CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 239 



ORDER DIPTERA (FLIES) 



Sub-orders and Groups 



A. Adults without a frontal lunule; pupa and adult escape from larval skin 

 through a T-shaped opening at anterior end. — Sub-order Orthorrhapha. 

 B. Antennae long, with more than five joints. — Nematocera Group 

 (Fig. 144, A). 

 BB. Antennae short, usually 3-jointed; first anal cell narrowed. — Brachycera 

 Group. (Fig. 144) 

 A A. Adults with a frontal lunule; pupa and adult escape from larval skin 

 through a circular opening at anterior end. — Sub-order Cyclorrhapha. 



Fig. 144. — Antennae of common Diplera. A, Xiphuria (Tipulidse). B, 

 Sargus (Stratiomyiidas). C. Stratiomyia (Stratiomyiidas). D, Culex (Culicidas). E. 

 Tabanus (Tabanidae). F, Leptis (Leptidag). G, Chrysops (Tabanidge). H, Anthrax 

 (Bombyliidse). /, Dasyllis (Asilidae). J, Bibio (Bibionidae). K, Gonia (Tach- 

 inidse). L, Pollenia (Muscidae). 



Chief Families of the Nematocerous Orthorrhapha: 



A. A distinct V-shaped suture on back of thorax; legs long and slender. 

 — TipulidcB (Crane Flies) p. 242. 

 AA. No V-shaped suture on thorax. 



B. Veins and margin of wings fringed with scales. — CulicidcE (Mos- 

 quitoes), p. 243. 

 BB. Margin of wings not fringed with scales. 



C. Anal veins wanting; Media vein wanting; tibiae without spurs. 

 — CecidomyiidcB (Gall Gnats), p. 245. 

 CC. Anal veins present and Media vein at least represented by a 

 fold. Costal vein does not extend beyond tip of wing. 



