Insect Life on the Western Arctic Coast of America 9k 
In the fresh waters of northern Alaska insects and larvae are abundant, 
even in winter, as compared with those on land. They were observed in frozen 
ponds and lakes and in a warm creek, a tributary to Sadlerochit river, back of 
Camden bay. In a pond only 4 feet deep, on which the ice was 10 inches thick 
on October 9, many copepods, Limnocalanus johanseni Marsh, ostracods, and 
other minute animals, and a number of midge larvae were found. Ponds such 
as this would, of course, freeze to the bottom later in the winter. From a neigh- 
bouring stream a perlid nymph was obtained from beneath the ice. Examina- 
tions of the lakes and ponds in spring and early summer led to the conclusion 
that the following forms hibernate in or near fresh water: — 
Aquatic diptera — larvae (especially tipulids and muscids). 
Dytiscid — beetles. 
Trichoptera — larvae and perlid larvae. 
Mosquitoes — females, a lew (Aedes sp.). 
Various midge larvae. 
Hydrachnid mites. 
The warm creek back of Camden bay has its source in three springs, at 
the foot of a mountain about 25 miles from the coast, and flows for a few miles 
nearly parallel to Sadlerochit river before joining it. Its rather luxuriant 
vegetation consists of grasses, sedges, and green algae^ on the sandy and muddy 
bottom, and of an algse-crust and mosses, as a carpet, on the submerged stones. 
Parts of stones just above water carried a white crust of siliceous or calcareous 
algse, and stones above high-watermark, had a luxurious growth of lichens. The 
water at the source was steaming and had a temperature here of about 60 
degrees F., but became colder as the stream was descended. The steam and 
the open character of the stream contrasted strangely with the surrounding 
snow-clad, silent tundra (November, 1913). 
In this warm water (above 35 degrees F.), a number of grayling, Thymallus 
signifer Rich, and trout were seen feeding on the rich invertebrate life, which 
consisted of larvae of midges, perlids, and phryganeoids. A species of phryganeoid 
larvae typical of streaming water, was living inside gravel cocoons attached to 
the underside of the stones. There were also many amphipods (Ganimarus 
Umnceus) and small clams (Pisidium) and hundreds of snails (Lymnea caperata) 
were clinging to the mosses and algae. All these, with many microscopic forms, 
made an unusually rich animal collection. 
Apart from the insects found in the warm springs and creeks which keep 
open all winter, there appears to be no difference between insect life in the up- 
land and that at the coast, except that some species {Bombus, Vespa, and ants) 
take advantage of cliff-crevices or old bark on the taller willow trees, to build 
their nests or to hibernate as larvae. Observations up the Sadlerochit river 
were, however, made in November, at which time the cold had killed most of 
the insects, and much snow covered the ground. 
In the reports of the various specialists, information is given concerning 
the seasonal occurrence of the various insects in their immature stages; and it 
will be seen that the life history of insects is much the same in the Canadian 
Arctic as in more southern latitudes. The following tentative table summarizes 
very roughly the facts concerning the hibernating of arctic insects, not 
including parasites: — 
» See this series of reports, Vol. IV, Part A. Freshwater Algae and Freshwater Dieatoms. 
