HOW TO KNOW THE INSEQS 

 KEY TO THE MORE COMMON FAMILIES OF THE ORDER DIPTERA 



1a Coxae close together, often touching. Abdominal segments 

 showing. Wings usually present 2 



1b Wings absent or much reduced. (Some less common species 

 winged but coxae always widely separated.) (The Bird Parasite 

 Files.) Fig. 199. Family 81, HI PPOBOSCI DAE 



Fig. 199. Melophagus ovlnus L. 



Reddish brown, covered with long bristly 

 hairs. Altogether too common on shoep and 

 lambs. Length 5-6 mm. 



The members of this small family are curious 

 creatures, scarcely resembling files. The 

 larvae are full grown when born and Immedi- 

 ately pupate. Some species are winged. One 

 of these Is rather common on owls and hawks. 



Figure 199, 



2a Antennae with six or more free moving segments. (Usually 

 8 to 16) 3 



2b Antennae with not more than five free moving segments; 



often with only three segments but the third frequently ringed 

 or bearing a large bristle, or both 8 



3a Suture between the pro- and mesothorax V-shaped, (a) Usually 

 medium to large, loosely jointed, long-legged flies. (Crane 

 flies) Fig. 200. Family 4, TIPULIDAE 



Fig. 200. Tlpula angustlpennls Lw. 



Head and thorax brownish gray; 

 abdomen orange yellow with mid- 

 dorsal stripe black. Wings smoky, 

 with one dark brown and several 

 whitish patches. Length 19-25 mm. 



A large family of mosquito shaped 

 files. They are usually much larg- 

 er than mosquitoes but some are 

 very small. Their long legs are so 

 fragile that It Is a perplexing 

 problem to mount and keep a collec- 

 tion of this family. They are 

 most abundant In damp places. The 

 larvae of some species are Injur- 

 ious to grass crops. 



Figure 200, 



3b Thorax without V-shaped suture * 



4e Veins and margins of wings fringed with scales. Six longi- 

 tudinal veins reaching the margin of wing. (The Mosquitoes) 

 Fig. 201. 



Family 13, CULICIDAE 



97 



