DIPTERA: CULICID.E. 413 



:, Latr., OR GNAT FAMILY. This Family 

 comprises diptera which have the body and legs much 

 elongated and very delicate, antennae densely pilose, and 

 which have a long piercing sucker consisting of five bris- 

 tles. Such are the Gnats and Mosquitoes which abound 

 in all parts of the world, and which are represented by a 

 large number of species. The female lays her eggs on 

 the surface of the water, and the larvae may be seen in 

 all stagnant pools throughout the warm and hot months, 

 for there are several generations in a season. The larvae 

 rest with the head downwards, and the hind extremity, 

 which contains the respiratory openings, is at the surface 

 of the water. They are very lively, and swim or wriggle 

 with great agility, dive from time to time, but soon come 

 again to the surface in order to breathe. At length they 

 cast their skins and enter the pupa state, in which they 

 still live at the surface of the water, and move by means 

 of the tail ; but they now take a different position, and 

 breathe through two tubes placed on the thorax. After 

 being in the pupa state a few days, the skin splits on 

 the back between the breathing-tubes, the winged insect 

 appears, and, after resting awhile on the empty skin as 

 it floats upon the surface of the water, spreads its wings, 

 and, humming its peculiar note, flies away in search of a 

 victim whom it may pierce for blood, which is its choicest 

 food. These insects discharge a poisonous fluid into the 

 wounds which they inflict, and this is the cause of the 

 irritation and swelling which results from their attacks. 



TIPULAR^LE, Latr., OR CRANE-FLY FAMILY. This 

 Family embraces diptera which have the body slender, 

 legs very long, and long antennae and palpi. The Genus 

 Cecidomyia has the antennae verticillate. 



The Hessian Fly, C. destructor, Say, is one tenth of an 

 inch long, and expands about one fourth of an inch ; 

 head, antennae, and thorax black ; wings blackish, except 



