ORDER DIPTERA. 



131 



Family Sarcophagidae. Bristle of the antennae plumose or hairy, 



with the apex bare. First 

 posterior cell only slightly 

 opened or else closed; tegu- 

 Ise large; legs stout. Sar- 

 cophaga carnaria Linn., the 

 flesh-fly of Europe, is black, 

 with the thorax streaked 

 with gray, and the abdomen 

 checkered with whitish; it 

 is viviparous, the eggs being 



hatched before they are laid. 

 FIG. 154. Sarcophaqa sarracemce. c, fly; a, o TTI 



larva; 6, pupa-case : d, g, head ; e. end of " sarracenm Rlley. 

 body; /, spiracle of larva; i, antenna; h, Family Tachinidee. Bristle 

 foot of fly.-After Riley. o f the antennae bare, or with 



a very short pubescence; thorax short; first posterior cell closed 

 or only slightly opened; legs short. Larvae parasitic in caterpillars 



FIG. 155. Tachina fly, and larva. 



and other insects, living on the fat and juices of their host; many 

 injurious caterpillars being destroyed by these useful flies. 



Family Dexidae. The species differ from those of the Tachinidae 

 in having the bristle of the antennae either pubescent or plumose; 

 and from the Muscidae in having the abdomen bristly above. Dexia 

 anaJis Say. 



Family (Estridae. Antennae inserted in rounded pits; the middle 

 part of the face exceedingly narrow; the opening of the mouth very 

 small; the mouth-parts rudimentary. Larvae usually very thick, 

 with a spiny skin. The ox bot-fly (Hypoderma bovis De Geer) appears 

 from June to September, the worms occurring during May and in 

 the summer in tumors on the backs of cattle, until in July they fall 

 to the ground; they remain in the pupa-case 26-80 days. The mag- 

 gots of the horse bot-fly (Gastrophilus equi Fabr.) hang by their 

 mouth-hooks to the walls of the horse's stomach. 



Family Platypezidae. Antennae with an apical bristle; hypopygium 

 symmetrically turned under the abdomen; middle tibiae with spurs; 

 empodium wanting. Platypeza anthrax Loew. 



Family Pipunculidae. Small flies with the head almost entirely oc- 

 cupied by the eyes; face very narrow. Pipunculus cingulatus Loew. 



Family Conopidse. Wasp-like, with a long abdomen; eyes broadly 

 separated; proboscis much prolonged; third joint of the antennae 



