow in color and about 1/200 inch
long. It can be seen only with the aid of a hand lens. When
there is a severe infestation on fruit or foliage, there is a dusty
condition which is readily recognized by experienced grove men.
This dustiness indicates the presence of myriads of living mites
and cast skins shed during the molting process.
The life cycle of this mite from egg to egg is 7 to 10 days (60)
under warm temperature conditions, so that infestations often
increase very rapidly. Heavy infestations may occur at any
month of the year, but there is a tendency for infestations to
increase during the spring and reach maximum proportions dur-
ing the summer, with lower infestations generally occurring
during the late fall and winter months.
Rust mites are associated with injury on both leaves and
fruit. The injury to fruit (see Plates II and III) is the primary
concern of most growers, but leaf injury also is important.
Others and Mason (60) were unsuccessful in reproducing rust
mite injury on fruit by artificial means, but there has been a
widespread belief by growers, as reported by Spencer and Osburn
(42), that fruit injury was the result of the puncture of oil cells.
This is apparently incorrect. It has been demonstrated (60)
that the epidermal cells of the fruit are damaged by rust mite
feeding. This was substantiated by R. M. Pratt (unpublished)
in 1957. He actually photographed the mouth parts in the
epidermal cells. The exact nature of rust mite injury is further
complicated by the work of Fisher (8) in 1956. She found a
fungus associated with rust mite lesions and suggested that
40 Florida Agricultural Experiment Stations
rust mite injury in the late summer and fall might be affected
by a fungus.
The injury which develops differs, depending on time of
injury and variety of fruit injured. In the case of grapefruit
and lemons or limes, injury during the early months of the
fruit's growth will cause a silvering of the peel and, if severe,
may result in a condition knows as "sharkskin". When this
occurs early enough fruit size is materially reduced. In the
case of oranges, the early injury results in a brown cracking
and scarring of the surface. Such fruit will not take a sheen
when polished. When the fruit is mature, this injury is called
russeting. As noted above, if severe, fruit size is reduced. On
Valencia oranges, at least, this type of injury may occur as late
as August and possibly later.
Late injury as compared with early injury is a smooth brown-
ish staining. On grapefruit the injury appears to start at the
site of the stomata between the oil cells. Late injury takes a
high polish and is called bronzing. It is considered by some
Fig. 37.-The tree in right foreground was sprayed three times with
lime-sulfur. Those on the left received only one sulfur spray, and rust
mite populations were heavy throughout the summer and fall. Although
greasy spot developed in both areas, it was much more severe on the
limited spray program where defoliation occurred.
Insects and Mites Found on Florida Citrus 41
people to make fruit more desirable, and such fruit brings pre-
mium prices in some markets because it is said to be sweeter
than uninjured fruit. This is apparently true if the fruit is
tested a number of days after picking. Fruit injured by rust
mite loses moisture rapidly, which results in a concentration of
the juice with a correspondingly higher percentage of sugar.
Leaf injury is manifested by several symptoms. Heavy in-
festations on the leaves and green twigs may cause a general
leaf drop similar to that caused by the purple mite. This type
of injury is most likely to occur in late fall, winter and early
spring months during periods of dry windy weather. Heavy
infestations sometimes cause the under surfaces of leaves and
the green twigs to turn a brown rusty color. Apparently there
is some unknown factor present, because it is the exception
rather than the rule for russeting of the leaves to occur follow-
ing a heavy infestation.
A condition known as "greasy spot" or "greasy melanose"
on leaves has been attributed to rust mite injury (49), but more
recent work by Fisher (7) and Tanaka and Yamada (43) has
demonstrated that greasy spot is a fungus belonging to the
Cercospora group. This injury is characterized by the forma-
tion of small yellowish brown areas with an oil-soaked appear-
ance on the under surfaces of the leaves. These areas expand
in size and become raised and hard and are dark brown to
black. Although the raised areas are usually on the under
surface of the leaf, the injury is apparent on the upper surface
in the form of brown or black spots. Observations to date indi-
cate that the spring and early summer flushes of growth are
more severely affected than a late summer or fall flush. Leaves
affected with greasy spot drop prematurely and if a high per-
centage of leaves are affected, a heavy leaf drop occurs between
October and March.
Even though it has been established that a fungus is the
primary cause of greasy spot, rust mite injury should not be
ruled out as a secondary factor until more work has been done.
An injury similar to greasy spot has been observed by the
authors following infestations of purple scale, red scale and six-
spotted mites. However, it has been found by Fisher (7),
Thompson (51, 53), and Griffiths (14) that a summer copper
spray resulted in the control of greasy spot. Oil emulsions also
have reduced the amount of greasy spot. Where rust mites
42 Florida Agricultural Experiment Stations
were controlled with lime-sulfur and wettable sulfur combina-
tion sprays throughout the year, greasy spot was not as severe
as where heavy infestations of mites were allowed to develop
(51) (Fig. 37). Until more definite conclusions can be drawn,
rust mite injury should be considered as a secondary factor
and fungus as the primary factor in the cause of greasy spot.
Fig. 38.-Greasy spot on citrus foliage. Note the lumpy, discolored areas.
Citrus Rust Mite Control.-For many years rust mites have
been controlled by the use of some form of sulfur. Three to
five applications per year of a miticide usually are required.
These are most often applied as a dormant sulfur spray in late
December or January, a post-bloom sulfur application, a summer
spray of oil or sulfur in June or July, and one or two more sulfur
treatments during late summer and fall. In 1956-57, after Fran.
E. Fisher's (8) use of zineb, R. W. Johnson and J. R. King
(unpublished) found that this material was very effective for
killing rust mites.
Under natural conditions rust mites are killed by a fungus,
Hirsutella Thompsonii Fisher (6). On occasion this fungus is
capable of almost completely eliminating rust mites from a grove.
Insects and Mites Found on Florida Citrus 43
Rust mites are fed upon by the black hunter thrips, Leptothrips
mali (Fitch) (32), the larva of an unidentified fly, and the adult
of the dusty wing, Coniopteryx vicina (Hagen) (34).
The term spider mite refers to a group of mites, usually red
in color, which are associated with various cultivated plants.
Any one of these may sometimes be referred to as a red spider
or red mite. The citrus red mite is the approved common name
for a particular species occurring on citrus in many areas and
is called by that name, except in Florida where it has been
called the purple mite. A similar species, brownish in color and
apparently becoming more abundant in Florida, is named the
Texas citrus mite. Another similar species of importance, which
is straw-colored and spotted, is called the six-spotted mite.
Fig. 39.-Purple mite (citrus red mite) male (left) and female. Males
and young females are red, but adult females have a definite purple color.
The female measures about 1/20 inch in length. (Original drawing by
M. H. Muma.)
The citrus red mite, Metatetranychus citri (McG.), is com-
monly called the purple mite in Florida. It is unfortunate that
44 Florida Agricultural Experiment Stations
the name used for this pest in Florida citrus circles has not been
in accord with the approved naming used in other areas. The
local name of purple mite has been used in this bulletin, with
frequent reference to the correct terminology of citrus red mite,
as a starting point toward putting the correct approved common
name into use by Florida citrus people.
The purple mite was considered to be of little practical im-
portance prior to the late 1930's. At that time (40) a condition
originally thought to be caused by the withertip fungus, Col-
letotrichum gloeosporioides Penz., was found to be caused by
heavy infestations of this mite. This attracted interest in its
control. Since then, infestations of this pest have steadily in-
creased and today it is a major problem throughout the citrus
The life history of this mite is typical of that for red spiders
(39). The eggs are laid on foliage, on green succulent twigs,
and on fruit. They are most commonly found on leaves and
Fig. 40.-Leaves showing mesophyll collapse. Note light areas in leaf
on right where mesophyll cells have been destroyed. This can be seen only
if leaf is held up to the light. If such leaves continue to hang on the tree,
dead areas will form, as shown on the two leaves at the left. This type
of injury most commonly occurs on spring flush foliage in May and
Insects and Mites Found on Florida Citrus 45
green twigs. The areas on either side of the midrib, on the
top side of the leaf and particularly near or on the petiole are
apparently the most desired locations for oviposition. Under
a strong lens the egg may be seen to be characterized by a vertical
Fig. 41.-Tree damaged by purple mites. Note bare twigs, especially
at top of tree, and leaves on the ground. Injury was primarily on late
46 Florida Agricultural Experiment Stations
stalk extending upward from the center, to which are attached
a variable number of threads which look like guy wires. The
eggs are about 1/200 inch in diameter and may be seen readily
with a hand lens. They are deep red before hatching and are
colorless after hatching occurs.
The young purple mite passes through three immature in-
stars. In the first stage it has only six legs and is light red
Fig. 42.-Twigs from which several leaves have dropped following
a purple mite infestation. Note that the leaf petioles remain with the
twig. This is one of the conditions commonly called mesophyll collapse.
Insects and Mites Found on Florida Citrus 47
in color. After the first molt it has eight legs. It molts twice
more to attain adulthood. The young mites are similar in ap-
pearance to the dults but are often somewhat lighter in color.
The adult female is about 1/70 inch long and oval in shape.
She is usually a deep red to a purple color and hence the name,
purple mite. The male is smaller, has a more pointed abdomen,
and is more reddish in color.
The entire life cycle may be passed in about 21 days under
warm temperature conditions. Infestations may develop any
time of the year but, in general, heavy infestations occur after
early November, with the peak infestation usually reached in
May or June.
The purple mite prefers to feed upon the upper surface of
the leaf, the first feeding punctures being found near or on the
petiole. These are in the form of light greyish looking dots
which appear to form lines or scratches on the leaf. As injury
increases, the whole leaf and tree may take on a greyish cast.
Injury may be so severe on spring flush growth that the trees
will look hard and hungry as though an application of fertilizer
had been omitted. As infestations increase, the mites feed upon
succulent twigs as well as on foliage and fruit.
Fig. 43.-View of orange tree with mesophyll collapse and defoliated
twigs. Note, in center, leaves which have died and remained in place.
This condition is often termed "firing."
48 Florida Agricultural Experiment Stations
Aside from the greyish color of the leaves, there are two
common types of injury. One is called mesophylll collapse".
Under certain conditions the mesophyll cells of the leaf collapse
and the tissue becomes a light yellowish green (Plate I and
Fig. 40). If the in-
jury is severe the leaf
tissue in that area
dies. Mesophyll col-
S lapse may occur fol-
lowing dry windy
weather where no
mites are present,
but if mites are pres-
ent the injury is
much more severe.
It may develop on
Fig. 44.-Ladybeetles which feed on spider mature foliage in the
mites, Olla abdominalis left, Stethorus utilis fall and winter, but
right. (Actual sizes about 1/4 and 1/16 inch.) rti larl
(Original drawings by M. H. Muma.) it is particularly
heavy infestations on spring foliage, especially during dry
The other type of injury is a more severe one that results
in leaf drop, which usually occurs any time from October through
February. Sometimes the leaves die on the twigs and if such
Fig. 45.-Two trash bug larvae are shown along with a pupa case
(left). The actual larvae do not show, but the trash which has been
collected on their back is shown. This trash is composed of the skeletons
of their victims. (Enlarged.)
Insects and Mites Found on Florida Citrus 49
injury occurs during the period from October through Decem-
ber the twigs usually die. At other times there may be a general
leaf drop when most of the leaves are heavily infested. Either
type of leaf drop should be avoided by controlling the mites
before a heavy infestation develops.
Several predators feed upon eggs and
other stages of purple mites (16). Among
the lacewings are the trashbug, Chrysopa
lateralis Guer., and an aphid lion, C. inter-
rupta Schneid. Two ladybeetles also feed
on these mites (16, 29). The Southern two-
spotted ladybeetle, Olla abdominalis var.
plagiata Csy., as an adult is very similar
in appearance to, but larger than, the twice- Fig. 46.-Larva of
stabbed ladybeetle. It may be differentiated a lacewing fly. The
by the fact that the spots are more yellow long, slender jaws are
hollow. They are
and larger than in the twice-stabbed beetle. punched into the mite
Also, there is a prominent white marking or egg and serve as
straws for the larva
on the very front end of the beetle. The to suck out the con-
second ladybeetle, Stethorus utilis (Horn), tents of its victim.
feeds readily on this mite. This is a very
tiny black beetle and is rarely noticed because of its small size.
The six-spotted mite, Eotetranychus sexmaculatus Riley, has
long been a pest of Florida citrus. It is straw colored and as
Fig. 47.-Six-spotted mites, male left, female right. The mites are a
clear straw color, with dark spots on the back. (Original drawing by
M. H. Muma.)
50 Florida Agricultural Experiment Stations
an adult usually has six spots on the sides of its back. On the
young the spots are irregular and sometimes absent. This mite
is most prevalent from February through May.
Fig. 48.-Leaves distorted and splotched by the feeding of six-spotted mites.
Note light-colored areas along the midrib. These are yellow.
Six-spotted mites may be found on old foliage during winter,
and new leaves become infested as they appear in the spring.
If present in large numbers the mites may cause the young
leaves to fall before they attain a normal size. Usually, how-
ever, they distort the new growth and leaf drop occurs several
The mites first attack the under side of the leaf along the
midrib and about the petiole. As the infestation increases they
spread out over the under side of the leaf and cause yellow,
cupped areas to form. A tree with typical six-spotted mite
injury will display crinkled leaves with large yellow splotches,
and if the infestation is heavy, a leaf drop occurs.
Insects and Mites Found on Florida Citrus 51
During the fall and winter six-spotted mites are occasion-
ally seen on old foliage, often in conjunction with masses of pur-
ple scales. The reason for this relationship is unknown.
Several predators feed on six-spotted mites. Possibly the
most important are two mite species noted by Muma (31),
Typhlodromus floridanus Muma and T. conspicuous Garman. In
addition, the ladybeetle, Stethorus utilis (Horn), and the thrips,
Scolothrips sexmaculatus (Perg.), are important predators.
Stethorus has a very short life cycle of only two weeks (33).
TEXAS CITRUS MITE
The Texas citrus mite, Eutetranychus banksi (McG.), is a
recent addition to injurious mites which are present on citrus
in Florida (35). This species has been collected also on velvet
beans and castor beans near Orlando and from chinaberry trees
In appearance and habit this species is very similar to the
purple mite. Eggs are laid along the midrib and the mites
prefer the top side of the leaves on the sunny side of the tree.
Adult females are a little larger than the female of the purple
mite. They vary in color from tan to brownish-green, with
Fig. 49.-Texas citrus mite; male (left) and female (right). These
are tan to brownish green in color, but smaller than the purple mite.
(Original drawing by M. H. Muma.)
52 Florida Agricultural Experiment Stations
spots and bars near the lateral margin of the body. Males are
smaller than the female and the body is triangular in shape.
Injury to foliage is similar to that of the purple mite and
this species is undoubtedly confused with the purple mite by
growers in the field.
The broad mite, Hemitarsonemus latus (Bke.), has been re-
ported recently in citrus in Florida (30). The females are rather
broad or oval in shape and pale green in color, with a longitudinal
stripe that is forked at each end. According to Muma (30),
feeding by this mite is confined to young fruit up to 1.5 inches
in diameter and to immature foliage. The injury to fruit is
commonly called "sharkskin", and the margins of the leaves
are rolled and cupped. At present knowledge of this mite and
the extent of injury it causes is limited.
CONTROL OF SPIDER MITES
Red spider mites may be controlled by several different miti-
cides (52). Many new miticides are being tested, so that the
Spray and Dust Schedule of the
Better Fruit Program should
always be consulted.
A very effective control of
purple mites has been obtained
--by preventing infestations. If
Materials were applied by early
"- November and then again before
spring growth, purple mites
/ caused little injury. New miti-
Scides may eliminate the second
spray. Dusts are less effective
Six-spotted mites present a
different problem as regards
timing and coverage. A dor-
mant miticide applied in Jan-
uary or before spring growth
will usually prevent six-spotted
Fig. 50.-The six-spotted thrips, mite infestations in the spring
a predator of six-spotted mites. flush of growth. However, it is
(Original drawing by M. H.
Muma.) necessary to make a thorough
Insects and Mites Found on Florida Citrus 53
spray application with emphasis on covering the under side of
FALSE SPIDER MITES
Two species of false spider mites, Brevipalpus australis
(Tucker) and B. phoenicis (Geijskes), have now been recorded
on citrus in Florida. Although smaller, these are very similar
in appearance to the true red spiders and are probably confused
with them. The latter species has been reported from most of
the citrus growing areas of the state, while B. australis appears
to be confined primarily to the upper east coast.
Fig. 51.-Twigs, foliage and fruit showing typical lesions of leprosis.
(Photo by L. C. Knorr.)
B. australis is of interest because of its association with the
disease, leprosis. This condition was called scaly bark in the
years from 1917 through 1925 when it was fairly common.
Studies reported by Knorr and DuCharme (19) in 1950 showed
that scaly bark was the same disease as lepra explosive of the
Argentine. They suggested that the term leprosis be used.
The disease is characterized by lesions on fruit, leaves and
twigs (Fig. 51). It is found only in a few unsprayed groves
at present. Whether the mite transmits a virus or whether it
54 Florida Agricultural Experiment Stations
secretes a toxin has not been determined. Thompson (50) re-
ported that leprosis was controlled by controlling the mite.
MEDITERRANEAN FRUIT FLY
Mediterranean fruit fly, Ceratitis capitata (Wied.), was first
reported in Florida in April 1929. A vigorous campaign of
eradication was successful. Again in April 1956 new infesta-
tions of the fly were found near the Miami International Airport.
Subsequent survey work showed infestations as far north as
central Florida. The Florida State Plant Board and United
States Department of Agriculture's Plant Pest Control Branch
are prosecuting a successful eradication program as this is be-
Mature soft fruits are the preferred place for oviposition.
Generally, grapefruit are preferred to oranges, but calamondin
and kumquat were two of the common citrus host plants in the
1956 outbreak. Other fruits such as peach, guava, surinam
cherry, mango, and rose apple also were infested.
The adult fly is smaller than the housefly (Plate V). It is
characterized by dark bands on the wings, a yellowish abdomen
Fig. 52.-Nearly mature larvae or maggots of the Mediterranean fruit
fly (left) measure up to about % inch in length. They are found inside
the fruit. The pupa cases on the right are found in the soil. (State Plant
Insects and Mites Found on Florida Citrus 55
with two white stripes on the top side, and a black thorax with
white markings. The wings are held in a drooping position
when the fly is at rest.
The larvae or maggots measure about %/8 inch in length
when full grown, and at this stage of development they can
jump several inches. This characteristic is a rough means of
Control of adult flies is effected by the use of bait sprays
containing an attractant and an insecticide. Infested fruit can
be successfully fumigated with ethylene dibromide.
The life cycle is a relatively simple one. The female punc-
tures the rind of the fruit with her ovipositor and deposits the
eggs immediately under the surface of the peel. Usually several
eggs are laid in one puncture and there may be as many as 25
or 30 maggots developing in a single fruit. The eggs hatch in
one to three days and the maggots begin to feed on the fleshy
portion of the fruit. They will complete their development in
from 10 to 14 days under normal summer conditions. By that
time the fruit will usually have dropped to the ground. The
larva cuts a hole through the peel to the outside. This hole
is usually present before the fruit drops. The larva makes its
way outside the fruit through this hole and crawls out or drops
to the ground. It burrows a short distance into the soil, usually
about 1/2 inch. Here, it undergoes pupation, during which time
wings are formed. The fly emerges from the soil, feeds on
nectar and honeydew for several days and reaches sexual ma-
turity after approximately a week. After copulation and fertil-
ization have taken place, the female fly begins to lay eggs. She
may lay several hundred during the course of her life span. It
has been demonstrated that fertilization by the male is a con-
tinuing process and that for maximum oviposition potentials
to be realized there must be repeated copulation taking place.
The entire life cycle takes approximately three weeks to 30 days
in summer. It may be prolonged during winter months.
INSECTS OF MINOR IMPORTANCE
Although aphids or plant lice were considered to be major
insect pests during the 1920's, they are now of minor importance.
Aphid control may well become a more important factor in citrus
56 Florida Agricultural Experiment Stations
production due to the discovery of the tristeza virus (11) in
Florida. Tristeza, or quick decline as it is called in California,
has been shown to be transmitted by a black aphid, Aphis citri-
cidus (Kirk.), in South America (1). This species is found in
most citrus-producing areas of the world but has never been
taken in the United States. Norman and Grant (36) have
found that the green citrus aphid, Aphis spiraecola Patch., is
capable of transmitting the tristeza virus in Florida. Under
California conditions Dickson et al. (3) showed that the primary
insect vector of the quick decline virus was the melon aphid,
Aphis gossypii Glov. These are the common species on citrus
in Florida, and their control on trees on sour orange rootstock
may be of considerable economic importance.
Fig. 53.-Left: A colony of green citrus aphids on citrus leaf. The
white skeleton-like objects are cast skins or molts. (Enlarged.) Right:
Curled leaves caused by the feeding of green citrus aphids when the leaves
were young. Injury is often more severe than that shown.
Insects and Mites Found on Florida Citrus 57
Aphids belong to the order Homoptera and the family
Aphidae. Three species are commonly found on citrus in Flor-
ida. All are small, about 1/16 inch in length, and are found
in colonies on young growth. The spirea or green citrus aphid,
Aphis spiraecola Patch., is the most common. It is followed by
the melon aphid, Aphis gossypii Glov., and the black citrus aphid,
Toxoptera .aurantii (Fonsc.). The latter species is rarely if
ever a commercial problem. The green peach aphid, Myzus
persicae (Sulz.), also has been found on citrus, but it has never
been an economic factor.
Aphids undergo a complex and peculiar life cycle. Most
aphids are born alive and are produced without fertilization by
the male. When citrus foliage is tender the young do not de-
velop wings as they mature but later, as the foliage hardens,
winged forms are produced. These are females which fly to
another tree and start new infestations. Males are produced
only during the fall and winter months.
The injury caused is the result of aphids feeding on young
tender growth. Leaf buds are susceptible to injury as soon
as they unfold and the younger the leaves at time of infesta-
tion the more severe the injury. Aphid feeding causes the
leaves to be curled and twisted. This distortion remains as long
as the leaf stays on the tree. When infestations are severe, an
entire growth flush may be ruined. The curled leaves are in-
efficient and the distortion and accompanying sooty mold serve
as a breeding ground for scale insects.
Aphid injury is usually severe only during the period of
spring growth. Varieties such as Temple and tangerine, which
start growth later in the season, are most susceptible. This is
probably the result of aphid build-up on other varieties, and as
only a relatively small amount of young foliage remains, the
aphids concentrate on the few varieties which are still growing.
Occasionally injury may be severe in young groves during the
Aphid infestations on young bloom buds can cause a bud
drop so severe that yields may be, affected. However, the major
consideration is the reduction in the number of normal leaves
on the tree. As noted above, winged forms are produced as
foliage hardens or as excess crowding develops. This results in
dispersal of the aphids to other trees with tender foliage. When
infestations are not noted until winged forms are already being
produced in large numbers, artificial control is of little value.
58 Florida Agricultural Experiment Stations
Numerous natural enemies reduce the aphid hazard on citrus.
A species of fungus, Entomophthora fresenii Nowakowski, com-
monly attacks aphids when weather conditions are favorable.
The syrphid fly larvae, Baccha fascipennis Say and Baccha
clavata (F.), both feed on plant lice. Aphidius testaceipes
(Cress.) is a parasite of aphids (28).
Ladybeetle predators are the most conspicuous aphid enemies.
Five species are primary predators, the blood-red ladybeetle,
Cycloneda sanguinea (L.), being the most common. Adults are
about 3/ inch long and are predominantly reddish-orange. The
larvae are black with spots and bars of red and white (25).
The adult convergent ladybeetle, Hippodamia convergens
Guer., is about the same size as the blood-red beetle, but this
beetle is more elongate and oval than circular. The head and
thorax are black margined with white, while the wings are red
with seven black spots on each side (25).
Two species belonging to another genus are the collared
ladybeetle, Scymnus collaris Melsh., and the white-tailed lady-
beetle, S. partitus Csy. These beetles are very tiny. The former
is brown to black, with the head, most of the thorax, and the
hind tips of the wings light yellow to orange. The latter species
has somewhat similar coloration.
The chinese ladybeetle, Harmonia dimitata 15-spilota Hope,
is an extremely large ladybeetle. Adults are about 1/3 inch long.
They are orange-red to red, with black spots on the thorax and
Fig. 54.-Ladybeetles that feed on aphids. Left to righ: (upper),
the collared ladybeetle, Scymnus collaris; (lower), the white-tailed lady,
beetle, Scymnus partitus; the convergent ladybeetle, Hippodamia con-
vergens; the blood-red ladybeetle, Cycloneda sanguinea; and the chinese
ladybeetle, Harmonia dimitata 15-spilota. These measure 1/16, 1/12, 1/4 to
3/8, 1/4 to 3/8, and 1/3 inch in length, respectively. (Original drawings by
M. H. Muma.)
*W ~ ~ Lrl r-v
Insects and Mites Found on Florida Citrus 59
wing covers. This beetle was introduced into Florida from
California in 1925. It is most common in Orange, Lake and
Osceola counties (25).
GREEN CITRUS APHID
The species, Aphis spiraecola Patch., is the common one found
on citrus in Florida. It was apparently first noted on citrus in
Manatee County in 1922 and became a serious pest during 1924
and 1925 (21). It is probable that its native host plant is
Spiraea. It was only on this plant that Tissot (44) reported
finding viable eggs. No eggs were noted on citrus (21). The
approved common name for this insect is the Spirea aphid, al-
though in Florida it is known as the green citrus aphid. In 1953
(36) it was shown to be a vector of tristeza virus.
This aphid is readily distinguished from the melon aphid. It
is pale green in color and appears to be almost the same color
as the young citrus leaves upon which it is feeding. As wing
pads form, the thorax darkens and becomes brown but the abdo-
men remains green (58).
The species Aphis gossypii Glov. is less common than the
green citrus aphid but is found in most groves and has attained
a new importance with the discovery in Florida of the tristeza
virus of which it is a vector. Its life cycle has been thoroughly
described by Goff and Tissot (10). Apparently, in Florida, re-
production is parthenogenetic-offspring are produced without
males having been present.
While this species may be somewhat green in color, it is
never so pure a green as to closely resemble the green citrus
aphid. It varies in color from a light yellowish green to a dark,
slate-blue green, and on occasion is even darker (10).
BLACK CITRUS APHID
Toxoptera aurantii (Fonsc.) is very dark brown in color.
It is of economic importance only on rare occasions and then
almost exclusively on grapefruit. It is most commonly found
on grapefruit in little colonies on the under side of nearly full-
sized leaves. Although this aphid is of a dark color, it is not
the same species as the black aphid, Aphis citricidus (Kirk.),
which is a very efficient transmitter of tristeza in South America.
As with most aphids, it may be noted that periodically the
60 Florida Agricultural Experiment Stations
entire colony seems to stand on their heads. It was first noted
in 1947 by James Turnbull, an irrigation engineer at the Florida
Citrus Experiment Station, that when the black citrus aphids
stood on their heads they emitted a rasping, scratchy sound.
The authors checked on this and found it to be true. They were
never able to find an audible sound coming from other species.
This phenomenon may be observed by placing the ear close to
the leaf on which the aphids are found and listening carefully.
Aphid control is usually attempted only in young groves or
in Temple orange blocks. Other mature trees are rarely affected
sufficiently to justify control measures. In order to be effective,
the application must be properly timed, and repeated sprays
are often necessary. The fact that reinfestation may occur
within a few days after the spray is a complicating situation.
As the leaves mature, and the aphids grow wings and fly, an
infestation may disappear with no spray being used. Therefore,
it is necessary to spray
shortly after aphids appear
on tender growth. Once
leaves have begun to harden,
questionable. See the Spray
and Dust Schedule of the
Better Fruit Program for
current aphid control recom-
/ PLANT BUGS
Several species of true
S1 bugs (suborder Heteroptera,
order Hemiptera) are oc-
casionally serious pests on
Fig. 55.-The leaf-footed or citron
plant bug, Leptoglossus gonagra. One citrus. Others are com-
is a winged adult and the other a well- only found on citrus but
developed nymph. The white line across
the thorax just behind the head does have not been shown to
not show in this picture. This char- produce economic damage.
acter differentiates this species from Growers have been prone to
L. phyllopus. Growers have been prone to
call any and all of these bugs
"pumpkin bugs," in spite of the fact that the term includes bugs
from more than one family. All of these insects have long,
Insects and Mites Found on Florida Citrus 61
piercing, sucking mouth parts which can penetrate completely
through the peel of the fruit.
These insects feed on fruit and cause it to drop. While this
may be severe in a single grove, it is seldom general over a wide
area. The insects move into mature and nearly mature fruit
from cover crops in the grove or out of adjacent fields, particu-
larly when the ground cover is beginning to dry up or harden.
Old watermelon fields and leguminous cover crops are important
places of origin. Injury is most common on tangerines and
early oranges and almost always occurs between September 1
and late November. The authors have seen injury so severe
that 100 percent of the fruit was lost in areas larger than an
acre in size. The insects may start at one margin of the grove
and move across it, feeding on and causing the fruit to drop.
On other occasions, when they are feeding on both the cover
crop and the fruit, the losses may be less spectacular but never-
theless represent a
sizable portion of the
In recent years
the most severe in- .
jury has been caused
by the two leaf-
footed plant bugs,
Leptoglossus gonagra 1
(Fab.) and L. phyllo-
pus (L.). The former
is characterized by a Fig. 56.-The leaf-footed plant bug, Lepto-
white line runninglosss ngphylos. Note the white band across
white line running the wings.
across the prothorax
in front of the wings. L. phyllopus has a wider band, but this
is located across the wings. L. gonagra is the more common
and has been called the citron bug (48) because of the fact that
it commonly builds up on melon-like citrons in groves or in old
watermelon fields. In recent years this species has caused more
severe damage than any of the others described in this section.
Acanthocephala femorata (Fab.) is a larger, more robust
individual than the two mentioned above. It is occasionally
found on citrus but does not appear to be of economic import-
ance. Anasa scorbutica (Fab.) and Alcaeorrhynchus grandis
(Dallas) have also been collected on citrus.
Euthochtha galeator (Fab.) is another member of the family
62 Florida Agricultural Experiment Stations
Coreidae which has been collected on citrus and which causes
a peculiar type of injury. In the spring it feeds on the tender,
succulent twigs and causes them to wilt and die. The authors
have noted this type of damage on as high as 25 percent of the
trees in a small block. Only one shoot may
be affected, but it will be brown and dry on
Sthe tip and m ay have died back as m uch
as six inches.
The cotton stainer, Dysdercus suturellus
(H.-S.), was a pest on citrus many years
ago when cotton fields were adjacent to
citrus. As a mature bug, it is dark red
and about 1/2 inch long. The wings are
dark brown and edged with yellow. Since
cotton is again being planted in some
.citrus sections of Florida, it is possible
"that this insect may become a pest in some
Several species of stink bugs (family
Pentatomidae) are found on citrus and
several of these have been recorded as caus-
ing fruit drop. During the time when
crotalaria was a major cover crop, the
Fig. 57.-Acantho- Southern green stink bug, Nezara viridula
(Fab.) above, and (L.), was a major pest. Another fairly
Anasa scorbutica be- common stink bug is Euschistus servus
found on Scit nay (Say). This insect is brown in color and
almost the same size as the green stink
bug. Both species have been noted in recent years to build up
on hairy indigo and to drop considerable fruit when the cover
crop is not chopped until late November.
Numerous other stink bugs have been recorded on citrus.
These are rarely if ever pests, but on occasion may feed on fruit
and cause it to drop. The following species are pictured here:
Apateticus cynicus (Say), Brochymena florida Ruckes, Euschi-
stus obscurus (P. deB.), Podisus maculiventris (Say), P. sagitta
(Fab.), Proxys punctulatus (P. deB.), and Solubea pugnax
Control of Plant Bugs.-Usually, damage by plant bugs and
stink bugs may be avoided by proper cover crop management.
In most cases they build up on leguminous cover crops in the
grove itself. When they are expected to be a problem, the cover
Insects and Mites Found on Florida Citrus 63
crops should be chopped and disked in September. Green fruit
is less susceptible than mature fruit and the flying forms will
usually move from a grove if their food source is destroyed.
Fields containing watermelons, hairy indigo, crotalaria, vel-
vet beans, etc., should be examined and if infestations of bugs
are found in September in fields adjacent to early oranges or
tangerines, the fields should be thoroughly cultivated. Consult
the Spray and Dust Schedule of the Better Fruit Program for
specific control recommendations.
Fig. 58.-Several species of stink bug collected on citrus.
Left to right, top row: Euchistus servus (Say), Apateticus
cynicus (Say), Brachymena florida Reekes, and E. obscurus
(P. deB.); bottom row: Podisus maculiventris (Say), P.
sagitta (Fab.), Proxys punctulatus (P. deB.), and Solubrea
pugnax (Fab.). (All actual size.)
Thrips injury on citrus is of minor importance. At one
time the Florida flower thrips, Frankliniella cephalica bispinosa
(Morgan), was considered to be a major cause of scars on
oranges (58). In 1940, Thompson (47) reported that thrips
injury was actually wind-scarring and had no relationship to
thrips infestation. He did note a small amount of injury at the
stylar end which was apparently produced by this species (Fig.
60). This scarring is similar to but much less severe than a
condition now known as stylar end russeting, the cause of which
The Florida flower thrips is barely visible to the naked eye
and varies in color from light yellow to almost orange. It may
64 Florida Agricultural Experiment Stations
be found in abundance on most blossoms, as the bloom is almost
always infested. Although Watson (56) believed that this
species could cause drop of bloom and tiny fruit and that this
could be a major factor
in failure to set a good
crop, no substantiating
data have even been pre-
sented. In 1951 Frank-
liniella cephalica was
found in a mixed popula-
tion with Leptothrips sp.
on grapefruit trees near
Kathleen. These thrips
were causing a distortion
ln of spring flush growth.
,. The orchid thrips
-. (Moulton), was found by
"Thompson (47). In 1937
Fig. 59.-Wind scar on an orange. This he first recorded it from
injury was formerly believed to be caused
by flower thrips. a grove on Merritt Is-
land. It is apparently
found throughout the Florida citrus area, although it is most
common along the east coast. The adults are yellowish in color
and the wings, when folded, give the appearance of two black
lines down the back. The
.. young nymphs are color-
.less, but as they grow
.. older they take on a yel-
lowish cast, and on older
nymphs the abdomen is
definitely pink. These
insects actively a v o i d
sunshine. They are most
commonly found feeding
on fruit at the point
where two fruit, or a
leaf and fruit, are in
The injury caused by
these insects is char-
Fig. 60.-Injury apparently caused by
flower thrips. acteristic, but in some
Insects and Mites Found on Florida Citrus 65
respects resembles rust mite injury. On mature fruit, injury
which occurs early in the fruit development appears as a silvery
patch on grapefruit and as a rough brownish blotch on oranges.
The scar essentially resembles one caused by early rust mite in-
jury. The shape of the injury shown in Fig. 61 is typical of
early thrips injury. Late injury usually appears as a ring on
the fruit at the point where two fruit have been pressed together.
The ring is quite characteristic, but the surface of the scar
itself is virtually identical with late rust mite injury.
The greenhouse thrips, Heliothrips haemorrhoidalis (Bouch6),
has been collected on citrus on the Florida east coast (47).
At present there appears to be little need for thrips control.
Only the orchid thrips does damage which could be considered
as potentially economic, and it is normally controlled by sprays
that control rust mites.
Two species of termites have been recorded as doing damage
to citrus in Florida. The most common injury is the partial
girdling or outright killing of young trees by a subterranean
form, Reticulitermes flavipes (Kollar). Growers commonly re-
fer to these insects as white ants or wood lice. Actually they
have no relationship to either ants or lice. While more than
one species of termite may be involved, only one has been re-
corded (58) as doing this type of damage.
Fig. 61.-Orchid thrips injury. The late injury on the fruit is at the
point where two fruit hung side by side and touched. Early injury is
shown on the right and late injury on the left. Note that early injury is
cracked and similar to early red mite injury in appearance.
66 Florida Agricultural Experiment Stations
This injury is most often found in young groves which have
been set on newly cleared land. Wood debris seems to serve
as a source of infestation. The injury ordinarily occurs during
the period when the trees are banked in the winter months and
during the first year or two after the grove has been set. The
termites may completely girdle the trunk near the bud union,
and the first symptoms will be a paling of the foliage accom-
panied by yellow veins. Prompt action will often save the tree.
Removal of the bank may be sufficient to destroy the colony
and to let the trunk of the tree dry out and heal over. If ter-
mites are present, they will be found as white, ant-like creatures
working around the lesions on the tree and in the adjacent
soil. They are about the size of a medium-sized ant, but have
a thick waist in contrast to the wasp-like waist of the ant.
Prevention of this injury is more important than cure. Clean,
dry soil, free from wood debris, should be used to make the bank.
Fig. 62.--Roots hollowed out by the dry wood termite.
Insects and Mites Found on Florida Citrus 67
A handful of the proper insecticide worked into the bank ad-
jacent to the tree is an excellent means of preventing injury.
Consult the Spray and Dust Schedule of the Better Fruit Pro-
gram for latest chemical control recommendations.
A dry wood termite, Neotermes castaneus (Burm.), was re-
ported as a citrus pest by Thompson (45) in 1933. This termite
lives in the trunk, large limbs and roots of mature citrus trees.
It has been observed to hollow out roots as much as nine feet
away from the crown and to extend these tunnels into all the
main limbs (Fig. 62). Roots with diameters of only 3/16 inch
have been hollowed out. In one instance a trunk with a 612-
inch diameter had a cavity five inches across. The termites
also may eat through roots; these wounds may serve as a source
of fungus infection.
Trees affected by this termite often show a general decline.
Where the termites have tunneled near the surface of the trunk
or limbs, splitting of the bark and gumming will result. A drill
hole at this point will show the limb or trunk to be hollow.
This type of injury appears to have been more common 20 years
ago than at the present time.
Numerous species of ants, most commonly associated with
insects that secrete honeydew, may be found in citrus groves.
However, several species are harmful to trees. Miller (21)
listed the following species as being associated with citrus
aphids: Solenopsis geminata (Fab.), Camponotus abdominalis
floridanus (Buckley), Camponotus socius Roger, and Dorymyr-
mex pyramicus var. flavus McCook. DeBach (2) found that the
Argentine ant, Iridomyrmex humilis Mayr, reduced natural
enemies of California red scale in California. No such effect
has been demonstrated by ants in Florida.
A leaf cutting ant, Pogonomyrmex badius (Latr.), is one of
the destructive species, especially on young trees planted on
recently cleared land. This ant is medium-sized, dull reddish-
brown, and larger than the more common red or black species
of ants found in groves. A colony forms a crescent-shaped
mount about the entrance of its burrow. The color of the cres-
cent is due to the coloration of the subsoil brought up by the
ants. When clay is near the surface, it will be the material
from which the crescent is formed. This ant cuts small pieces
from the leaves and carries them to its nest. While not particu-
68 Florida Agricultural Experiment Stations
larly destructive to large trees, they can cause young trees to
die by defoliating each flush of growth as it appears.
The fire ant, Solenopsis geminata (Fab.), is a small, pale
yellowish or reddish ant that also can be destructive to young
trees and top-worked trees. They feed on the leaves and young
twigs, causing them to die.
Another small, light reddish ant, Dorymyrmex pyramicus
var. flavus McCook, is commonly found on citrus trees, especially
when honeydew is present.
A small black ant will also feed on the bark of top-worked
and small nursery trees.
A fourth species, Camponotus abdominalis floridanus (Buck-
ley), is a large reddish insect which is commonly called a "bull
ant." These are often found at the base of the tree, especially
when there is a rotten area, and seem to live between the roots.
They probably do no harm and may even be beneficial by remov-
ing dead and decaying wood.
All species mentioned here are readily controlled with in-
secticides. Sprays or dusts may be applied to the tree or to the
ant hills. Periodic retreatment is necessary, but ants can be
satisfactorily controlled if the owner feels it is important.
On occasion the little fire ant, Wasmannia auropunctata
(Roger), may be a severe pest, particularly along the east coast.
This insect does no damage to the tree, but its bite is so severe
that the presence of these ants may prevent grove labor from
working in, or near, the trees. This problem is encountered
in picking and pruning operations. The ant is small and red,
with a bite that leaves no doubt as to its identity. Large colonies
of these ants may be observed on almost every tree in a grove
and they must be destroyed if normal grove operations are to be
maintained. Osborn (37, 38) has shown that the little fire ant
may be controlled with insecticides. See Spray and Dust Sched-
ule of Better Fruit Program for further details.
Members of the order Coleoptera occasionally damage citrus
but generally are of little economic importance.
The weevil-like beetles are the major coleopterous pests of
citrus in Florida. Injuries caused by the several species are
Insects and Mites Found on Florida Citrus 69
Fuller's rose beetle, Pantomorus godmani (Crotch.), is a
greyish brown weevil which measures about 1/3 inch in length.
The adults feed along the margins of the leaves, producing a
characteristic notched effect.
These feeding indentations
may extend almost to the
midrib, but usually are con-
fined to the margin of the
The adult probably lays
eggs in crevices on the bark
or twigs and after hatch-
ing, the larvae drop to the
ground. Here they feed on
roots of the cover crop or
"citrus tree. Damage is rare-
ly severe enough to require
control measures. However,
in 1950 and 1951, W. T.
Long (unpublished report)
observed relatively severe
injury to roots as well as
foliage in the Ft. Pierce-
Vero Beach area.
The leaf notcher, Artipus
floridanus Horn, is about 2/3
the size of Fuller's rose
beetle and is light grey in
color. The life cycle of this
insect is unknown, but it is
probably similar to that of
Fuller's rose beetle. Injury
from the adult is a series of
fine serrations or notches
along the leaf margins; Fig. 63.-Above: Fuller's rose weevil
(natural size). Below: Roots showing
these are usually quite shal- injury and scar tissue formed after
low, and smaller than those attack by larvae of Fuller's rose weevil.
(Photos by W. T. Long.)
made by Fuller's rose beetle.
Injury from this insect has been noted most commonly on the
Florida east coast. No cases of injury seen by the authors have
been severe enough to require control.
The citrus root weevil, Pachnaeus litus (Germar), is present
70 Florida Agricultural Experiment Stations
Fig. 64.-Foliage with typical serrated edges produced by the feeding of
adults of Fuller's rose weevil. (Photo by W. T. Long.)
in Florida but its range is largely confined to the lower east
coast. It has rarely been taken in central Florida. It was re-
ported by Wolfenbarger (59) in both orange and Tahiti lime
groves in the Homestead area. In 1951, damage was more
severe than it had been for a number of years (59). It feeds
on roots as a larva (Fig. 66) and
damages fruit and leaves as an
adult. The feeding pattern on
foliage is similar to that of
Fuller's rose beetle, but the
leaves are more nearly consumed
and holes are eaten also in the
center of the leaves. In some
respects the feeding resembles
that of katydid injury. The
Fig. 65.-Adult of the leaf notch- citrus root weevil is about 1/2
er, Artipus floridanus. These are inch long, has a short, thick
light grey and measure about 1/4
inch long. snout, and is blue-green in color.
Insects and Mites Found on Florida Citrus 71
Fig. 66.-Citrus root weevil, Pachneus litus, and its injury to foliage.
The beetle is blue-green and the females are about 5/ inch long. (Photo
by D. O. Wolfenbarger.)
Fig. 67.-Injured roots following feeding by citrus root weevil.
(Photo by D. O. Wolfenbarger.)
72 Florida Agricultural Experiment Stations
P. opalus (Oliv.), a closely related species, has been found on
numerous occasions in various parts of the state and is prob-
ably common in central Florida. It causes damage similar to
that described above.
Very little work has been done on the chemical control of
these species. Wolfenbarger (59) did not get satisfactory con-
trol of the citrus root weevil with parathion or cryolite. Cryo-
lite has been used successfully on Fuller's rose weevil and it is
possible that several of the newer organic insecticides would
Watson (58) reported that June beetles occasionally did
considerable damage to citrus. These depredations were appar-
ently recorded during the 1920's and no such injury has been
reported during the last two decades. Watson did not identify
the species involved.
Several species of small beetles occasionally make tunnels
in dying or dead wood. These have commonly been referred
to as shot-hole borers. Platypus compositus Say (family Scoly-
tidae) and Bitoma carinata (Lec.) (family Tenebrionidae) were
collected by the authors from one orange tree near DeLand in
1947. Several other species are undoubtedly involved on occa-
sion. These insects are not primary pests and invade only trees
weakened from some other cause, such as lightning or water
GRASSHOPPERS AND RELATED INSECTS
Grasshoppers are occasional marauders of citrus groves.
Since the authors (17) have thoroughly discussed this problem
elsewhere, only the two most common pest grasshoppers will
be mentioned here.
The species Schistocerca americana americana (Drury), some-
times called the bird grasshopper, is the only grasshopper which
has ever presented a really serious threat to citrus growers
over a large area. From the fall of 1946 through the spring
of 1949, the insect was common throughout groves in areas
about Plant City and between Lakeland and Wauchula. During
that period an occasional young grove was almost completely
Insects and Mites Found on Florida Citrus 73
defoliated and older groves were severely damaged. The typical
habitat was afforded by old vegetable fields and citrus groves.
Nearly full-grown nymphs cause the most damage. Very
young individuals do little feeding on citrus and the winged
adults do not appear to have large appetites. This and other
species will occasionally cause damage by feeding on the newly
set fruits. This damage is identical with what is commonly
called katydid injury (Fig. 77).
Fig. 68.-Adult (female left, male right) of the American or bird grass-
hopper, Schistocerca americana (Drury).
The bird grasshopper passes the winter in the adult stage
and has two generations per year. The first generation hatches
and matures between March and June; the second hatches in
late summer and often arouses the grower's anxiety in the fall.
Actually, these flying forms do little damage. They like the
trees to roost in but prefer other vegetation as food. They can
usually be driven from a grove by clean cultivation.
EASTERN LUBBER GRASSHOPPER
The Eastern lubber grasshopper, Romalea microptera
(Beauv.), is common in many citrus groves during spring and
summer months, being most plentiful in groves adjacent to low,
marshy land. During the summer literally thousands of these
grasshoppers may be seen sunning themselves on the roads be-
tween the Ridge Section and the Florida East Coast.
Lubbers overwinter in the egg stage and hatching usually
begins early in February. The nymphs are almost solid black
with yellow and occasional red markings. These are the grass-
hoppers which are commonly found feeding on amaryllis and
dooryard shrubbery in the spring. The nymphs pass through
five instars before attaining adulthood; they reach maturity
during May and June in most years. Although adults have
Fig. 69.-Various stages in the life cycle of the Florida lubber grass-
hopper. Top to bottom: first and second instars; second and third instars;
third and fourth instars; fifth instar; and adult female. As nymphs these
are black with yellow or red markings. As adults they are a brilliant
yellow with red and black markings.
Insects and Mites Found on Florida Citrus 75
Fig. 70.-Male and female adults of the red-legged grasshopper, Melano-
plus femur-rubrum propinquus (Scudder).
/ /i.t i''i [".'1 '! "
_* I-. It I
Fig. 71.-Adults of the genus Paroxya. Left, male of P. atlantica atlantica.
Right, female of P. clavuliger.
Fig. 72.-Adults of Schistocerca obscura. Female left, male right. The
body of this grasshopper is green, the wings brown.
wings, they are incapable of flight. Copulation may be noted
in late June and oviposition follows. These eggs do not hatch
until the following spring and thus they complete only one
generation per year.
Lubber grasshoppers rarely damage citrus. Nymphs have
been observed feeding on young trees and in some instances
have completely defoliated newly set citrus trees; however, they
76 Florida Agricultural Experiment Stations
do not materially affect large trees. They are slow and sluggish
in their movements and apparently not particularly voracious.
In spite of the large size of these grasshoppers, they do not con-
sume large amounts of leaf
Chemical control is prac-
tical, although dosage is rela-
". tively heavy as compared
with that necessary in other
parts of the United States
Fig. 73.-Adult female of the species parts of the United States
Arphia granulata Sauss. The mark- because these two species
ings on this grasshopper are striking are exceptionally large. Com-
and the legs are usually colored. plete details on control may
be found in Florida Agricultural Experiment Station Bulletin 496
or in the Spray and Dust Schedule of the Better Fruit Program.
It was found that clean cultivation from February through
May was generally effective against the bird grasshoppers as
a means of preventing oviposition and the subsequent hatching
of young. Clean cultivation, started in mid-August, prevented
most of the second generation injury. Chemical control was
necessary only in small areas in the grove, or when invasions
occurred from adjacent fields.
The lubber grasshopper migrates into the edges of many
groves adjacent to marshes, and may seriously damage any
young trees present. Control measures under these circum-
stances are not too satisfactory. Insecticides may be used to
kill the hoppers, but unless the grasslands are thoroughly treated
also, a reinvasion is likely.
Katydids are commonly seen in citrus groves. The broad-
winged katydid, Microcentrum rhombifolium (Sauss.), lays its
eggs along the margin of the leaf (Fig. 75). These eggs are
often parasitized by Anastatus mirabilis (Walsh & Riley) and
small, round emergence holes may be seen (Fig. 75). The broad-
winged katydid has several generations per year (13). Almost
all stages can be found at any time during the year, but a general
hatch appears to occur at approximately the same time as spring
Although at least two other species of katydids (Fig. 74)
are sometimes found on citrus, only the broad-winged katydid
Insects and Mites Found on Florida Citrus 77
is of any economic importance. Occasionally, on young trees,
the broad-winged katydid causes severe defoliation. The young
from a single group of eggs on one leaf may be enough to seri-
ously damage a young tree. A second type of injury, produced
when katydids feed on young fruit, also may be caused by several
other species of insects and it is impossible to tell which was
actually the cause. This injury (Figs. 76 and 77) is usually
referred to as katydid injury, however.
Fig. 74.-Above: Two species of katydid occa-
sionally found on citrus-Neoconocephalus triops
above and Scudderia sp. below. Bottom: The broad-
winged katydid, the species commonly found in citrus
Katydids may be controlled chemically by the use of sprays
or dusts. On young trees it may sometimes be feasible to jar
the trees and shake the young katydids to the ground where they
may be easily killed. The insecticide recommendations given
in the Better Fruit Program for grasshoppers also apply to
78 Florida Agricultural Experiment Stations
Fig. 75.-Broad-winged katydid eggs. Those above are almost ready
to hatch while those below have been parasitized. Note how flat the para-
sitized ones are as compared to those about to hatch.
RESTLESS BUSH CRICKET
The restless bush cricket, Hapithus agitator Uhler (Fig. 76),
has been suggested as the cause of injury occurring to Pope
Summer oranges on the east coast (12). This injury is identical
with that described as katydid injury above. Little is known con-
Insects and Mites Found on Florida Citrus 79
cerning the life cycle
of this insect. Both
nymphs and adults
have been collected on
the ground under the
tree. In the labora-
tory they readily fed
on young fruit and
produced injury iden-
tical to that found in
the field. Field injury,
severe enough to in-
volve 30 to 40 percent
of the entire crop, oc-
curs before the fruit
reaches the size of a
well as on normal
spring bloom fruit.
The use of toxa-
phene, chlordane, lin-
dane or aldrin at the
time of petal fall and
at dosages similar to
those for grasshoppers Fig. 76.-Top: The restless bush cricket.
Apparently, this insect can injure fruit se-
was found to reduce verely. Bottom: Fruit just after it was injured
the amount of injury. by the restless bush cricket or a katydid.
MOTHS AND BUTTERFLIES
Numerous species of moths and butterflies are occasionally
found on citrus trees. Some of these are sufficiently common
to be classed either as pests or as insects, arousing sufficient
questions to be worthy of mention here.
The orange-dog, Papilio cresphontes Cramer, is often a pest
of young citrus trees. As an adult, this species is a large black
and yellow butterfly. The larva grows to a length of 11/2 inches
and is an ugly brown and white individual with some yellow
markings. The coloration is such that the larva often resembles
a bird dropping on the foliage. Two black spots on the thorax
Fig. 77.-Pope summer oranges probably injured by restless bush cricket.
The fruit on the left received only one chew from the insect's mandibles.
Identical injury can be caused by katydids or grasshoppers and the citrus
root weevil may cause a similar type of damage.
Fig. 78.-Young orange dog larva and the damaged leaf (actual size).
Insects and Mites Found on Florida Citrus 81
resemble eyes and give the caterpillar a rather grotesque ap-
pearance. When disturbed, a forked reddish organ pushes out
from a fold of skin behind the head and gives off a disagreeable
odor. The chrysalis or pupa stage resembles the stub of a
During summer these caterpillars may be quite destructive
on young trees. They can be removed by hand picking in small
areas, or they may be controlled by using insecticides. A stink
bug is a predator of some importance (Fig. 79).
The orange tortrix, Argyrotaenia citrana (Fern.), is often
found on citrus in Florida.3 Although it is considered to be of
economic importance in California (4), this is apparently not
"According to G. W. Dekle of the Florida State Plant Board, there
is some question as to the proper identification of the damage caused by
the tortrix. It is possible that it is caused by Platynota stultana (Wlshm.),
the fruit scarring worm.
Fig. 79.-Right: Large orange dog larva and predacious stink bug actually
feeding on the larva (actual size). Left: Pupa of orange dog.
82 Florida Agricultural Experiment Stations
so in Florida. They feed on the young fruit which results in
scars about the stem end, rarely causing more than a very super-
ficial scarring. In the spring, a large number of the tiny dropped
fruits occasionally will be scarred (46). However, no effort
Fig. 80.-Orange-dog adult butterfly (about half size).
at control is made. By late May a high percentage of the larvae
The caterpillar is straw-colored and about 1/2 inch long when
full grown. The adult is a small brownish-colored moth.
Insects and Mites Found on Florida Citrus 83
At least two species of lepidop-
terous larvae are considered to be
scavengers, but once in a while they
actually feed on fruit. Laetilia
coccidivora Comst., was considered
to be a scavenger by Speare (41).
The pink scavenger worm, Pyro-
derces rileyi (Wlshm.), is the most
common scavenger found. It is
found among piles of purple scales
and mealybugs and is often present
where fruit or leaves touch each
other. It has been collected also
from heavy black scale infestations.
As noted above, the pink scaven-
ger worm occasionally feeds on green
as well as mature fruit, especially
following a heavy mealybug infesta-
tion. It may even eat through the
rind and leave a hole which may be
a source of secondary beetle infesta- Fig. 81.-Foliage damaged by
orange tortrix larva.
tion in the fruit.
Control of these insects has never been undertaken.
Once in a while, a mining insect burrows into young twigs
or into fruit (Fig. 83). No real economic loss results, but in-
dividual twigs are damaged and an occasional fruit is injured.
The cause apparently, is a tiny unidentified caterpillar. Grape-
fruit are more commonly affected than oranges.
The fall webworm, Hyphantria cunea (Drury), has been an
occasional pest of citrus. The larvae feed on foliage and web
up leaves and twigs (Fig. 84). Damage such as this is usually
on individual trees and is rare.
The corn earworm, Heliothis zea (Boddie), was collected
on Temple oranges at Lake Placid. The larvae had fed on foliage.
As with the webworm, damage is rarely caused by this common
84 Florida Agricultural Experiment Stations
At least three species of bagworms have been found by Muma
on citrus in Florida. The large species most commonly pictured
(Fig. 85) has been incorrectly identified in the past. It is
Oiketus abboti Grt., and it is suggested that it be called the
citrus bagworm. A smaller species (Fig. 86) is Platoeceticus
gloveri (Pack.). The common name orange basket worm is
suggested by M. H. Muma. A third species, as yet unidentified,
was noted by Muma in a grove near Tavares. The bag is shaped
like a tapered tube and measures 1/2 to 3/4 of an inch in length.
Fig. 82.-Injury of pink scavenger worm. The dark areas are where
the larva has gouged the rind of the young fruit. Adult of the pink
scavenger worm is shown in the lower right corner.
The life cycle of a bagworm is unusual. The larva lives en-
cased in a silken bag which has small sticks and bits of leaves
attached to the outside. It pupates in this bag, and in the case
of the female, the eggs are laid within this bag. The female dies
Insects and Mites Found on Florida Citrus 85
following oviposition and the eggs hatch the following spring.
The offspring from this one female will infest the adjacent
foliage and cause damage as noted in Fig. 85.
Fig. 83.-Injury to grapefruit caused by leaf miner. There is a spot
on the upper left quadrant of the fruit where early injury of orchid thrips
may be seen.
Larvae of the hag moth, Phobetron pithecium (J. E. Smith)
(Fig. 87), puss caterpillar, Megalopyge opercularis (J. E.
Smith) (Fig. 88), and saddleback caterpillar, Sibine stimulea
(Clemons) (Fig. 90), are all found occasionally on citrus. None
of these cause any economic damage. These species have poison
hairs which cause a nettle-like sting to the skin. Occasionally
they are the source of minor difficulties during picking operations.
Several species of psocids have been found on citrus. This
group has not been adequately identified and there is confusion
as to the exact names and number of species. All are lichen,
86 Florida Agricultural Experiment Stations
fungus or alga feeders, but their presence often disturbs the
Fig. 84.-Fall webworm larvae and injury on orange leaves.
One species, Psocus venosus Burm. (58), lives in colonies on
the trunk and large limbs of the tree. The entire colony runs
at one time like a flock of sheep. Although some growers have
attributed damage to this species, they are actually harmless.
The adults are much the color of the bark and are inconspicuous
except when the colony moves. This species often forms large
silken webs which may cover the trunk or large limbs (Fig. 91).
Fig. 85.-Leaf injury caused by the feeding of bagworm larvae. Larvae
covered with trash can be seen in the picture and a pupa case is also
visible on the left side. This species is Oiketus abbotii. (% actual size.)
Fig. 86.-Pupa case of orange basket worm, Platoeceticus gloveri.
Fig. 87.-Left: Larva of hag moth as it is feeding on grapefruit foliage.
Right: Adult hag moth with wings folded. The white patches, on each
side are white areas on the legs of the moth.
Fig. 88.-An unidentified army worm feeding on
orange foliage near Lake Placid.
Fig. 89.-Puss moth larva on citrus leaf.
Insects and Mites Found on Florida Citrus 89
Muma (unpublished data) has found that another unidentified
and smaller species also makes such webs.
Fig. 90.-Saddleback moth larvae on citrus leaf.
Two species with pink-colored nymphs, which live in scanty
webs on the under side of leaves, are Etopsocus californicus
(Bks.) and E. pumilis (Bks.).4 They lay groups of pearly white
eggs which are often seen on foliage when inspected with a
hand lens. These species are often associated with six-spotted
mites and purple scale infestations.
Another clear winged species, Teliapsocus conterminus
(Walsh.),4 is often found with the latter two species; more
often, it is associated with heavy scale infestations. All these
species measure more than 1/g inch in length when full grown.
The orange jassid, Oncometopia undata (Fab.), is an oblong
bluish-bronze leaf-hopper which is often seen on citrus trees.
SCollected by M. H. Muma.
90 Florida Agricultural Experiment Stations
The adult measures almost 1/ inch long. This insect is a rather
pretty one, but when approached, it quickly disappears from
view. Although Watson (58) suggested that control was some-
times necessary, the writers have never observed such to be
Fig. 91.-Tree trunk covered by psocid web. This does not harm the tree.
Insects and Mites Found on Florida Citrus 91
The authors wish to gratefully acknowledge the technical assistance on
nomenclature of George W. Dekle, Florida State Plant Board, A. N. Tissot,
Florida Agricultural Experiment Station; and Fran. E. Fisher, Florida
Citrus Experiment Station; the helpful criticism of Martin H. Muma;
and others, too numerous to mention, who permitted the use of pictures,
who read the manuscript or who offered constructive help and criticism.
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12. GRIFFTHS, J. T. Observations on peel injury to Pope summer oranges
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13. GRIFFITHS, J. T. Some biological notes on katydids in Florida citrus
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14. GRIFFITHS, J. T. Greasy spot and factors related to its intensity and
control. Cit. Ind. 36(5): 7, 10, 11. 1955.
15. GRIFFITHS, J. T., and W. L. THOMPSON. Identification of Florida red
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16. GRIFFITHS, J. T., and W. L. THOMPSON. Progress report on some of
the aspects of purple mite control in Florida. Cit. Ind. 31(11):
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18. HUBBARD, H. G. Insects affecting the orange. USDA, Government
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explosiva and Florida scaly-bark-with implications for the Florida
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23. MUMA, M. H. Annual progress report. Fla. Cit. Exp. Sta., Lake
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25. MUMA, M. H. Ladybeetle predators of citrus aphids. Cit. Mag.
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26. MUMA, M. H. Ladybeetle predators of citrus whiteflies. Cit. Mag.
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27. MUMA, M. H. Ladybeetle predators of mealybugs. Cit. Mag. 16(8):
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32. MUMA, M. H. Three thrips predatory on citrus insects and mites in
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33. MUMA, M. H. Life cycles of four species of ladybeetles. Fla. Ent.
39(3). Sept. 1956.
34. MUMA, M. H. Factors contributing to the natural control of citrus
insects and mites in Florida. Jour. Econ. Ent. 48: 432-437. 1955.
35. MUMA, M. H., H. HOLTSBERG and R. M. PRATT. Eutetranychus banksi
(McG.) recently found on citrus in Florida. Fla. Ent. 36: 141-144.
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38. OSBURN, M. R. Comparison of DDT, chlordane, and chlorinated cam-
phene for control of the little fire ant. Fla. Ent. 31: 11-15. 1948.
39. QUAYLE, H. J. Red spiders and mites of citrus trees. Calif. Agr. Exp.
Sta. Bul. 234. 1912.
Insects and Mites Found on Florida Citrus 93
40. RHOADS, A. S., and E. F. DEBUSK. Diseases of citrus in Florida. Fla.
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41. SPEARE, A. T. Natural control of the citrus mealybug in Florida.
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42. SPENCER, H., and M. R. OsBauN. Control of the citrus rust mite.
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p. 147. 1938.
47. THOMPSON, W. L. Thrips attacking citrus fruits in Florida. Proc.
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oil emulsion and parathion for the control of scale insects on citrus.
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to the timing of oil sprays on citrus. Cit. Ind. 26(5) : 5-9. 1945.
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94 Florida Agricultural Experiment Stations
Acanthocephala femorata (Fab.), 62 California red scale, 15
Aegerita Webberi Faw., 36 Camponotus abdominalis floridanus
Alcaeorrhychus grandis (Dallas), 61 (Buckley), 67
Aleurodothrips fasciapennis (Frank- Camponotus socius Roger, 67
lin), 22 Ceratitis capitata (Wied.), 54
Aleurothrixus floccosus (Mask.), Ceroplastes ceriferus (Anderson), 27
35, 36 Ceroplastes cirripediformis Comst.,
Amblyseius quadripilis (Banks), 21 26
American grasshopper, 72 Ceroplastes floridanus Comst., 25
Anaphothrips orchidii (Moulton), 64 Chaff scale, 13
Anasa scorbutica (Fab.), 61, 62 Chilocorus stigma (Say), 20, 33
Anastatus mirabilis (Wash & Chinese ladybeetle, 58
Riley), 76 Chrysomphalus aonidum (L.), 5, 8
Ants, 67 Chrysomphalus dictyospermi
Aonidiella aurantii (Mask.) 15 (Morg.), 5, 14
Aonidiella citrina (Coq.), 5, 15 Chrysopa interrupta Schneider, 49
Apateticus cynicus (Say), 63 Chrysopa lateralis Guer., 33, 49
Aphids, 55 Chrysoplatycerus splendens How., 33
Aphid lion, 49 Chytrid, 20
Aphidius testaceipes (Cress.), 58 Cinnamon fungus, 36
Aphis citricidus (Kirk.), 56, 59 Citron bug, 61
Aphis gossypii Glov., 57, 59 Citrus bagworm, 84
Aphis spiraecola Patch., 57, 59 Citrus mealybug, 30
Aphycus flavus How., 23 Citrus red mite, 43
Argentine ant, 67 Citrus root weevil, 69, 71
Argyrotaenia citrana (Fern.), 81 Citrus whitefly, 35
Armored scales, 5 Cloudy winged whitefly, 35, 36
Arphia granulata Sauss., 76 Coccophagus lycimnia (Walk.), 23
Artipus floridanus Horn, 69, 70 Coccophagus pulvinariae Dozier, 23
Aschersonia aleyrodis Webber., 36 Coccophagus scutellaris (Dalm.), 23
AQchersonia goldiana Sacc. and Coccus hesperidum L., 23
Ellis, 36 Coccus viridis (Green), 27
Aspidiotiphagus citrinus (Craw.), 22 Collared ladybeetle, 58
Aspidiotiphagus lounsburyi (B. & Colletotrickum gloeosporioides Penz.,
P.), 22 44
Australian mealybug ladybeetle, 32 Coniopteryx vicina (Hagen), 21, 43
Avocado whitefly, 35 Convergent ladybeetle, 58
Corn earworm, 83
Baccha clavata (F.), 58 Cotton stainer, 62
Baccha fasciapennis Say, 58 Cottony cushion scale, 29
Bag worms, 84 Cryptolaemus montrouzieri Muls., 32
Barnacle scale, 26, 27 Cycloneda sanguinea (L.), 58
Bay whitefly, 35
Beetles, 68 Decadiomus bahamicus (Csy.), 32, 34
Bemesia inconspicua (Quaint.), 35 Delphastus pallidus (Lee.), 36, 38
Bird grasshopper, 72 Jelphastus pusillus (Lec.), 36, 38
Bitoma carinata (Lee.), 72 Dialeurodes citri (Ashm.), 35
Black citrus aphid, 57, 59 Dialeurodes citrifolii (Morg.), 35
Black hunter thrips, 22, 43 Dictyospermum scale, 5, 14
Black scale, 24 Dormyrmex pyramicus var. flavus
Blood red ladybeetle, 58 McCook, 67
Brevipalpus australis (Tucker), 53 1
Brevipalpus phoenicis (Geijskes), 53 Dstye (H.-S.), 624
Broad mite, 52 Dysdercus suturllus, (H.-S.), 62
Broad winged katydid, 76
Brochymena florida Ruckes, 63 Eastern lubber grasshopper, 73
Bronzing, 40 Ectopsocus californicus (Bks.), 89
Brown Lacewing fly, 33 Ectopsocus pumilis (Bks.), 89
Brown whitefly fungus, 36 Entomogenous fungi, 20, 32, 36, 58
Bull ant, 68, Entomophthora frensenii Now., 68
Butterflies, 79 Entomophthora fumosa Speare, 32
Insects and Mites Found on Florida Citrus 95
Eotetranychus aexmaculatus Riley, Little scale eating, 21
49 Little steel blue, 38
Euchistus obscurus (P deB), 63 Little red, 21
Euchistus servus (Say), 63 Little tan, 38
Eutetranychus banks (McG.), 51 Pictured, 32
Euthochtha galeator (Fab.), 61 Southern two-spotted, 49
Ezochomus marginipennis children Stethorus, 49
Muls., 21 Twice stabbed, 20
White tailed, 58
Fall webworm, 83 Laetilia coccidivora Comst., 83
False spider mites, 53 Leaf cutting ant, 67
Fern scale, 16 Leaf footed plant bug; 61
Fire ant, 68 Leaf miner, 83
Florida flower thrips, 63 Leaf notcher, 69
Florida red scale, 58 Lecaniobius cockerellii Ashm., 23
Florida wax scale, 25 Lepidosaphes beckii (Newm.), 5, 6-8
Frankliniella cephalica bispinosa Lepidosaphes gloverii (Pack.), 5, 16
(Morgan), 63 Lepra explosive, 53
Fuller's rose weevil, 69, 70 Leprosis, 53
Fusarium aleyrodis Petch, 36 Leptoglossus gonagra (Fab.), 60, 61
Leptoglossus phyllopus (L.), 61
Glover's scale, 5, 16 Leptothrips mali (Fitch), 22, 43
Grasshoppers, 72 Leptothrips sp., 64
Greasy melanose, 41 Leptomastidea abnormis (Grit), 33
Greasy spot, 41 Leptomastix dactylopii How., 33
Green citrus aphid, 57, 59 Little fire ant, 68
Green lacewing fly, 33 Long scale, 5, 16
Green peach aphid, 57 Lubber grasshopper, 73
Green scale, 27
Green shield scale, 28 Mealybugs, 30
Mealy wing, 21, 43
Hag moth, 85, 87 Mediterranean fruit fly, 54
Hapithus agitator Uhler, 78 Megalopyge opercularis (A. & S.),
Harmonia dimitata 15-spilota Hope, 85, 88
58 Melanoplus femur-rubrum propin-
Heliothrips haemorrhoidalis quus Scudder, 75
(Bouche), 65 Meliola camelliae (Catt.) Sacc., 23
Heliothus armigera (Hbn.), 83 Melon aphid, 57, 59
Hemispherical scale, 25 Mesophyll collapse, 48
Hemitarsonemus latus (Bks.), 52 Metatetranychus citri (McG.), 43
Hippodamia convergens Guer., 58 Microcentrum rhombifolium
Hirsutella Besseyi Fisher, 20 (Sauss.), 76
Hirsutella Thompsonii Fisher, 42 Microterys flavus (How.), 23
Hyphantria cunea (Drury), 83 Microweisea coccidivora Ashm., 21
Icerya purchase Mask., 29 Mulberry whitefly, 35
Iridomyrmex humilis Mayr, 67 Myiophagus sp. Thaxter, 20
Japanese wax scale, 27 Nectria diploa B. & C., 20
June beetle, 72 Neoconocephalus trips (L.), 77
Katydid, 76 Neotermes castaneus (Burm.), 67
Katydid injury, 76, 78 Nephaspis gorhami Csy., 36
Katydid injury, 76, 78 Nezara viridula (L.), 62
Lacewing fly, 33, 49
Ladybeetles, Oiketicus abbotii Grt., 84
Australian, 32, 34 Olla abdominalis var. plagiata Csy.,
Blood red, 58 33, 49
Chinese, 58 Oncometopia undata (Fab.), 89
Collared, 58 Orange basket worm, 84
Convergent, 58 Orange dog, 79
Little black, 38 Orange jassid, 89
Little black and white, 38 Orange tortrix, 81
Little mealybug eating, 32 Orchid thrips, 64
96 Florida Agricultural Experiment Stations
Pachneus litus (Germar), 69, 71 Scolothrips sezmaculatus (Perg.),51
Pachneus opalus (Oliv.), 72 Scolytidae, 72
Pantomorus godmani (Crotch.), 69 Scudderia sp., 77
Papilio cresphontes Cramer, 79 Scutellista cyanea Mots., 25
Paraleyrodes perseae (Quaint.), 35 Scymnillodes subtropicus (Csy.), 36
Parlatoria pergandii Comst., 5, 13 Scymnus collaris Melsh., 58
Paroxya atlantica Scudder, 75 Scymnus flavifrons Melsh., 32
Paroxya clavuliger (Serville), 75 Scymnus partitus Csy., 58
Pentatomidae, 62 Shot hole borer, 72
Phobetron pithecium (A. &. S.), 85 Sibine stimulea (Clemons), 85
Pictured ladybeetle, 32 Six spotted mite, 49
Phyllocoptrutd oleivora (Ashm.), 39 Snow scale, 5, 15
Pineapple mealybug, 31 Soft brown scale, 23
Pink-headed fungus, 20 Solenopsis geminata (Fab.), 67
Pink scavenger worm, 83 Solubrea pugnax (Fab.), 63
Pinnaspis aspidistrae (Sign.), 5, 16 Sooty mold, 23, 24, 32, 35
Plant bugs, 60 Southern green stinkbug, 62
Platoeceticus gloveri (Pack.), 84 Sphaerostilbe auranticola (Berk. &
Platynota stultana (Wlsm.), 81 Br.) Petch, 20
Platypus compositus Say, 72 Spider mites, 43
Podisus maculiventris (Say), 63 Spirea aphid, 57, 59
Podisus sagitta (Fab.), 63 Stethorus utilis (Horn), 49, 51
Pogonomyrmex badius (Latr.), 67 Stink bugs, 62
Prospaltella aurantii (How.), 22 Sweet potato whitefly, 35
Proxys punctulatus (P deB), 63 Sympherobius barber (Bks.), 33
Pseudococcus brevipes (Ckll.), 31 Syrphid fly, 58
Pseudoococcus citri (Risso), 31
Pseudhomalapoda prima (Gir.), 22 Teliapsocus conterminus (Walsh.),
Psocids, 85 49
Psocus venosus Burm., 86 Tenebrionidae, 72
Pulvinaria psidii Mask., 28 Termites, 65
Protopulvinaria pyriformis (Ckll.), Tetraleurodes mori (Quaint.), 35
28 Texas citrus mite, 43, 51
Pumpkin bugs, 60 Thrips, 63
Purple mite, 43 Toxoptera aurantii (Fonsc.), 57, 59
Purple scale, 5, 6 Trashbugs, 33, 48
Puss moth, 85, 88 Trialeurodes floridensis (Quaint.), 35
Pyriform scale, 28 Tristeza, 56
Pyroderces rileyi (Wlshm.), 83 Turtle back scale, 23
Typhlodromus conspicuous Garman,51
Quick decline, 56 Typhlodromus floridanus Muma, 51
Typhlodromus peregrinus Muma, 21
Red aschersonia, 36
Red headed fungus, 20 Unarmored scales, 22
Red scale, 5, 8-13 Unaspis citri (Comst.), 5, 15
Red spider, 43
Restless bush cricket, 78 Vedalia beetle, 29
Reticulitermes flavipes (Kollar), 65 Verticillium cinnamoneum Petch, 36
Rodolia cardinalis (Muls.), 29
Romalea microptera (Beauv.), 73 Wasmannia auropunctata (Roger),
Russetting, 40 68
Rust mite, 39 Wax scale, 25
Saddleback moth, 85, 89 White fringe fungus, 36
Saissetia hemisphaerica (Targ.), 25 Whiteflies, 33
Saissetia oleae (Bern.), 24 Withertip fungus, 44
Scaley bark, 53 Woolly whitefly, 36
Schistocerca americana americana
(Drury), 72 Yellow aschersonia, 36
Schistocerca obscure (Fab.), 75 Yellow scale, 5, 15
take a i.
Late rust mite injury on oranges. This injury will take a high polish and
the fruit may be shipped as bronzed fruit to the fresh fruit market.
Adult Meditetrra ean fruit flies on a fruit. These flies are a little smaller
than a housefly. (Courtesy USDA.)