MAY FLIES AND MIDGES OF NEW YORK 79 



proving that these fish live almost exclusively upon " blood- 

 worms," at certain seasons at least. Garman (1888) says: 

 " Probably no other one genus of insect constitutes as important 

 an item in the food of as large a number of fishes." While Forbes 

 (1877) in giving a list of the organisms which form food of 

 fishes records Chironoinidae as occurring in the stomachs 

 of many species. 



Enemies 



Besides the fish which devour vast numbers of Chiron o mid 

 larvae, the nymphs of dragonflies, caddis worms, Perla, Sialis, 

 beetle and other predaceous larvae constantly prey upon them; 

 while the adults are eaten by dragonflies, by the net-winged 

 midges (Blepharoceridae) and other predaceous insects. 

 In a swarm of these midges very often one also sees a number 

 of danceflies (E m p i d s) constantly seeking victims. 



Methods of capturing, rearing and mounting 



Sweeping the low brush, rank grass, and herbage along the 

 banks of ponds and streams is the usual way of capturing these 

 flies, and often in a favorable location hundreds may be caught 

 in a few hours; but the most satisfactory manner of catching 

 is by means of a cyanide traplantern, such as is described by 

 Professor Needham (1901, p.398). By means of it several 

 thousand specimens may be taken in a single night. The most 

 favorable time for setting the lantern is a sultry, cloudy night, 

 during the summer or spring; and the most favorable location 

 is near the bank of a pond or creek. 



The larvae and pupae and sometimes the eggs also may be 

 scooped from the bottom of the pond by means of a small coffee- 

 strainer net; or swept by means of a brush into a cloth sagnet 

 from the surface of the rocks at the bottom of the shallow creek 

 as described by Professor Needham (1899, p.5). From thence 

 they are transferred to jelly tumblers, or for those forms which 

 require rapidly flowing water to a jar from which the water 

 is drawn as rapidly as it enters by means of a continuous siphon 

 as described by Professor Corn-stock in " Insect Life," p.330. If 

 the larva is nearly full fed, but a short time will be required 

 for it to transform. If the specimens are still quite small, some 



