132 



ENTOMOLOGY. 



with an apical style or a thick dorsal bristle; parasitic in the ab- 

 domen of wasps and bees. Conops tibialis Say. 



Family Syrphidae. — A spurious longitudinal vein between the third 



Fig. 156. a Fig. 157. 



Fig. 156.— Bot-fly of the ox. a, larva. Fig. 157.— Horse bot-worm, enlarged. 



and fourth longitudinal veins; first posterior cell closed; no depres- 

 sion in the face for the antennae. Often wasp- or beedike in shape 



Fisr. 159. Fig. 160. 



Fig. 158.— Rat-tailed pupa-case of Eristalis. 

 Fig. 150.— Merodon vosiicata. a, its pupa-case. 

 Fig. 160. — Syrphus (Mesograpta) politus, and Aphis-maggot, natural size. 



and coloration (Williston). The larvae of many species devour 

 Aphides, etc., and may be observed among their colonies. The 

 larva of Eristalis, which lives in stagnant, brackish, or excremen- 

 titious water, breathes by a lung caudal filament. 



Sub-order 3. Orthorhapha. — In this group the pupa is 



usually free, not coarctate, and escapes from the larval skin 



