248 Annals Entomological Society of America  [Vol. XIV, 
those close to their own habitats. Referring to the hibernation 
of Gerris orba Stal, a congener of Gerris remigis, Essenberg 
(1915a, p. 397) states that: 
The water-striders pass the winter as adults, hibernating under 
logs, rocks, rubbish, and in other sheltered places. 
It is evident that these two species pass the winter in some- 
what similar situations. While Hungerford (1919, p. 117) 
has little to say regarding the hibernation of Gerris remigis, the 
records that he does give are correct. He remarks that: 
Our large G. remigis winters as an adult hidden under some brush, 
logs or other shelter about the water. 
His records are from Kansas and it is interesting to notice 
that he points out the fact that this species hibernates in the 
vicinity of its own habitat. It should be stated that Gerris 
remigis is mainly an apterous species (Fig. 1) and it is to be 
expected that few even of the alate forms (Fig. 11) will be 
found hibernating at any great distance from their aquatic 
habitats (Figs. 4, 5, 6; 7, 8, 9). In a paper by me (19192, 
p. 484), on certain habitat responses of Gerris remigis, there is 
a brief statement of some extended observations on the hiberna- 
tion of this species on and near the margin of a large pool, 
at the headwaters of a small, rapid stream, in the vicinity of 
Syracuse, New York, which is quoted here: 
They [Gerris remigis] undoubtedly hibernate, in large numbers, 
along the shores of this pool. In fact, I have found a few of them hiber- 
nating in interstices where the shore slightly overhangs the water, and 
also among dead leaves and other vegetation at points from a few 
inches to three yards away from the pool. 
On several occasions, a few alate individuals (Fig. 11) have 
been found hibernating within three yards of the water (Fig. 5). 
In all of these situations, where water-striders were found, 
the insects kept in close contact with their immediate sur- 
roundings and with each other. In some of these places, 
they have been taken in large numbers (Figs. 6, 7, 8, 9). They 
have been found in groups, frequently as many as fifty individ- 
uals in a cluster. Sometimes the aggregations were so large 
that one hundred and fifty to two hundred and fifty gerrids 
have been counted. Often in these winter quarters (Figs. 
5, 6, 7, 8, 9, 10) they lie in close contact with each other, their 
bodies being closely applied. Such responses were, very 
probably, due to their thigmotactic propensities. 
