I08 MEGARHININiE [CH. 



Tribe 2. MEGARHiNiNiE, 



Proboscis with the apical half much thinner than the basal, 

 and bent downwards at an angle with it, Scutellum evenly 

 rounded. Wings long and narrow ; fork cells both very short, 

 but with the first much shorter than the second. Large species 

 completely clothed with flat, more or less metallic, scales, usually 

 blue or green. Larvae predaceous ; adults not bloodsuckers. 



The Megarhininae are popularly known as Elephant mos- 

 quitoes owing to their enormous size. None of the species 

 have been shewn to be directly concerned in the spread of 

 disease, but the predaceous larvae of some species play an 

 important role in keeping down the number of other species 

 of mosquitoes, T. immisericors (Walker), the common Elephant 

 mosquito of India and Burmah, for example, in the larval stage 

 is generally found living on the larvae of Stegomyia. The two 

 chief genera are Megarhinus and Toxorhynchites , the former 

 of new world and the latter of old world distribution. 



Tribe 3. Culicin^e. 



Thorax more or less rounded ; metanotum without 

 bristles ; scutellum more or less distinctly trilobed. Larvae 

 with air tube and median ventral brush on anal segment (after 

 the first stage). 



This sub- family includes over 600 species and, next to the 

 Anophelinae, is the most important from the point of view of 

 the transmission of disease. Theobald in his monograph 

 recognizes nearly 100 genera, arranged as follows : 



In addition certain peculiar forms have been given the 

 rank of a sub-family by Theobald, In other respects having the 

 characters of Culicinae, but differing in having a seventh vein 

 on the wing with scales, is Heptaphlebomyinae. Also resembling 

 Culicinae, but having a very long second segment of the antenna, 

 is Deinoceratinae. 



