LIBRARY

THYSANOPTERA 251
IMPORTANT ANATOMICAL CHARACTERs-eontinuea
External
dibles - stylet-like. only the left one
developed: maxilhe - side plates with
one or two sty lets and two- to eightsegmented
palpi; labium - broad and
short; ligula - very small with two
minute paragloss.re; palpi - one- to
four-segmented. The arrangement of
the mouth cone is: Exterior: labrum in
front; maxi11::e on sides; labium behind.
Interior: left mandible elongated,
piercing; right mandible rudimentary;
three stylets associated with
bases of maxillce and hypopharynx.
Sucking pump in head chamber.
Thorax - Pro thorax - usually free,
longer than either the meso- or the metathorax.
Meso- and metathorax - fused.
Legs - small, similar, or fore pair en·
larged. Tarsi - one- or two-segmented;
aborted; often with protrusible
vesicle or hoof-like enlargement at
apex and with single or paired claws;
spurs absent or present on the femora
and tibire, and tarsi.
Wings - absent, greatly reduced or two
pairs present; long and narrow; simi­
Jar; small anal area usually present;
few or no veins; veins often spined;
long hairs or spines closely set around
margins; folded flat over abdomen.
fringe folds closely along the wings SO
that the insects may appear wingless.
Spiracles - usually two pairs - one
pair each on the mesothorax and metathorax
(pair on the latter may be absent
in some forms).
Abdomen - normally lO-segmented, some
with a very small 11th segment; basal
segment closely attached to thorax;
posterior segment tubular in TUBULI­
FERA.
Spiracles - one pair each on abdominal
segments I to VIII inclusive.
Cerci - absent.
Genitalia - in the male, complicated.
Ovipositor - sickle-shaped, senate.
exserted between sternites VIII
and IX in TEREBRANTIA, absent
in TUBULIFERA.
Internal
Nervous System.
The brain, subresophageal ganglion and
prothoracic ganglion fused to form the
anterior nerve center; the meso- and
methathoracic ganglia are separate; abdominal
ganglion in segment r only;
median abdominal nerve cord.
Reproductive System.
Male-
Testes - fusiform, one pair.
Vasa deferentia - short.
Ejaculatory dUct - swollen anteriorly
where it receives ducts of one or two
pairs of large accessory glands.
Female-
Ovaries - short panoistic ovarioles.
Receptaculum setninis - present.
.Accessory glands - present.