THE CANADIAN ENTOMOLOGIST. 179 



A RECENTLY DISCOVERED GENUS AND SPECIES OF 

 AQUATIC HYMENOPTERA. 



BY J. CHESTER BRADLEY, PHILADELPHIA, PA. 



In the Annales Soc. Ent. de France, LXIX., p. 171, P. Marchal 

 publishes an article entitled "Surun nouvel Hyme'noptere aquatique, le 

 Limnodytes gerriphagus, n. gen., n. sp." 



Mr. Marchal is to be complimented on his discovery and observa- 

 tion of the habits of this very interesting insect, but it is deeply to be 

 regretted that the generic name which he has chosen is preoccupied, 

 hence it becomes necessary to change it, and desirable to do so at once, 

 before it becomes widely known. The name Limnodytes was employed 

 by Dumeril and Bibron in their " Erpe'tologie generate," Vol. VIII., 

 1841, p. 510, for a genus of salamanders, hence I propose in its place the 

 term Tiphodytes, nov. name. 



In this connection I may apropos make a few remarks, gathered from 

 MarchaPs paper, concerning the habits and relations of this insect. 



Metchnikoff, and after him Ganin, mentioned finding an unknown 

 species of Teleas as a parasite on the eggs of Gerris (Hemiptera- 

 Heteroptera). Marchal found the present species during the month of 

 May, in the pond of Trivaux, Meudon, near Paris, also parasitizing the 

 eggs of Gerris, but he considers it distinct, although closely related to the 

 one found by Metchnikoff and Ganin. On the 12th of May he collected 

 eggs which were animated with the larvae of the parasite. These eggs 

 were always arranged along the lower surface of Potamogeton leaves. 

 The larvae differed from those figured by Ganin in the arrangement of the 

 hair and brevity of the caudal cornus. In June, four female and two male 

 adults hatched, and these used their wings for swimming in any direction 

 through the water, with a leisurely movement. When they came to the 

 surface they had to make an effort to pass through it into the air, where 

 they readily took flight. Likewise, in entering the water the insect bent 

 its head forward and made a visible effort to conquer the resistance 

 offered by the surface film, unless it entered on the edge of a projecting 

 leaf or twig. 



My excuse for entering at length here into an abstract and discussion 

 of MarchaPs article is because aquatic examples of the Hymenoptera are 

 very few, and the fact that winged adults of such an order should enter and 

 swim in the water must interest many entomologists who will never see the 

 original article. 



