Official Organ of the Florida Entomological Society
Vol. IX SPRING NUMBER No. 1
A NEW GENUS, A NEW SUBGENUS AND SEVEN
OF THYSANOPTERA FROM PORTO RICO
A. C. MORGAN,
Associate Entomologist, U. S. Department of Agriculture
Cercyothrips. New Genus. Family Thripidae.
Antennae 8-segmented, maxillary palpi apparently only 2-segmented,
sense cones on segments 3 and 4 forked, mouth cone broad and heavy reach-
ing nearly across prosternum. Head produced between antennae which
are inserted far apart close to the eyes, and are directed somewhat laterally.
Cheeks strongly converging posteriorly. Prothorax shorter than the 'head
and without the usual spines at the angles. Anterior and intermediate
tibiae unarmed; legs stout. Wings well-developed, with two veins sparsely
set with spines. 9th segment of abdomen the longest. Spine on abdominal
segments 9 and 10 stout.
This genus suggests Limothrips somewhat in the projection of the
head between the eyes. The antennae are very similar to those of some
species of Sericothrips, notably variabilis.
Cercyothrips striatus. New Species.
Female:-Measurements of Holotype: Length 0.95 mm.; head, length
0.112 mm., width through eyes 0.163 mm.; prothorax, length 0.103 mm.,
width 0.155 mm.; mesothorax, width 0.20 mm.; abdomen, greatest width
Dimensions of antennal segments in microns:
1 2 3 4 5 6 7 8
Length ...................|- 22 36 60 61 49 53 12 I 18
W idth .....................I 28 28 20 18 16 15 7 6
General color by reflected light: eyes deep orange, whole body,
especially prothorax, heavily tinged with orange, also all femora and tibiae
and two basal segments of antennae and segment 6, basal half of segments
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3-5, segments 7-8 and tarsi lemon yellow. Color by transmitted light; head,
thorax, abdomen, femora,,tibiae, and segment 2 of antennae deep brown;
tarsi, distal half of segments 3, 4, 5 and segments 6-8 light brown, 7 and 8
lighter than 6, proximal half of segments 3 to 5 gray brown. Wings clear
in basal 2/5 and distal 1/5 except over veins, remainder brown, forming a
broad band. Posterior wings clear except for dark brown median vein.
Head nearly straight across front to middle of insertion of antennae,
thence curving forward very nearly to base of second antennal segment
forming a projection between the antennae as broad as basal segment.
Eyes not protruding, rather coarsely facetted, minutely pilose, occupying
slightly more, than half the width of the head and 2/3 its length; with
orange pigmentation. Ocelli large, approximate, the posterior pair opposite
center of eyes, slightly fore-shortened due to their position on sides of
hump, anterior ocellus on front margin of hump and strongly directed
forward. Cheeks slightly roughened and converging evenly and strongly
to prothorax. Dorsal surface behind ocelli very distinctly though finely
transversely striate, and very slightly so in front of anterior ocellus. Spines
upon head sparse and minute. Antennae situated rather low on front
bearing few spines and those small. Branched sense cones placed as in
Frankliniella, but in this specimen they are much enlarged and long. A
long transparent sensory hair located on inner margin of six. near the
Prothorax very distinctly though finely transversely striate, anterior
angles broadly rounding to the middle of the segment, posterior angles
slightly rounding, without long spines, although rather low down on each
anterior angle, and on posterior angles a single very short spine is visible,
remnants of the row on the posterior margin are found in a pair of very
short, rather stout spines on each side of meson. Mesonotum and metano-
tum distinctly and finely striate. Legs short and the fore pair, particu-
larly, quite stout. Femora and tarsi sparsely pubescent. Wings narrow,
ring vein heavy, at middle about 1/15 as broad as long, spines on costa
and veins small, costa bears 23, fore vein bears 9 spines situated as fol-
lows, 3 near base, 4 near middle, 1 at fourth fifth and one near tip;
posterior vein bears 3 spines all beyond middle of vein, two being near the
middle and the third just within brown area near fourth fifth. Anterior
vein runs all the way very near costa. Fringe on costa long, slender and
sparse, fringe on posterior margin long, slender and straight.
Abdomen striate on sides of first to 7th segments, constricted at
segments, broadest at about 5th segment, converging evenly from 6th
segment to the stout cone-shaped 10th segment. Conspicuous spines only
on last three segments, two lateral pair on nine and much shorter median
pair on 10 quite prominent and dark brown. The median pair on 9 consid-
erably smaller than those on 10. 8th segment bears a fine comb-like
fringe of minute spines on posterior dorsal margin. A dark chitinous
thickening extends across dorsum of segments 2 to 8 near anterior margin.
10th segment is entire above.
I' SPRING NUMBER '
Described from one female. No food plant given. Collected by Mr.
E. G. Smythe, Rio Piedros, Porto Rico, Oct. 7, 1919.
Sericothrips portoricensis, sp. nov.
Female:-Color: Head and prothorax deep brown, pterothorax and
1st abdominal segment orange brown; abdominal segments 2-5 with a
longitudinally median tan colored stripe occupying about 1/4 the width
of the segments, remainder of segments brown, segment six tan, segments
7-10 dark brown; fore and middle femora tan, hind femora nearly as dark
brown as abdominal segments 7-10, tibiae light tan, tarsi lemon yellow;
antennal segments 1 and 2 straminious, base of 3 gray, remainder of an-
tennae brown, shading from light lemon on 3rd segment to dark brown on
segments 6-8 with bases of 4 and 5 gray brown. Wings deep brown, basal
fourth (except scale which is brown) 'gray, a gray cross band in the fourth
fifth; hind wings gray except for dark brown median vein.
Head very short, scarcely 1/4 as long as broad, surface very finely
striate; eyes dark blackish brown, occupying slightly more than half the
width of head and nearly its entire length, pilose with a few conspicuous
hairs, facets large; ocelli equidistant, large, margined inwardly, with very
dark orange crescents; post-ocellar spines large and prominent, a few
small spines on cheeks, four spines across front below anterior ocellus a
little larger than setae between facets of compound eyes; mouth cone long,
reaching across prosternum, stout, cone-shaped with sides slightly convex;
antennae normal except for the branched sense cones which are especially
large and thick.
Prothorax only about half as long as wide, quite thickly covered with
fine transversely anastomosing lines, sides convex; each posterior margin
bears a very stout long spine a short distance from lateral margin, between
these two spines there is a chitinous thickening very close to posterior
margin; this chitinous thickening extends cephalad from each suine in an
arcuate line about 2/3 across the pronotum, each side line boing
joined across the front by a concave thickening; the enclosed pronotal area
is somewhat. darker than the remainder of the segment and bears two
small spines on each side, one at the anterior angle and the other midway
the lateral margin; the prothorax bears two pairs of small spines on its
anterior margin, the first spine of each pair being about 1/8 the width
of the anterior margin from the anterior angle and the second spine about
1/8 this width distant from the first. The mesoscutum is very thickly
covered with finely anastomosing lines and bears six small but distant
spines, one near each lateral angle, one each side the meson about midway
between poterior and anterior margins, the other two spines stand, one
on each side about half-way between lateral line through preceding two
spines and posterior margin but about twice as far from meson as the
preceding; the metascutum is longitudinally striate and bears four spines
in its anterior margin somewhat smaller than those on pronotum, metas-
cutetlum smooth. Legs not especially long; wings normal to the genus, at
the base about 1/9 as broad as long, at the middle about 1/18 as broad
as long. Costa bears about 24 spines, fore vein about 20, and sometimes 2
on hind vein near tip.
THE FLORIDA ENTOMOLOGIST
Abdomen normal to the genus in shape. The lighter color of 6th
segment and the light stripe along meson due partly to the absence of the
very fine posteriorly directed dark spines found on segments 7-10 and
on darkened posteriors of other segments. Segments 2 to 7 each with a
dark chitinous thickening near anterior margin. Spines on last two seg-
ments rather short. Tenth segment entire above.
Measurements; length 1.10 mm.; head, length0.04 mm., width 0.16 mm.;
prothorax, length 0.114 mm., width 0.204 mm.; mesothorax, width 0.26 mm.;
metathorax, width 0.24 mm.; abdomen, width at 4th segment 0.28 mm.
Dimensions of antennal segments in microns:
S11 2 1 3 41 5 61 7 8
Length ............... 26 36 57. 57 1 44.9] 53 l1 11 I1 16
Described from 2 females collected at Rio Pedrts, Porto Rico, March
25, 1920, by E. G. Smythe.
The chitinous thickening on the pronotum and the color will differ-
entiate this species from other species of the genus.
Anaphothrips bicolor, sp. nov.
Female:--Holotype--Coloration: brown and yellow; head, mesothorax,
metathorax, first two and last four abdominal segments, first two and
last four antennal segments and second quarter of fore wing brown-the
head and last three abdominal segments somewhat darker than thorax, the
first antennal segment and second quarter of wing somewhat lighter than
thorax. Middle and hind coxae light brown. Remainder of insect grayish
yellow except basal fourth of fore wing which is colorless, the apical half
which is light gray and the 3rd and 4th antennal segments which are very
light yellowish. The eyes tinged with orange pigment, the ocelli are light
yellow margined inwardly with very dark orange crescents.
Head a little less than 1/5 broader than long, obtusely angular in
front of eyes, cheek very slightly convex, eyes slightly protruding, occupy-
ing nearly 2/3 the width of head and fully 1/2 its length; ocelli small,
approximate, the posterior pair on line with posterior third of compound
eyes. Surface faintly and sparcely transversely striate. Four tiny spines
stand in a row across front half-way between anterior ocellus and frontal
angle, a row of six similar spines cross the head just behind eyes, and a
spine of similar size stands just in front of each post-rior Iell1us. Mouth
cone heavy and blunt, reaching 3/4 across prosternum. Antennal joints
rather short, sense cones small.
Prothorax somewhat longer than head, about 2/3 as long as broad,
broadest across posterior margin, surface smooth and angles without
spines. Mesothorax 1/4 broader than prothorax and without visible spines;
metathorax about 1/9 narrower than mesothorax. Legs short and thick,
unarmed. Wings broad at base, attaining 8th abdominal segment. First
third of costal margin bare, at the middle 1/12 as broad as long. The two
longitudinal veins indistinct. Spines on wing tiny and transparent. Costa
bears about 20, fore vein with a basal group of 3 spines, 3 spines in the
brown wing band and 3 widely separated spines beyond, the last one near
tip; hind vein bears 7 spines which are more widely separated toward tip
than toward base of wing.
Abdomen stout. Eighth segment with a comb of spiniferous tubercles
on dorsal posterior margin. Last three segments sharply conical. A small
spine at posterior angle of 7th segment, a larger one on posterior angle
of 8th segment; the 9th bears six long, light brown spines across its pos-
terior margin. The spines on 10th segment nearly as long as those on
9th. 10th segment split open above.
Measurements-holotype:--Length 0.965 mm.; head, length 0.112 mm.,
width through eyes 0.13 mm.; prothorax, length 0.122 mm., width 0.14 mm.;
mesothorax, width 0.20 mm.; metathorax, width 0.179 mm.; abdomen, width
at middle 0.236 mm.; length of antennal segments in microns:
_2 11 1 31 41 5 6| 7 8
I 16.3 30 I 32 1 34 j 34 f 44.9 f 8 13
Described from 4 females collected on cane, Bayamon, Porto Rico,
May 5, 1920, by G. N. Wolcott.
PROLISSOTHRIPS NEW SUBGENUS
Head slightly wider than long, quadrate, very slightly narrowed pos-
teriorly; eyes larger than in Lissothrips and directed more laterad; anten-
nae as in Lissothrips, except that sixth segment is slightly longer than
seventh. Mouth cone broad and sharp-pointed at tip, extending only 3/4
across prosternum. Labium broad and broadly rounded. Prothorax very
slightly shorter than head, the five pairs of bristles very noticeably
expanded at tips and much shorter than in Lissothrips. Fore tarsi
unarmed. Most of the abdominal spines expanded at tips.
The shorter mouth cone, the shorter and more expanded spines and
the quadrate head suggests a genus distinct from Lissothrips, but since the
only specimen known is a male, I hesitate to give it generic rank, preferring
to place it in a subgenus under Lissothrips, to which it is so very closely
Lissothrips (Prolissothrips) stratulus sp. nov.
Male:-General color uniform dark brown, with scarcely any shading,
except for second antennal segment, which is slightly lighter and the 3rd
antennal segment, Which is gray.
Head, quadrate, about 1/4 wider than long, cheeks slightly roughened
and slightly convex. Eyes directed somewhat laterad, occupying about
half the width of the head and 1/3 its length. Ocelli wanting. Post ocular
bristles of medium length and markedly expanded at tips. Mouth cone
pointed at tip and reaching 3/4 across prosternum, labium broad and
broadly rounded, over-reaching the mouth cone.
Prothorax a little shorter than head, measured through coxae 2 1/2
times as broad as long and 1 2/3 times as broad as at anterior margin;
bearing five pairs of well-developed spines-not nearly as long as those
of Lissothrips muscorum-which are markedly expanded at tips. Meso
and metathorax about 4/5 as wide as prothorax through coxae. Mesonotum
THE FLORIDA ENTOMOLOGIST
with a pair of spines with expanded tips at its lateral posterior angles.
Anterior margin of mesothorax shouldered at the angles. Legs sh6rt and
stout. Tarsi unarmed. Wings wanting.
Abdomen scarcely broader than prothorax through coxae. .Posterior
margin of abdominal segments 2-9 each, with two pairs of bristles of
medium length, all expanded at tip, except the ones at lateral angles of
7th and 9th segments, respectively, which are sharp pointed. Tube stout,
spines at its tip sharp pointed and scarcely more than half the length of
Measurements: Length, 0.948 mm.-abdomen somewhat' extended;
head length, 0.089 mm.; width 0.106 mm.; prothorax, length 0.857 mm.;
width on anterior margin 0.122 mm., through coxae 0.204 mm.;'mesothorax,
width 0.17 mm.; metathorax, width 0.155 mm.; abdomen, width at 3rd seg-
ment 0.204 mm. Tube, length about 0.073 man.; width at base, 0.053 mnm.;
at tip, 0.024 mm. Length of antennal segments in microns:
1 2 j3 4 5 6 ..7 .8
18 32 4 27 28 32 28 28
Described from one male taken byF Sein, from stomach of a lizard,
Anolis stratulus Cope collected at Santa Catalina, Porto Rico, May 9, 1924.
Elevation 1,500 feet.
Gastrothrips fuscicauda, sp. nov.
Female:-Holotype, color: Head, thorax and abdomen very dark
brown; all femora, middle and hind tibiae dark brown; fore tibiae brown,
fuscus on outer margin; fore tarsi yellowish brown, middle and hirid tarsi
light brown; first antenna segment brown, the' seboid a little lighter, the
third yellowish brown, the fourth colored like the second, fifth 'to eighth
dark brown; tube black.
Head longer than wide, obtusely angular in front, narrowing from
middle to base, where it is about 5/6 as wide as at middle; postocular spines
alone prominent, light brown and sharp pointed. Mouth reaching,.about
3/4 across prosternum, constricted near tip, rounded. Labium broad and
broadly rounded. Eyes occupy nearly 2/3 width of head through them and
not quite 1/3 its length, facets smaller than ocelli. Ocelli rather large,
posterior pair situated in front of middle of eyes and contiguous thereto.
Anterior ocellus on extremity of head and pointing forward. Antennae
normal, 5th to 7th segments stalked, 3rd segment narrow at base-inverted
Prothorax only half as long as head and only about 1/3 as long as the
width through coxae; all spines present, reduced in size, those on anterior
margin tiny, those on posterior angles alone prominent, mesothorax about
1/9 broader, and metathorax very little broader than prothorax. Legs
rather short and slender, except the fore pair. Fore femora enlarged,
about 2/3 as broad as head, fore tarsus armed with a stout tooth about as
long as diameter of tarsus. Wings present, but not spread, and the details
cannot be seen.
Abdomen stout. Spines prominent alone on last four segments, those
on 9th segment being nearly s' long as the tubed,th6se'at tip of tube about
5/6 as long as tube...
Measurements: Length 2.03 mrm.; head, length 0.24 mm.; width at middle
0.224 mm.; prothorax, length 0.129' mm., width through coxae 0.38 mm.;
mesothorax, width 0.422 mm.; metathorax, width 0.396 mm.; abdomen, width
at 5th segment 0.47 nrm. Tube, length 0.19 mm.; width at base'0.129 mm.,
at tip 0.06 mm.; very slightly constricted at tip. Dimensions of antennal
segments in microns:
1 2 3 5 4 ,5 1,. 6 7 .8
Length .................. 51 60 1 86 1 77.61 60 1 45 1 ? ?
Width .- ....-:.-. 40 35 1 :34. 1 -,34 34 *].29. (., 25 17
Described from 1 female collected in Porto 'Rico frbm 'the stomach of a
lizard, by Mr. G. N. Wolcott. This species may be easily distinguished
from its nearest Congener G. texannus Hood by its greater size.
Gastrothrips anolis, sp. nov. .
Female:-Color, head light brown; thorax and all but 10th abbnominal
segment dark blackish brown; tube dark orange; forp femora yellowish
brown, .fuscus on outer side, middle and hind femora slightly lighter brown
than head, with decided fuscus tinge toward bases; fore tibiae lighter
brown than head, middle and hind tibiae darker 'brown than head, but not
so dark as abdomen; fore tarsi pale yellow,, middle and nd.tarsi pale
brown; 1st antennal segment deep yellow, 2nd, yellowish brown, 3rd light
brown with fuscus tinge at base and:onsides, 4th dark brown, 5th to 8th
dark blackish brown.
Head as wide as long, widest just behind eyes, at the base only 4/5
as broad as just behind eyes; eyes medium, occupying only slightly more
than half the width of the head and not quite 1/3 its,length, cheeks set
with a few small spines; postocular- bristles, well developed, yellow; ocelli
small, the posterior pair opposite the middle of eyes. and. contiguous
thereto, anterior ocellus on line with front of eyes; mouth cone reaching
3/4 across prosternum, constricted near the tip and pointed, labium broad
and broadly rounded; antennae normal, 1st joint cylindrical, 4th-7,th
Prothorax about 4/5 as long as head and twice as broad' (through
coxae) as long; all the usual spines present, sharp pointed, although the
anterior marginals are small. Mesothorax only slightly broader than pro-
thorax, sides nearly parallel, metathorax nearly as broad as mesothorax;
legs of medium size, fore femora slightly thickened, fore tarsi unarmed;
legs sparsely clothed with long setae.
Abdomen stout, broadest at about 6th segment. Spines well-developed
only on last four segments; those on 9th segment being nearly as long as
the tube. Tube stout, rugulose, constricted near, but not darkened at tip.
Terminal hairs scarcely as long as basal width of tube.
Measurements:-Holotype. Length 1.6 mm.; head, length 0.215 mm.,
width 0.215 mm.; prothorax, length 0.172 mm.; width through coxae 0.344 mm.,
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mesothorax, width 0.379 mm.; metathorax, width 0.361 mm.; abdomen, width
at 6th segment 0.49 mm.; tube, length 0.18 mm., width at base, 0.094 mm.,
width at tip 0.051mm. Dimensions of antennal segments in microns:
I 1 2 1 3~~ 4 1 5 1 6 7 8
Length ................. 50 61 81.61 69 67 61 44.9 44.9
Width ................... 44.9 36.7 1' 32.6 35 35 30 23 13
Described from 1 female collected from the stomach of a lizard, Anolis
pulchellus D. & B. Porto Rico. G. N. Wolcott, collector.
This species may be distinguished from its nearest congener, G rufi-
cauda Hood, by the yellow color of the 1st antennal segment and by the
light brown head.
Diceratothrips wolcotti, sp. nov.
Female:-General color dark blackish brown; fore femora yellowish
brown at tip inside and bases of all femora yellow brown; hind and inter-
mediate tarsi brown, fore tarsi bright yellow brown; antennal segments
1 and 2 and all but tip of 3 yellow brown, remainder of antennae dark
brown. Fore wings brown in basal half, fading to gray brown in apical half;
hind wing shaded like front wing, but lighter; both wings with two dark
brown longitudinal stripes running from near base to abdut middle of
wing; one stripe near anterior margin of wing, the other through the center.
Head 1/4 longer than wide-cheeks slightly convex-narrowed some-
what behind and constricted just before a collar-like thickening very
near posterior margin; surface roughened, cheeks set with a few short,
stout spines; eyes moderate in size, finely facetted, not pilose; ocelli large,
well separated, posterior pair very near inner margins of eyes and stand-
ing almost entirely back of middle of compound eye; anterior ocellus in a
depression in front and strongly inclined forward. Post ocular bristles
long and sharp; the pair of bristles on front laterad of anterior ocellus
large and blunt, reaching to middle of 2nd antennal segment, just mesad
of each of these bristles may be seen a small bristle about 1/5 as long as its
companion. Antennae normal to the .genus, twice as long as head. Mouth
cone broad and broadly rounded at tip; reaching 3/4 across prosternum.
Prothorax large and heavy, nearly twice as broad through coxae as
on anterior margin, anterior margin strongly concave. All the usual
bristles present, only those on posterior angles prominent, anterior mar-
ginals minute. Meso and metathorax broad and heavy; mesothorax but
little wider than prothorax through coxae. Wings broad but short, barely
attaining posterior margin of 5th abdominal segment; enlarged toward
tip, posterior margin with about 37 accessory hairs near tip. Legs of
medium length; middle and hind femora strong, fore femora incrassate
with about 3 short spines near the middle within, surface sparsely clothed
with smaller spines; middle and hind femora similarly clothed; middle and
hind tibiae each with two long setae without, set at end of second fifth and
near tip, respectively; fore tarsus with a much shorter seta without just
before middle. Fore tarsi with a blunt tooth.
Abdomen well developed, rather long, with long spines at lateral pos-
terior angles of 5 to 9-a single spine on 5 and 6 and a pair on 7 and 8;
9, with the usual circlet, which is nearly as long as tube; spines on tip of
tube only about 1/3 as long as tube.
Iolotype:-Measurements, length 4.40 mm.; head, length 0.43 mm.,
width 0.344 mm.; prothorax, median dorsal length 0.224 mnm., width through
coxae 0.594 nim.; mesothorax, width 0.62 mm.; metathorax, width 0.603 mm.;
abdomen, width at 5th segment 0.594 mm.; tube, length 0.49 mm.-about 3
times as long as 9th segment-width at base 0.146 mm., at tip 0.06 mmn.;
fore femur, width 0.21 mm. Dimensions of antennal segments in microns:
1 21 31 4| 5 6\ 7 8
Length ................ 51 94.8 224 172 137 103 901 43
Described from two females. Holotype from Cayey, Porto Rico, on
leaves of Ingavera, 1923. Paratype from Port Cangrejos, Porto Rico, on
cotton boll. G. N. Wolcott collector of both specimens.
Named in honor of Mr. G. N. Wolcott, in recognition of his interest in
collecting this order.
This species may be readily separated from its congeners by the col-
oration of the first two antenna segments and by the long setae on the
front lateral of the anterior ocellus.
ANOTHER YEAR OF THE CITRUS APHIS
J. R. WATSON
(Contribution from the Entomology Laboratory, Fla. Ag. Exp. Sta.)
Between April 18 and 20 two days of hot, humid weather
caused such a severe epidemic of Empusa among the green
aphids of citrus (Aphis spiraecola, probably identical with
Aphis pomi), as to bring them under practical control. Altho
the aphids are at this date (May 11) again increasing and may
injure the "June growth," the season is getting so far advanced
that it is not probable that much more damage will be done this
year. For several weeks their numbers had been sharply
10' THE FLORIDA. ENTOMOLOGIST
decreasing, due to the maturing of the first flush of growth, but
after the epidemic of Emusa it required considerable search to
find enough live aphids to keep our life history work going. It
was estimated that 99.9% of the aphids perished in the epidemic.
Last year the destruction was even more complete, but did not
occur until the middle of June, nearly two months later than
The damage done has been great, in the aggregate much
greater than last year. In the territory where the aphis
appeared early in the spring of 1924 (in Pinellas, Hillsborough
western Polk and southward to Lee County) the general opinion
of the growers is that this year's infestation was somewhat less
severe than last year's. But the territory severely infested this
year has been so much more extensive that the sum total of
damage done has been much greater. Undoubtedly the crop of
fruit has been much reduced, altho the short crop in prospect
for .next winter's harvest cannot be entirely laid at the door of
the aphids. Certainly the, aphids are. not responsible for the
short grapefruit crop. But the damage does not stop. at this
year's crop. The destruction of the young growth by the aphids
this spring has undoubtedly shortened next year's crop, i. e., the
crop to be harvested during the season of 1926-27. This is indi-
cated by the observation that the trees severely injured early in
the spring of 1924 put out very little bloom this year and are
carrying very little young fruit.
In addition to the loss of fruit and of growth on the young
trees, the growers have been put to a heavy expense for insecti-
cides and labor expended in the application of the same. Nat-
uurally, largely due to the inexperience of the growers with this
new pest, much of this has been largely wasted., Insecticides
have been applied at the wrong time or with insufficient thoro-
ness, and, unfortunately, insecticides of poor quality have been
As a result of this year's experience a number of outstanding
facts are apparent.
(1) The aphids do most damage in the earliest stages of the
flush of growth of the citrus, and, consequently, control meas-
ures will be most effective at that time. Half grown foliage,
blossoms and young fruit will stand a rather surprisingly heavy
infestation of aphids. An experiment carried out at Lake Alfred
illustrates this. A number of heavily infested branches bearing
very young fruit, blossoms and buds were selected. Half of these
were dipped in a soap and nicotine solution or in a "Derris oil"
solution,and all aphids killed, and the other half left for a check.
These twigs. were carefully selected in pairs of practically the
same degree of infestation, of similar size and vigor, and carry-
ing about the same number of blossoms and buds. One member
of each pair was dipped and.the other not dipped. On the dipped
twigs an average of 74% of the. blossoms set fruit, and on the
undipped 62. This difference, considering the small number of
twigs, was almost within the limits of probable error. After
the petals drop. most of the aphids attack'the calyx rather than
the young orange, altho in this case enough attacked the young
fruit to severely roughen it. Experience of last year indicates
that as these oranges mature they. will largely outgrow the
The aphids do the most damage when they attack the very
young sprouting buds,' the "buttons" or "points," as they burst
thru 'the bark. One or two aphids can completely stop the
growth of a' "button" an eight or a sixteenth of an inch long.
These embryonic twigs are often covered with aphids.' For this
reason .control measures should be- instituted upon. the first
appearance of these minute "points" of growth in considerable
numbers. Spraying, moreover, is much more effective at this
stage of growth than it is later on when there are curled leaves
in which the aphids can find protection.. Furthermore, in the
early stages of the "flush" of growth when the amount of suit-
able food is on the increase, comparatively few of the aphids
develop wings. .Hence, if one cleans up his trees at this time
they will not be as quickly reinfested. In many cases it has been
ten days or two weeks before the infestation again became heavy
enough to cause much damage. It is the maturing of the foliage
that acts as a stimulus for the development of winged aphids.
Moreover, this maturing of growth causes the wingless adults
and young to become restless and move about. The dipping
experiments on the blossoms mentioned above brought this for-
cibly to our attention. The aphids on the twigs were counted
and a recount a day or two later showed that sometimes as high
as 50% of the aphids had disappeared, while many well grown
individuals were found on the twigs which had been dipped but
a day or two before.
(2) Whatever measures are taken against the aphids should
be thoro. Under favorable weather conditions an aphidwill:bring
forth six young a day. This means that if the grower kills five-
THE FLORIDA ENTOMOLOGIST
sixths of the aphids on a tree the one-sixth left will have repro-
duced the original number in twenty-four hours, leaving out of
consideration the number eaten by predators meanwhile. Of
course, he has given the aphids more than a twenty-four-hour
setback because several days must elapse before the young
aphids can start breeding. But if he can kill 95% of the aphids
the predators can be depended on to make some impression on
The two methods of control which have been most uniformly
successful under most weather conditions are dipping and dust-
ing under tents or fumigation.
Dipping is applicable only to young trees, up to two or three
years, and then only when the new growth is mostly out on the
ends of the branches where it can easily be bent over into a
bucket. Effective and perfectly safe dips are a solution of
"derris oil," a tablespoonful to a gallon of water, or the same
amount of nicotine sulphate plus an ounce or less of soap. If too
much soap is used burning may result.
Dusting under tents has been very effective and practical, and
an average kill of 99.7% has been obtained. A crew of three
men with a battery of from six to ten tents can fumigate an acre
an hour if the trees are not over 9 or 10 feet high. Using 3 per-
cent nicotine sulphate lime dust, trees averaging 7 feet in height,
cost 8 mills per tree for dust, less than a cent. The saving of
dust on young trees, as compared with dusting in the open,
almost compensates for the increase in labor cost, and the per-
centage of kill is much higher. Different types of tents have
been designed to accommodate different sized trees. For trees
less than a year old, sheeting stretched over a framework made
of telephone wire has been satisfactory. A vegetable hamper
covered with sheeting would answer. For trees up to a height
of five feet, 6-foot "rabbit" wire fencing rolled into a cone makes
a satisfactory framework. These tents are set over a tree, which
is then dusted throu a hole in the tent. For larger trees, up to
9 feet, a tent made in the form of half a cone, with a framework
of 5/8-inch gas pipe, has been found most satisfactory. It does
not have to be lifted over a tree, only set up against it. A sheet
of cloth with one side only sewed to the framework serves as a
flap to close the open end after the tree is dusted. For larger
trees tents made after the model of those used in California are
best. For smaller trees tents made in the form of a bag stiffened
by an application of parrafin and an iron hoop around the bottom
have been very' satisfactory and hate the :advantage' of being
A dust of calcium cyanide has been successfully used under
tents. If, however, too large a dosage is used or the humidity is
high, burning may result. Experiments are now in progress, in
cooperation with the American Cyanamid Company, to test out
the practicability of killing scale insects as well as aphids by this
method. Nicotine sulphate dusts can be safely used in any
weather and are effective except during a rain or cold, cloudy
weather. An exposure of from one to five minutes is sufficient,
half a day does no harm. These dusts will also kill rust mites
and scale crawlers. Red spiders require a longer exposure. Lady
beetles in all stages and syrphus fly larvae usually go thru with-
(To be Continued)
Now is the time to spray trees affected with rust mite,
scab or melanose. We handle the
DRY LIME SULPHUR
It saves freight on water and expense of handling. Ship-
ped in air-tight packages with removable top. Will keep
indefinitely if top is replaced after using. Dissolves readily
in any water. Add Dry Lime Sulphur to water and stir.
Five pounds to one hundred gallons water for rust mite,
equivalent to two gallons 330 Lime Sulphur Solution to
one hundred gallons of water. Prices range from 101/2 to
25c per pound according to quantity order.
Arsenate of Lead Carbolic Acid, Crude
Bordeaux Mixture Fish Oil Soap
Genuine Protexol Soluble Sulphur Compound
Caustic Soda Sulphur Flowers, etc.
Schnarr's Spray Formula Target Brand White Fly De-
Fresh stock of goods always on hand.
IN OUR SPRAYING DEPARTMENT
we carry only the best and most reliable, such as Leggett's
Champion Duster, Lowell Compressed Air Sprayers and
Gould Sprayers. Write for booklet and prices.
E. 0. PAINTER FERTILIZER CO., Jacksonville, Fla.