1924] Biological Notes on Lethocerus americaniis 181 
said there were so many skeletons of fish in this creek that they 
had hesitated to eat them, but after seeing this performance 
they no longer hesitated to eat them, thinking the waterbugs 
were the cause of the death of the fish. The stream was plen- 
tifully stocked with eastern brook trout and they had no trouble 
in getting a good string.” 
Lethocerus adults are strong fliers, and for this reason their 
distribution is quite general. Since these bugs are frequently 
taken at night it is likely they do most of their migrating at 
night. Belostoma flumineum Say, on the other hand is not taken 
at night. Leidy (1847) says both Lethocerus and Belostoma fly 
by night. In several years collecting the writer has never taken 
Belostoma at night although it has been taken on the wing 
during mid-day, far from any body of water. 
Undoubtedly there is but one generation per year, although 
there is no assurance that the adults may not live over the 
second winter and lay eggs the second summer. If this were the 
case the potential damage of a pair of these bugs is indeed great. 
The writer would not be surprised to learn that many of the 
waterbugs produce eggs the second season. He now has spe- 
cimens of Velia watsoni Drake which are over eighteen months 
old. These bugs produced eggs for a period of eight months last 
year and now after a winter rest of a few months, have again 
commenced laying eggs. There seems to be no reason why this 
species should not do the same in nature. It is true that in 
nature their food problem is not simple and enemies have to be 
reckoned with, but on the other hand they no doubt become 
inactive during the winter and perhaps age very little if any at 
this time. Those kept over winter in the laboratory (at room 
temperature) do not hibernate, consequently their greater ac- 
tivity probably shortens their lives. Further observations on 
this form are highly desirable. 
The eggs of Lethocerus americanus Leidy have been searched 
for during the last two seasons but have not been found. The 
eggs of this species were first figured in 1868 (American Entomo- 
logist, Vol. I, pp. 61 and 62) as “The eggs of the Hellgrammite 
Fly.” They were described as “oval, about the size of a radish 
seed, and of a pale color, with some dark markings. They are 
