LIBRARY

268 COLLEGE ENTOMOLOGY
Pharynx - chief suction organ.
Gustatory organ - present in most forms - sensory cells communicating with
pharyngeal duct.
Mid-intestine or ventriculus - often divided into (1) anterior sac-like pouch;
(2) tubular section; (3) enlarged ovoid chamber; (4) narrower tubular
portion which is absent if there are no gastric creca.
Gastric cceca - present if narrower tubular portion is present; bacteria
reservoir: variable in number from none or few to several hundred.
Malpighian tubules - usually four but fewer occur.
Salivary glands - two- or many-lobed thoracic glands which may be very
large; piliform or sac-like accessory glands; ducts unite into single canal
emptying into salivary pump.
Odoriferous glands - characteristic of many species of bugs. Openings
located either laterally or at the middle of the metathorax near hind coxre.
Situated on the anterior dorsal margins of abdominal segments IV to VI
in the nymphs.
Circulatory System. Not greatly specialized.
Heart - five-chambered.
Pulsatile organs - present in legs of aquatic bugs.
Respiratory System. Well-developed system; tracheal trunks large.
Spiracles - variable in form and protective mechanisms; one pair on mesothorax,
one pair on the metathorax, and seven to eight pairs on abdominal
segments I to VII or I to VIII; usually located ventrally on the sides of
the abdomen.
Nervous System. A tendency towards condensation of the nervous centers;
according to Raandt (1878), (Imms, 1934), there may be: (1) one center in
Hydrometra,' (2) two ganglia fused together in NEPIDJE; (3) three ganglia:
infra-cesophageal, first thoracic, and abdominal ganglia in segments II
and III fused together.
Reproductive System. Variable, especially in the male.
Female - ovarioles - vary in number from four to seven.
Spermatheca - usually present and complex, may be a single organ or
small paired organs.
Accessory glands - globular or tubular; two or three in number.
Berlese organ - a copulatory pouch to receive spermatozoa and pass them
on to the ova in the CIMICIDJE.
Viviparity - pseudo-placental organs formed in the POLYCTENIDJE.
Male - testes - consisting of six follicles in a scrotum. Very little information
available concerning the male organs.