AQUATIC INSECTS IN NEW YORK STATE 251 



The imagos spend most of their time over the surface of the 

 water, flying from leaf to leaf, or from one mat of floating algae 

 to another. They fly very low, some species so low that 

 it is well nigh impossible to get a collecting net under them 

 without dipping the water. In foraging they fly through the 

 vegetation — not over it, and do not often depart very far from 

 the borders of the water. They flit easily about among the 

 grass stems, where their bands of alternating brilliant blue and 

 black are singularly inconspicuous, and they settle oftenest in a 

 rigidly horizontal position on the perpendicular culms. So far 

 as I have observed, their food is the small Diptera Chironomidae 

 etc., which swarm in such places. They are eaten in numbers by 

 cricket frogs, which lie in ambush amid the floating algae, and 

 catch them when they come to mate and oviposit; by swallows, 

 which can skim close enough to the water to get them, and they 

 are snared in spider's webs, and are eaten by other damsel flies, 

 specially by species of Lestes, as I have observed. 



The eggs are deposited in punctures in the tissues of green 

 plants just beneath the surface of the water. Floating leaves 

 seem to be preferred, but, where these are absent, or too few, 

 the stems of standing aquatics are often found thickly punc- 

 tured, and filled with eggs in all stages of development. They 

 generally fly in pairs and oviposit in oopulo, but they do not, so 

 far as I have observed, descend beneath the surface of the water 

 in ovipositing. 



The nymphs live in tangled, submerged vegetation, and are 

 among the most numerous of the predatory hordes in such situa- 

 tions. They are protectively colored with green and brown, the 

 proportion of each color varying somewhat with that of the 

 surrounding vegetation. When grown, they crawl barely out of 

 the water to transform. In places where there is more sub- 

 merged than exposed vegetation, after a period of transforma- 

 tion, the exposed stems may often be found encircled with a 

 mass of empty skins, clinging one above another where they 

 have been left in a great accumulation, many layers deep. 



It is highly probable that not all the species of the following 

 enumeration will prove entirely distinct; but they have not yet 



