5C8 



INSECTA. 



rudimentary biting mouth parts, an indistinctly segmented thorax, 

 and an abdomen which usually consists of nine segments. 



Fam. Pediculidse. Lice. With fleshy proboscis-sheath armed with recurved 

 hooks, protrusible suctorial tube, and two protrusible knife-like stylets. The 

 antennas have five joints. The feet, which are adapted for clinging, have 

 hooked terminal joints. The eyes are small and not facetted. The animals 

 live on the skin of Mammalia, and suck their blood, and lay their pear-shaped 

 eggs in the roots of the hair. The young, when hatched, do not undergo a 

 metamorphosis, and the louse which infects the human head, is fully developed 

 and capable of reproduction in eighteen days. Pediculug caj>itis Deg. Head- 

 louse of man. P. vestimenti Burm. (larger and of pale colour). Phthirius 

 pubis'L. (fig. 471). 



Fam. Mallophaga (Anoplura) (Pelzfresser). Lice-like in form, with tbrce- 

 to five-jointed autennre, and biting mouth parts, no fleshy proboscis, but a sort 

 of suctorial tube. They live on the skin of Mammalia and Birds, and feed on 

 young hairs and feathers, but also on blood. Trichodectes cants Deg. Philopterus 



Fio. 471. Phthirius pubit (after Landois) St, Stigma; 

 Tr, Trachea. 



anseris Sulz. Menopon 

 Nitsch, M. pallidwn 

 Nitsch, on fowls. 



Sub-order 2. Phy- 

 tophthires. * Rhyn- 

 chota with two pairs 

 of membranous wings. 

 The female is usually 

 apterous. The surface 

 of the skin is very 

 often covered with a 

 dense waxy deposit, 

 the product of cuta- 

 neous glands which 

 are placed in groups beneath warty prominences of the segments. 



Fam. Coccidae (Schildlause). The large females have a shield-shaped body, 

 and are wingless. The males are much smaller, and have large front wings, 

 and sometimes also rudimentary hind wings. The fully-developed males 

 have no proboscis or piercing weapons, and do not take in nourishment, 

 while the unwieldy, often unsymmetrical females, which may even have lost 

 the segmentation, insert their long rostrum into the parenchyma of plants and 

 remain motionless. The eggs are deposited beneath the shield-shaped body 



* C. Bonnet, "Traite d'Inscctologie," Tom. I.. Paris 174.". 



J. F. Kyber," Erfahrungen und Bemerkungen Uber die Blattlause." Ger mar's 

 Magaz. der Entomol. Tom. I., 1815. 



J. H. Kaltcnbach, " Monographic dcr Familie dcr Pftanzenlause." Aachen, 

 1843. 



R. Leuckart, " Die Fortpflanzung der Rindenlause." Archie fiir Naturgesch., 



1859. 



