IV. IXSECTA: HEXAPODA, APHAXIPTERA 



431 



Nemocera in their long proboscis and in development. The larvae and pupae 

 live in damp places or in water and move rapidly, the larvae having biting mouth 

 parts. Black flies, SIMULIHXE, excel the mosquitos in viciousness; the horse 

 flies, TABANIDJE. Sub Order III. MUSCARI/E (Brachycera). Body short, 

 stout; antennae three-jointed with a bristle (arista) (fig. 485); legs short, ending 

 in an adhesive organ (pulvUlus); larvae headless, living in decaying substances 

 or parasitic in other animals. MUSCID^:; house flies (Musca domestica* and 





FIG. 485. FIG. 486. 



FIG. 485. Left, Erax bastardi, robber fly; right, antenna of Muscid showing 

 arista at a. 



FIG. 486. Gastrophilus equi* hot fly (from. Hajek). h, halteres. 



other species), blow fly (Calliphora vomitoria*), the flesh fly (Sarcopliaga car- 

 naria,* viviparous). Many Muscidae convey disease, the house fly carrying the 

 germs of typhoid fever on its feet, while the tropical species of Glossina are 

 responsible for the nagana disease of cattle and horses and for the sleeping 

 sickness of man (p. 184). ASILID^;, robber flies (fig. 485) prey on other insects, 

 as do some SYRPHID^;: Eristalis* CEsTRiD^:, bot flies; the larvae always 

 parasitic; those of the sheep bot (CEstms ovis*) in the frontal sinuses of the 

 sheep, those of the ox warble (Hypodcrma lincatti*) just beneath the skin of 

 cattle; those of Gastrophilus equi* (fig. 486), in the stomach of horse. In the 

 tropics Dermatobia noxialis lives as a larva in the human skin. Sub Order IV. 

 PUPIPARA. Very active, often wingless forms living as parasites on mammals 

 and insects; larval development inside the mother; pupation occurring soon 

 after birth. Mehphagus ovinns* sheep tick; Braula c&ca,* bee louse. 



Order X. Aphaniptera (Siphonaptera) . 



In spite of the lack of wings the fleas are closely related to the Dip- 

 tera, since they have doubtless descended from winged forms, as they 

 have a holometabolous development. The larvae, 

 long and footless, live in decaying wood or dust 

 in cracks in the floor, etc., and give rise to pupae, 

 both without traces of wings. Yet fleas and flies 

 differ in that fleas have similar body somites and 

 lack the haustellum, the sucking tube being formed 

 of labrum and mandibles, while the sharp maxilla- 

 puncture the skin. Besides Pulex irritans* the 

 flea that attacks man, many other species occur 

 on other animals. Fleas are now known to carry diseases, among them 

 the bubonic plague. In warm countries the jigger or chigoe, Sarcopsylla 



FIG. 487. Pulex irri- 

 tant* flea (from Blan- 

 chard). 



