REPORT OF THE STATE ENTOMOLOGIST 1907 I/Q 



its nymphal skin floating on the surface, and, alighting on the first 

 support that offers, sheds its skin again, and the subimago stage is 

 ended. Then it flies for a Httle while, the males dancing up and 

 down in a little swarm, as in other "species, and the females coming 

 out to meet them. It probably lives in all but a few hours of adult 

 life. I have frequently watched the swarming until it was entirely 

 obscured by darkness. Specimens of this species emerging from 

 the hatchery troughs at Saranac Inn deposited their eggs in little 

 clusters of 200 to 300 upon the window panes. 



The nymphs of this little May fly abound wherever there are 

 beds of waterweeds. They rest upon the silt covered bottom or 

 cling to the stems of the plants. They cling closely and, being 

 entirely covered with silt, are quite unobservable except when dis- 

 lodged. Because they cling so closely they are not easily collected 

 nor easily separated from the trash. That they exist in inconceiv- 

 able vast numbers is demonstrated most readily by the use of a 

 trap lantern. Our lanterns at the pier were sometimes almost 

 choked with them and thousands besides were found upon the 

 supporting post and upon the lantern itself outside ; and this con- 

 dition of things has prevailed in every locality of the United States 

 in which I have run a trap lantern over still water. I have no 

 doubt that these very minute nymphs, too small for proper food 

 for the larger fishes, are of very great importance to young fishes 

 and to the smaller species. They are scarcely mentioned hitherto, 

 however, in the literature of the fish food. 



Only two other insects were found ; a half grown nymph of a 

 dragon fly of the genus Aeschna, that was eaten by fish number 

 3, and a water skater, by fish number 5. 



Of the crustaceans eaten, all were Entomostraca. But three 

 were Ostracods, and these were eaten singly. Copepods were eaten 

 abundantly by the smaller fishes of lot three, sparingly by those of 

 larger size. I was unable to determine any of them. Apparently 

 there were but few species. The great importance of Copepods as 

 food for young fishes has been abundantly demonstrated hitherto 

 through the labors of others. Nevertheless, the conditions that 

 make for their abundance are scarcely at all understood. Cladocera 

 were eaten as a rule very sparingly, only one fish (number 12) 

 having eaten any great number; it had eaten almost exclusively a 

 species of Bosmina. The others so sparingly eaten belonged to the 

 genera Alona and Chydorus. 



