April, I9I7 Bulletin of the Brooklyn Entomological Society 21 



CONCERNING GERRIS REMIGIS SAY. 



By Chris. E. Oslen, Maspeth, L. I. 



April 4 at Alpine, N. J., I collected seven specimens of this 

 species for breeding. They fed readily on spiders of the family 

 Theridiidse, the only food I could get at the time. Later I tried 

 a species of Drassidse, but it was too powerful. The Gerris 

 abandoned the attack and allowed the prey to escape. First 

 copulation was observed April ii among the four survivors, 

 three having drowned.. Four had gone to the bottom of the jar 

 containing them. I laid one on a blotter to be pinned. A few 

 hours later I found it moving its legs feebly. When it recovered 

 I put it back in the aquarium. After a square meal it seemed 

 as vigorous as ever. 



Copulation was a sort of continuous process. April 19 I dis- 

 covered five eggs on the side of the aquarium ; next day two 

 more deposited on a straw. The eggs were placed in a separate 

 vessels for observation. The first young emerged in seventeen 

 days, imperfectly developed, unable to expand, and it died next 

 day by drowning. The next hatched May 8, and next day had 

 its first meal, a Drosophila ampelophila, of which I had bred 

 numbers for feeding. It was very amusing to watch the Gerris 

 attack the prey much larger than itself. It would jump around 

 from side to side, apparently looking for the best place for attack. 

 It finally landed quickly as eye could follow, jumped away with 

 equal rapidity, repeating a number of times, inserting its beak 

 each time, the fly becoming weaker and finally offering no 

 resistance. 



May 15 first cast skin found floating. May 22 the second; 

 and food hereafter was a small microlepidopteron. May 31 

 third exuvia; June 9 fourth; June 24 fifth and a perfect imago, 

 wingless of wingless parents. 



