Official Organ of the Florida Entomological Society
VOL. XXI JULY, 1938 No. 2
A NEW FRANKLINIELLA (THYSANOPTERA) FROM
By J. R. WATSON AND J. R. PREER1
Frankliniella pontederiae n. sp.
FEMALE (macropterous) :-Length about 1.03 mm. (distended about 1.4
mm.). Color chestnut brown by reflected light, raw sienna by transmitted
light (Ridgway), almost uniform brown, thorax and anterior abdominal
segments with weak orange-yellow, hypodermal pigment; legs and antennae
lighter than body; tarsi almost colorless, occasionally clouded with brown
and a dark spot at the base of the apical segment. Wings, including setae,
practically colorless, body setae light brown; antennal segment II brown,
nearly as dark as the head; IV to VIII mouse gray, III somewhat lighter,
Head about 0.63 as long as greatest width, broadest across the eyes,
slightly narrowed posteriorly, cheeks slightly arched; inter-ocellar setae
long (about 56 microns), situated between the posterior ocelli; postocular
setae weak (about 16 microns long); other dorsal cephalic setae minute.
Eyes about 62 microns long, 42 wide, their interval about twice their
width, occupying somewhat over half the total length of the head. Ocelli
large, oval in outline (16 microns wide and 21 long), posterior pair situ-
ated somewhat behind the middle of the eyes and close to their margins,
bordered by narrow dark red crescents. Their interval a little over twice
their width. Antennae short and stout, about 2.6 times the length of the
short head; intermediate segments being especially short, segment II not
produced dorsally and without especially strong spines; segment III with
apical portion of pedicel slightly swollen; segment V short and broad,
narrowed very little distally, broadly joined to VI and only about 1.5 times
as long as broad; style almost as long as segment VI. Setae rather weak,
brown, paler and weaker apically. Mouth cone extending to posterior
border of prosternum.
Prothorax about 1.4 times as wide as long; major setae long, measur-
ing as follows in microns: antero-marginal 69, antero-angular 80, pair at
posterior angles 93, large sub-median pair on posterior margin 53; other
setae normal except the pair just posterior to the middle of lateral margins
which are much stronger (about 50 microns).
'Contribution from the Department of Entomology, Florida Agricultural Experiment
THE FLORIDA ENTOMOLOGIST
Fore wing with 23-27 setae on anterior margin, anterior vein with
usually a group of three followed by 13-14 fairly evenly spaced setae,
posterior vein with 10-12, all nearly colorless.
Abdomen of normal form and structure: tergum VIII with comb sparse
and weak, but complete; setae on segment X brown, long and strong;
tergum X divided for nearly three-fourths of its length.
Fig. 1.-(a) Head and prothorax of
Frankliniella pontederiae n. sp. 9 para-
type. (b) Right antenna.
Measurements of female (mostly holotype) in mm.: Head, length
.105, width .17; prothorax, length .15, greatest width (including coxae)
.23; mesothorax, greatest width .31; metathorax, greatest width .30; fore-
wings, length .82, width at middle .08; abdomen, greatest width .31; an-
tennal segments, length (width) in microns:-I, 34(37); II, 40(29); III,
48(24); IV, 39(24); V, 32(21); VI, 44(24); VII, 16(11); VIII, 24(6);
total .27 mm.
VOL. XXI-No. 2 19
MALE, length about .87 mm. (distended about 1.14) :-Much smaller
than the female and lighter in color, brownish yellow. Wings short, ex-
tending but little beyond the tip of the short abdomen, membrane often
shaded very light brown, fore vein with 14-16 setae, hind vein with 9-12,
abdominal sternites 3-7 each with a large oval semitransparent area.
Measurements of male (mostly allotype) in mm.: Head, length .08,
width .15; prothorax, length .13, greatest width .21; mesothorax, greatest
width .26; metathorax, greatest width .26; forewings, length .63, width
at middle .07; abdomen, greatest width .19; antennal segments, length
(width) in microns: I, 30(35); II, 37(27); III, 40(21); IV, 35(24); V,
27(19); VI, 37(22); VII, 13(10); VIII, 21(5); total .24 mm.
Fig. 2.--9th and 10th abdominal segments of
Frankliniella pontederiae n. sp. J paratype.
Nymphs a deep yellow color.
In general appearance, color and small post-ocular setae, this species
suggests fusca, but can be at once distinguished by the form and color of
the antennae and the wings and tarsi.
The strong seta on the lateral margin suggests Scolothrips but is much
shorter and stouter than in that genus and situated more posteriorly. It is
in the same position but stouter than the corresponding one in F. fusca.
Described from 14 macropterous females and 14 males. Collected by
the junior author on July 28, 1937, near Melbourne, Florida, and near Fort
Drum on August 12, 1937, from spikes of Pontederia cordata, and by the
senior author from the same host in Manatee County, on October 5, 1937.
Types in the collections of the authors.
Official Organ of the Florida Entomological Society
VOL. XXI JULY, 1938 No. 2
J. R. WATSON, Gainesville -...................-------------------Editor
E. W. BERGER, Gainesville--...-...--...---------..-.. Associate Editor
J. W. WILSON, Lakeland, Box 522-....-....----....- .. Business Manager
Issued once every three months. Free to all members of the
Subscription price to non-members is $1.00 per year in ad-
vance; 35 cents per copy.
THE GROSS ANATOMY OF THE DIGESTIVE AND
REPRODUCTIVE SYSTEMS OF
Naupactus leucoloma Boh.
A. N. TISSOT
On July 7, 1937 and again on July 20 the writer together with Pro-
fessor J. R. Watson and other entomologists visited the region of western
Florida and southern Alabama infested with the White-Fringed Beetle,
Naupactus leucoloma Boh. On both occasions the weevils were found in
considerable numbers on cotton and peanuts and to a lesser extent on some
other plants. A question arose concerning the sexes of the beetles and
whether or not there were any external characteristics that would enable
one to distinguish between them. All the specimens examined in the field
appeared to be alike and a large number of them were collected for further
study. After returning to Gainesville a few dozen specimens were dissected
and in every case were found to be females. Since then about 200 beetles
have been dissected and no males have been found. Parthenogenetic re-
production is rather common in the subfamily Otiorhynchinae to which this
weevil belongs. Ssilantjew (7)2 appears to have been the first to note
and report upon the occurrence of parthenogenesis in this insect group.
Palm (4) reports this method of reproduction in the Alfalfa Snout Beetle,
Brachyrhinus ligustici L. Smith (5) cites numerous references and men-
tions several species of weevils that are known to breed parthenogenetically.
The first few dissections revealed some interesting features of the
internal anatomy of this beetle. There appeared to be no publications
dealing with its anatomy and the writer decided to study the digestive and
reproductive systems with the thought of preparing a paper for publica-
tion. Bissell (1) and Snodgrass (6) have been followed rather closely
for the names of the parts of these two systems.
'Contribution from the Department of Entomology, Florida Agricultural Experiment
Station, Gainesville. Florida.
2Numbers in parentheses refer to Literature Cited.
VOL. XXI-No. 2 21
The specimens used for dissection were collected in the field on cotton
and peanuts. They were killed by dropping them alive into 70 percent
alcohol and they were kept in the same alcohol in which they were killed.
The integument of the abdomen is sufficiently thin to allow the infiltration
of enough alcohol to preserve the internal organs fairly well. In some
cases the thin-walled ventriculus was somewhat disintegrated and easily
broken up and in the older beetles with mature eggs, the calyces of the
ovaries were so distended and their walls stretched so thin that it was
very difficult to remove them without having them fall apart.
The Mouth Parts: The mouth of this beetle is situated at the apex of
the short, thick snout or beak. When the mandibles are removed the opened
end of the beak is seen to present four large V-shaped notches. The dorsal
and the lateral ones are of about equal width and depth but the ventral
one, the gular emargination, is much deeper than the others. There are
six well-defined mouth parts; a pair of mandibles, a pair of maxillae, the
hypopharynx, and the labium. The labrum is entirely lacking. The man-
dibles (Fig. 1) are the most prominent of the mouth parts. Each mandible
is a heavily sclerotized piece presenting a strongly convex external aspect
and having the posterior or inner face somewhat concave. The mandible
articulates with the head capsule along its lower posterior side. Posteriorly
within there is a broad face to which is attached the powerful muscle that
operates it. The anterior cutting edge is a broad curve with rather acute,
smooth margin without teeth. The cutting edge of one mandible overlaps
that of the other, fitting closely against its convex outer surface. When
the mouth is closed the left mandible usually overlaps the right. In 50
specimens chosen at random the left mandible overlapped the other in all
except three cases. Attached to the posterior inner face of each mandible
is a thin chitinous plate or curtain that extends back into the pharynx.
These probably serve to keep the pharynx open and to direct the food into
Rather frequently in newly emerged individuals, and more rarely in
the older ones, one or both of the mandibles bears on its anterior face
an accessory piece. This is a rather long and slightly curved process
that is supposed to be used by the freshly matured insect in cutting its
way out of the pupal case. These accessory pieces usually are lost soon
after emergence, their point of attachment being indicated by an irregular
scar on a slightly raised protuberance. The point of fracture appears as
a slightly impressed line which is shown as a dark line in the illustration.
This form of mandible with a cutting edge and accessory piece appears to
be contrary to the general rule for insects belonging to this subfamily.
Blatchley and Leng (2) referring to Horn (3) write: "According to Horn,
the form of the mandible itself, without reference to the scar, indicates
the occurrence of the deciduous piece. In those snout beetles, comprising
the great majority of Rhynchophora, which have the mandibles acute at
tip and one overlapping the other by an edge more or less acute, no decidu-
ous piece or scar will be found. But in those in which the mandibles meet
with a broad surface, and whose function is rather that of crushing than
of cutting, the scar may be expected." That the mandibles in this insect
22 THE FLORIDA ENTOMOLOGIST
R- v0 P 7
MC- SP SPV .MC
.- 0 7-O
VOL. XXI-No. 2
indeed function as cutting organs rather than crushing is indicated by the
food in the alimentary tract. An examination of this food discloses many
relatively large pieces with rather sharp-cut and angular margins that
show no evidence of crushing.
With the exception of the basal portion of the labium the rest of
the mouth parts lie within the concavity of the mandibles when these are
closed. The maxillae (Fig. 2) are rather fleshy and slightly sclerotized
organs. The most prominent features of the maxilla are the four-jointed
palpus and the large lacinia bearing four large chitinous teeth on its
posterior margin. The labium (Fig. 3) is reduced to three parts; the
three-jointed palpi being attached directly to the apex of the mentum
which, with the submentum, forms a roughly hexagonal plate. All vestige
of the suture between the mentum and the submentum has been lost and
the ligula is wholly wanting. The rather pointed anterior end of the hypo-
pharynx lies between the maxillae. It broadens posteriorly forming floor
of the buccal cavity. The hypopharynx is a soft and yielding organ, its
surface presenting a slightly roughened appearance.
THE ALIMENTARY TRACT
The digestive tract (Fig. 5) is approximately twice the length of
the body and varies greatly in diameter in its different portions. The
anterior half is relatively straight but the posterior half lies in coils
and loops. It is attached to the body wall at each end but for the rest
of its length lies free in the body cavity, being supported more or less
by tracheae and fatty tissue. Dorsally, the meso- and metathorax are very
short, the abdomen extending far forward toward the posterior margin of
the prothorax. The dorsal abdominal wall is membranous and it is prac-
tically impossible to determine the limits of the segments. When the elytra
are removed loops of the hind intestine and parts of the reproductive system
frequently are visible through the abdominal wall. In other cases these
organs are embedded in a mass of fatty tissue that hides them from view.
EXPLANATION OF FIGURES
Fig. 1.-Lateral view of left mandible with accessory piece intact. Cutting
edge to the left, X 26.
Fig. 2.-Mediad view of left maxilla, X 26.
Fig. 3.-Ventral view of labium, X 26.
Fig. 4.-Dorsal view of abdomen showing general arrangement of organs
visible when dorsal wall is removed, X 6.
Fig. 5.-Dorsal view with digestive system extended to show the different
parts, X 8.5.
Fig. 6.-Dorsal view of abdomen showing reproductive system, somewhat
diagrammatic, X 8.5.
Fig. 7.-Lateral view of posterior part of body showing part of repro-
ductive system, ovipositor retracted, X 12.
Fig. 8.-Lateral view of posterior part of body showing ovipositor ex-
tended, X 12.
A, anus; B, baculum; BU, bursa copulatrix; CO, common oviduct; CP, caecal pouches;
CR, crop; CY, calyx; EL, tip of elytron; GC, gastric caeca; M, mantle; MC, muscle cap;
MT, malpighian tubules; MU, muscle bands; 0, oviduct; OE, oesophagus; OP, ovipositor;
OT, ovarian tube; P, pharynx; PV, proventriculus; R, rectum; RS, rectal sac; SG, sperma-
thecal gland; SP, spermatheca; SPV, spiculum ventrale; ST, stylus; S5, fifth sternum;
TG, last abdominal tergum; V. vagina; VE, ventriculus.
THE FLORIDA ENTOMOLOGIST
The fore-intestine: This part of the digestive tract is a relatively
straight tube that widens posteriorly. Immediately behind the buccal
cavity the short pharynx (P) narrows posteriorly to the oesophagus. The
walls of the pharynx are light brown, slightly sclerotized with a roughened
surface. The oesophagus (OE) is a short thin walled transparent passage
that lies beneath the brain. Immediately behind the brain at about the
hind margin of the eyes the oesophagus joins the crop that suddenly dilates
to form a large storage chamber. The crop (CR) extends back through
the head and reaches nearly to the posterior edge of the prothorax. Except
for its tapering anterior end the crop is of rather uniform width. It usually
is filled with food and shows no foldings of its walls. The crop opens
into the nearly spherical gizzard or proventriculus (PV) that occupies the
region of the meso- and metathorax. Externally the gizzard is covered
with a layer of circular muscles. The muscle fibers are not continuous
around the circumference of the organ but are divided into eight sections.
The end of each section is attached to the edge of a longitudinal chitinous
plate that bears on its inner edge a comb-like structure composed of a great
many bristle-like chitinous teeth. These teeth all are inclined posteriorly,
those at the anterior end of the plates being longer than the rest. The
plates are arranged in eight pairs corresponding to the eight sections of
the circular muscles. The gizzard is attached to the ventriculus or stomach
posteriorly. Between these two parts of the tract is the cardiac or stomo-
daeal valve. This is essentially a muscular fold or ring attached to the
posterior end of the gizzard and projecting into the ventriculus.
The mid-intestine: The stomach or ventriculus (VE) is the widest
part of the alimentary tract. Its anterior portion is a large pear-shaped
structure that occupies the anterior part of the abdominal region and
rests directly on the ventral wall. The ventriculus is a thin walled organ
whose surface consists of numerous protruding caecal pouches (CP) with
deep constrictions between them. Within these constrictions lie many loops
of the malpighian tubules. Postero-ventrally the ventriculus is attached
to the much narrower second portion of the mid-intestine. This lies in
a rather tight close spiral on the floor of the abdomen. This narrowed
portion of the intestine exhibits three distinct regions of approximately
equal length. The first is smooth except for a slight wrinkling due to its
tightly coiled position. The middle portion bears numerous finger-like
gastric caeca (GC) and the third portion is smooth-walled. The posterior
end of the mid-intestine is indicated by the point of attachment of the
The hind-intestine: This portion of the tract is divided into three
well-defined regions. A short distance behind the point of origin of the
malpighian tubules is a very abrupt constriction, the pyloric valve. Follow-
ing this is a region of rather uniform width. Its walls are thin and trans-
parent, the food material within being clearly visible. The anterior part
of this region forms a close S-curve that lies against the posterior wall
of the ventriculus. Following this curved section is a straight portion
that extends antero-dorsally to the front of the abdomen. At this point
the tube bends sharply back on itself and here the malpighian tubules re-
enter the intestine wall. The next portion is termed the rectal sac (RS)
by' Snodgrass. It extends posteriorly and lies close to the dorsal wall,
VOL. XXI-No. 2
usually being visible when the elytra are removed. It broadens posteriorly
then is abruptly constricted. This constriction marks the beginning of
the rectum. The rectal sac is covered with a thick layer of longitudinal
muscle and when it is not distended with food its walls show some longi-
tudinal folds. The rectum (R) is of nearly uniform width being much
narrower than the rectal sac. The rectum opens posteriorly at the anus
(Fig. 8A). The anal opening is situated above the ovipositor and beneath
a shield-shaped plate that Bissell (1) terms the mantle (M). This may
represent the last abdominal tergum though the one labelled (TG Figs.
7 and 8) is the last one bearing a spiracle.
The malpighian tubules: The six malpighian tubules (MT) of this
beetle are extremely long and slender and they lie in numerous loops and
convolutions. At their point of origin they are always attached in a
definite pattern. Four of the tubes arise in a group on one side of the
intestine and the other two arise together on the opposite side. Due to
their very delicate structure and their manner of twisting around and be-
tween the alimentary tract and the reproductive organs it is extremely
difficult to dissect out a complete and unbroken tubule. In the few instances
where this was accomplished the tubules were found to be much longer
than the entire alimentary tract. At their origin the tubules are attached
to the intestine wall at an acute angle anteriorly. Two of the tubules lie
for most of their length in loops and convolutions between the rectal sac
and the vagina. The other four meander about, reaching all parts of the
abdomen. For much of their length they twist about the ventriculus, lying
in the constrictions between the caecal pouches. All the tubules finally
reach the same point and reenter the intestinal wall at a short distance
before the beginning of the rectal sac. The proximal portion of the tubules
is wider and apparently thicker walled than the distal portion.
The salivary glands: Each salivary gland is a long, delicate, thread-
like tube that loops about in the side of the head, lying above the powerful
mandibular muscles. The opening into the mouth cavity is at a point near
the base of the maxilla.
Males of this insect have not been found and apparently it is able
to maintain itself by parthenogenetic reproduction. However, certain
features of the reproductive system, particularly the presence of a sperma-
theca and copulatory pouch indicate that males may occur at times.
In the young newly emerged females the reproductive system consists
of rather slender tubes that lie in numerous loops in the abdomen. In the
older beetles that are ready to begin laying eggs, portions of the tubes
are very much distended and tightly packed with relatively large oval
eggs. In this condition the tubes are considerably distorted and occupy
a considerable portion of the abdominal space.
The ovaries: In the anterior portion of the abdomen just beneath
the dorsal wall there lie two pairs of tubes that Snodgrass (6) terms the
ovarioles and that Bissell (1) terms the ovarian tubes (OT). The two
tubes of each side constitute an ovary. At their anterior extremities the
two ovarioles of each pair are joined together by a short slender filament.
Though the apices of the two pairs of ovarioles sometimes lie close together
THE FLORIDA ENTOMOLOGIST
along the median line of the body there is no connective between them and
neither is there any connection to the body wall. The ovarioles lie em-
bedded in a mass of fatty tissue that supports them. Each ovariole is
enclosed in a thin membranous envelope. The ovarioles extend diagonally
toward the sides of the abdomen and constrict rather sharply into the
oviducts. In the younger beetles the oviducts (0) are slender tubes that
lie in close irregular loops at the sides of the abdomen and lead downward
toward the ventral wall. The oviducts of each side unite to form a single
tube termed the calyx (CY). The two calyces unite to form the common
oviduct (CO). In the older beetles the upper parts of the oviducts show
rather regular expansions and constrictions indicating the presence of the
developing eggs. In the lower parts of the oviducts there are larger, more
nearly mature eggs and in the calyces are fully developed eggs. The walls
of the calyces are very greatly distended and distorted and have lost all
resemblance to their former condition. The junction of the two calyces
lies close to the ventral abdominal wall and from this point the common
oviduct leads dorsally and anteriorly and then curves sharply backward
to enter the genital chamber or vagina.
The genital chamber and the ovipositor: Slightly to the right of the
median line of the posterior portion of the abdomen lies the vagina (V)
and its extension the ovipositor (OP). These structures lie close to the
dorsal wall and often are visible when the elytra are removed though in
some cases they are concealed by fatty tissue. The vagina is a short pouch-
like structure that receives the common oviduct at its anterior end. It
tapers into the ovipositor posteriorly. Extending forward from the dorsal
anterior end of the vagina is a flattened thin-walled chitinous pouch, the
copulatory pouch or bursa copulatrix (BU). The walls of the vagina are
chitinous and have a great many longitudinal folds that allow for expansion
and the passage of the eggs. The vagina and the brusa are completely
covered with a thick muscular layer. Surrounding the anterior end of the
vagina is a large mass of muscle tissue that for want of a better name
may be termed the muscle cap (MC). This simply fits around the end
of the vagina and is not very firmly attached to it, the two being separated
very easily. The ovipositor is a long thin-walled tube that is continuous
with the body wall. It is capable of being extended far beyond the end
of the body and telescopes into itself and may be retracted completely
within the abdomen. Beneath the ovipositor in its retracted position is
a heavy, slightly curved, chitinous rod the spiculum ventrale (SPV). The
anterior end of the spiculum is embedded in the muscle cap and its posterior
end widens into a spoon-shaped structure. Surrounding the ovipositor are
heavy longitudinal muscles. Anteriorly these muscles attach to the muscle
cap and posteriorly to the body wall. The contraction of these longi-
tudinal muscles draws the vagina and oviduct backward and straightens
the curve of the common oviduct. The spiculum ventrale lends stiffness
to the ovipositor and forces it out of the body. The apical part of the
ovipositor is supported and strengthened by two longitudinal ribs or baculi
(B). Each baculum bears on its posterior half a row of short spines
that are inclined slightly forward. On each side near the apex of the
ovipositor is a somewhat oval chitinous plate bearing a number of fine
VOL. XXI-No. 2
short spines. At the very tip of the ovipositor is a pair of short thick
styli (ST). Each stylus bears four or five short spines at its apex.
The spermatheca: Often when the dorsal abdominal wall is removed
a small dark brown object is visible to the right of the middle. This is
the spermatheca (SP) or receptaculum seminis. The spermatheca is a
sickle-shaped structure with the handle end of the blade much broadened.
Its walls are somewhat heavily sclerotized and though thin are fairly rigid.
Two ducts enter the spermatheca at the thickened end in the position corre-
sponding to the handle of a sickle. The duct nearest the end leads to the
vagina. It does not enter directly into the vagina but enters the wall
of the common oviduct at about its middle and runs along in the oviduct
wall to its point of entry into the vagina. This spermathecal duct is a
thin-walled chitinous tube that has a rather heavy covering of muscle or
connective tissue. The other duct entering the spermatheca is the sperma-
thecal gland (SG). This gland consists of a narrow chitinous tube lying
in an outer envelope of thick-walled tissue. The cavity of the sperma-
theca is filled completely with a mass of white material, probably the
product of the spermathecal gland. When observed under the high power
of the microscope this material presents a somewhat granular appearance.
(1) BISSELL, THEO. L. 1937. Structure of the Reproductive System of
the Pecan Weevil (Curculionidae). Ann. Ent. Soc. Amer., 30:
242-251, 2 plates.
(2) BLATCHLEY, W. S. and LENG, C. W. 1916. Rhynchophora or Weevils
of North Eastern America.
(3) LECONTE, JOHN L. and HORN, GEORGE H. 1876. The Rhynchophora
of America North of Mexico.
(4) PALM, CHARLES E. 1935. The Alfalfa Snout Beetle, Brachyrhinus
ligustici L. Cornell Agr. Exp. Sta., Bul. 629, p. 9.
(5) SMITH, FLOYD F. 1932. Biology and Control of the Black Vine Weevil.
U.S.D.A., Tech. Ser. Bul. 325, pp. 20-21.
(6) SNODGRASS, R. E. 1935. Principles of Insect Morphology.
(7) SSILANTJEW, A. A. 1905. Uber Einen Sicher Konstatierten Fall der
Parthenogenese bei Einen Kafer (Otiorhynchus turca Bohem.).
Zool. Anz., 29: 583-586.
Index to Florida Entomologist, Vols. I to XIX inclusive .. $ .75
Volumes I to XX Florida Entomologist --......................---- .... 21.75
Back Numbers of the Florida Entomologist (single No.) .... .35
Series of papers on systematic subjects such as Blatchley's
papers on Coleoptera of Florida, Professor J. R. Watson's papers
on Thrips and other systematic papers can be furnished.
Orders should be sent to J. W. Wilson, Business Manager,
2613 Coventry Drive, Lakeland, Florida.
THE FLORIDA ENTOMOLOGIST
NOTES ON PAMERA POPULATIONS ON VARIOUS TYPES
OF PLANT COMMUNITIES IN THE VICINITY
OF PLANT CITY
By J. W. WILSON
Three species of pamera, Orthaea longulus (Dallas), O. vincta (Say)
and 0. bilobata (Say), are found on strawberry plants and other vegeta-
tion which forms a heavy growth near the ground in the strawberry grow-
ing section near Plant City. Of the three species 0. bilobata is by far the
most abundant. Determinations were made by Miss K. V. Wheeler by
comparing identified specimens in the department collection at Gainesville.
A study of the pameras was begun to determine host plants, where and
how they pass through the summer and if possible why the pameras occa-
sionally become abundant enough to cause considerable damage. In previous
years various workers have observed that heavy pamera infestations are
correlated with hot, dry winters. For example, the heaviest, infestation
observed in the Plant City section occurred during 1931. Table 1 gives
the temperature and rainfall for the winter months of 1931-32 with the
ten year average temperature and rainfall for these months as recorded
at the Strawberry Laboratory, Plant City.
Temperature, F. Rainfall, Inches
Month 10 yr. 10 yr.
1931-32 1937-38 Ave. 1931-32 1937-38 Ave.
November 70.3 64.0 66.7 .03 3.56 1.31
December 72.3 59.8 62.1 1.26 1.10 1.88
January 67.4 59.3 63.1 .93 1.49 | 2.18
February 70.6 65.8 64.5 .22 .72 I 2.45
March 62.8 71.4 65.4 3.87 1.96 3.95
It readily can be seen from this table that the temperature for all of
the months of 1931-32 except March were higher than the average and the
rainfall except for March was lower. Moreover, during the winter months
of 1937-38 the temperatures were average or below for all months except
March, while the rainfall for November was high, and below average the
remaining months. The infestation of pameras began building up during
February and March as is indicated in Table 2.
In Table 2 the various types of vegetation from which samples were
taken are given. During November, December and January when the
strawberry plants were small with few dead lower leaves, no pameras were
observed on the strawberry plants with one exception. Two fields in which
straw had been placed to protect the plants from frost were examined as
well as a number of fields in which straw had not been used. At the begin-
ning it was planned to watch these two fields closely to see if pameras
appeared in them before they did in fields where straw was not used. Due
to interference of other work these observations could not be continued
after January 4th. The exception mentioned above was a field about 14
VOL. XXI-No. 2
miles northwest of the laboratory in which, on December 30th a small
number of pameras were observed. The plants in this field were about
eight inches across while most of those in other fields were about four
inches across. No further observations were made in this field also due
to the interference mentioned above.
TABLE 2.-Counts of pamera population (nymphs and adults) on vari-
ous types of vegetation. Previous to January 14th the counts were made by
the author. Twenty sweeps of the net were taken as a unit, in some cases
more than one unit count was made on the same vegetation. In these cases
each unit is shown under the numbers (example, green bermuda, under
some dates 3 unit counts were made and recorded as count 1, 2, and 3.)
The count of January 14th and subsequent counts were made by the labor-
atory technician who merely swept over approximately the same territory
0 0 2 6
1 1 0 0
"~ I z ^
1 2 3 4 5
THE FLORIDA ENTOMOLOGIST
In addition to the low temperatures experienced during November,
December and January 1937-38 environmental conditions in the strawberry
fields were poor for a heavy infestation of pameras. August, September
and October were very dry months which delayed the transplanting of the
strawberry plants from the nursery to the field. As a result the plants
grew poorly. The early cold periods in November further retarded the
growth of the plants to the extent that plants were generally far below
the normal size.
It appears from observations made during the recent months that
pameras may be found on almost any low growing vegetation that covers
the ground well; and that they pass the months when there are no straw-
berry plants on such vegetation. Migration to the strawberry plants takes
place when the plants attain sufficient size to furnish the proper environ-
mental conditions and heavy infestations of the pameras are directly in-
fluenced by the temperature and rainfall.
During the first part of November adult and nymphal pameras with
a few specimens of adult Geocoris punctipes (Say) were placed in a lantern
globe cage over a strawberry plant. From an adult G. punctipes a parasitic
fungus which also attacks pameras was isolated. Dr. A. N. Brooks made
cultures of this fungus some of which were sent to Mr. Erdman West,
Mycologist of the Florida Agricultural Experiment Station, and to Miss
Vera K. Charles of the U. S. Department of Agriculture. Mr. West placed
the fungus in the genus Beauveria and Miss Charles identified it as being
B. bassiana (Bals.) Vuill.
Here again cool moist conditions are favorable to the development
of this fungus and the fungus may play an important part in preventing
the development of an abundant population of the pameras when these
SERICOTHRIPS LANGEI MOULT. IN FLORIDA
By J. R. PREER
On April 16, 1938, at Lake Bryant, Marion County, Florida, a series
of thrips was taken from the leaves of Nymphaea by the author. Of the
fifteen all but one proved to be Sericothrips langei Moult., the other being
S. langei tissoti Wats. The species was described by Moulton in 1929
from three females taken at a lake in Illinois. Watson described the vari-
ety from Alachua County, Florida (FLORIDA ENTOMOLOGIST, Vol. XX, No. 1,
pp. 2-3, 1937). The above collection thus extends the range of the species
to Florida and also bears out the conclusions of Watson and Moulton that
the form described by Watson should be given varietal instead of specific
rank and verifies the conclusion drawn as to the host plant. The variety
is distinguished from the species by the complete absence of the dark,
distal, transverse band on the fore-wings of the female and its reduction
in the male. The description of the male of S. langei Moult. will be pub-
lished at a later date.