IV. INSECTA: HEXAPODA, APHANIPTERA. 



493 



they were formerly united) in the short stout bodies, short antennae and 

 legs. They are distinguished from them and resemble the 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. Here belong the black flies, SIMULIID.E, which excel the mosquitos 

 in their viciousness, and the horse flies, TABANHLE, the females of which 

 attack cattle and men, as well as horses, with their painful bites. 



Sub Order III. MUSCAKL/E (Brachycera, after removal of Tanystoma). 

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

 532) ; legs short, ending in an adhesive organ (pulvillus) ; larvae headless 



FIG. 532. FIG. 533. 



FIG. 532. Left, Erax bast unit, robber fly ; right, antenna of Muscid showing arista 



at a. 

 FIG. 533,Gastrophilus equi,* bot fly. (From Hajek.) 7i, halteres. 



living in decaying substances or parasitic in other animals. The Mus- 

 CID^E include the house ft\e&(Muscadomestica* and other species), the blow 

 fly (Calliphora vomitoria *), and the flesh fly (Sarcophaga carnaria*), which 

 is viviparous. The ASILID.E, or robber flies, prey on other insects, as do 

 some of the SYRPHHLE : Eristfilis* of this family has an aquatic 'rat- 

 tailed larva,' one end being drawn out into a long breathing tube. 

 <ESTRID^E, bot flies ; the larvae always parasitic ; those of the sheep bot 

 ((Estrus ovis*) in the frontal sinuses of the sheep, causing the disease 

 called 'staggers'; those of the ox warble (Hypoderma lineata*) just 

 beneath the skin of cattle ; those of the horse (GastropMlus equi* fig. 

 533) in the stomach of the horse. In the tropics Dermatobia noxidlis 

 lives MS 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. 

 Nelopliagus ovinus,* sheep tick ; Braula cceca* 

 bee louse. 



Order X. Aphaniptera (Siphonaptera). 

 In spite of the lack of wings the fleas are 

 closely related to the Diptera, since they 

 have doubtless descended from winged forms, 

 as is shown by the fact that they have a Fm. 534. Puiex irritant* 



, , ,11 -in mi i flea - (From Blanchard.) 



holometabolous development. The larvae, 



long and footless, live in decaying wood or dust in cracks in the 



