69 



Family Chironomidse — The Midges 



Small, slender flies, rai-ely over 10 mm. in length, thorax large, the 

 legs slender, antennae of males plumose. 



Head small, more or less spherical, partly concealed from dorsal 

 view by the projecting thorax. Antenna} slender, with five to fourteen 

 segments, the basal segment enlarged and globular, plumose in the males, 

 more or less haired in the females. Eyes reniform or oval, the ocelli 

 al)sent or rudimentary. Proboscis short, not adapted for piercing; palpi 

 with three or four segments. Thorax sub-ovate, or moderately long, more 

 or less projecting in front, without a transverse suture l)ut with a wide, 

 longitudinal impression in front of tlie scutellum; metanotum with a 

 more or less distinct longitudinal groove in the middle; scutellum small 

 and hemispherical. Legs slender and rather long, especially the front 

 pair; the tarsi often very long; empodium and pulvilli present or 

 absent. Wings bare or haired, long and narrow, usually with a strong 

 anal angle; anterior veins strong; auxiliary vein complete though 

 slender; second longitudinal vein weak or absent, the third vein often 

 forked and connected with the first by a crossvein; fourth vein often 

 Avith two branches which may or may not be petiolate basally, the fifth 

 vein usually furcate; second basal cell open or closed apically; costa 

 usually ending at the termination of the third vein, usually well before 

 the tip of the wing. Abdomen narrow and long, especially in the males, 

 shorter and more robust in the females, the hypopygium exposed; ovi- 

 positor short. 



The Certatopogonidffi, formerly included in this family by most 

 authors, have been recognized as a distinct family by JMalloch and Ed- 

 wards, and are so treated here. They may be distinguished l3y the shape 

 of the thorax and absence of the metanotal depression. 



The midges bear little resemblance to mosquitoes when viewed by 

 a careful observer, but to the layman they show no differences and are 

 not differentiated. Many people believe that they are "young" mos- 

 cpiitoes and that they will "grow up", but there is, of course, no justifi- 

 cation for such a belief. In mosquitoes the costa extends entirely around 

 the wing and the wing veins and costa are usually scaled. 



The family is a very large one and comprises close to two thousand 

 described species. Midges are found almost everywhere, but since the 

 larvae are aquatic their distribution is limited to the vicinity of water, 

 although they are frequently found in large numbers at a consideral^le 

 distance from any visible water supply. While they are not strong 



