HOW TO KNOW THE INSEQS 



Fig. 221. P'norocera clarlpennls 

 L'elg. 



Black, with metallic bluish 

 sheen. Head and thorax with gray 

 hairs. Scutellum brovm. Squamae 

 whitish, prominent. Length about 

 8 mm. (From U.S.D.A.) 



This Is one of our most helpful 

 families of files. The family Is 

 a large one. Its members are 

 parasitic on other Insects, many 

 Figure 221. of them destroying caterpillars. 



It Is a very common sight to find 

 the adults busily flying through 

 loiv plants searching for victims on v;hlch to deposit an egg. 

 21b Metascutel lum weak or absent, or if developed there is only 



hair (no bristles) on the hypopleura 22 



22a Oral opening and mouthparts very small; scutellum very 

 short. (The Bot Flies.) Fig. 222. 



Fami ly 87, OESTRIDAE 



Fig. 222. Hypoderma lineata De Vill. The 

 Ox Warble. 



Hairy. Black with bands and markings of 

 pale yellow. Larvae mature under skin of 

 cattle. Length 12-14 mm. (From U.S.D.A.) 



The fsunlly contains oiily a very few 

 species, all of which are parasitic in the 

 larval stage on mammals. 



Figure 222. 



22b Oral opening and mouthparts of normal size 23 



23a Hypopleura with a row of bristles 24 



23b Hypopleura with fine short hairs or bare, oral vibrissae 

 present. Fig. 223. 



Fami ly 74, MUSCIDAE 



Fig. 223. Stomoxys calci trans L. 

 The Biting House Fly. 



Black and gray. Rather closely 

 resembles the house fly. Common 

 about stables and domestic animals. 

 Bites viciously (a). Length 6-7mm. 

 (From U.S.D.A.) 



The family Ivluscidae as here de- 

 fined by the key Is as set forth by 

 Curran in his recent "North Ameri- 

 can Diptera," and would include many 

 species placed with other families 

 by earlier writers. The group in- 

 cludes many serious pests of plants 

 as well as of animals. 



Figure 223. 



105 



