240 



ECONOMIC ENTOMOLOGY 



D. Abdomen slender; wings narrow; antennae pulmose in 

 the males; wing veins strong near costal margin. — Chiro- 

 nomidce (Midges), p. 252. 

 DD. Abdomen short and thick; wings broad; antennae short 

 and non-plumose. — Siniuliida (Black Flies), p. 251. 

 Chief Families of the Brachycerous Orthorrhapha (Figs. 146-149); 



A. Antennae of five or more segments, those beyond the second more or less 

 united. (Fig. 144, E). 



Fig. 145. — Venation of a tipulid 

 {Tipida). (After Comstock.) 



Pig. 146. — Venation of a tabanid 

 {Tabanus). {After Comstock.) 



AA. 



B. Alulets large, third joint of antennae without a style or bristle. — 

 Tabanidce (Horse Flies), p. 252. 

 BB. Alulets small; branches of Radius crowded together near the costal 



margin.- — Straliomyiidce (Soldier Flies). 

 Antennae of four or five segments but the third joint not ringed. 

 B. Antennae long, clavate, 4- jointed; branches of Radius curving toward 

 costal margin. — Midaidce (Midas Flies). 



Fig. 147. — Venation of Dixa. {After 

 Comstock.) 



Fig. 148. — Venation of an asllid 

 {Erax). {After Comstock.) 



AAA. Antennae of three segments; Radius four-branched. 



B. Vertex of head hollowed out between the eyes; palpi present. — 

 Asilidcc (Robber Flies). 

 BB. Vertex of head not hollowed out; alulets small; beak prominent. — 

 Bombyliidce (Bee Flies). 

 Chief Families of the Cyclorrhapha (Figs. 151 and 152): 



A. Adults non-parasitic; maxillae covered by upper lip; Radius 3-branched. 



B. With a spurious longitudinal vein between Radius and Media; front 

 convex between the antennae. — Syrphidce (Flower Flies), p. 250. 



