Insect Life on the Western Arctic Coast of America 27k 



sp.) emerging from perlid nymphs were noticed. The nymphs were crawling 

 up on the stones in the creek. Attached to these stones by their rear suctorial 

 disk-wart were simuhid (black-fly) larvse up to 1 cm. long. About a dozen 

 were sitting together on each stone and when the stones were lifted, the larvse 

 released their hold and tried to slip off. When placed in a tumbler, they could 

 easily dimb up the glass by the aid of their thoracic (central) "wart-leg" and the 

 suctorial disk at their hind end, somewhat after the manner of a spanner worm. 

 Or they would spin threads from the water-surface to the inside of the glass 

 and ascend on them, but they are not able to float without these threads. When 

 at rest, these larvse attached themselves to the glass or to the threads by their 

 hind disk and kept the body straight out or at some angle. Only then are 

 their famous plumose gills to be seen on the expanded neck. These are 

 folded up and stretched out, one at a time, continuously, with varyipg quick- 

 ness; there is about one second between two "strokes," simultaneously with 

 the maxillse, but the latter move both together. 



The powerful and varied means of locomotion possessed by these simuliids 

 is due to their living in running water, the scarcity of which around Bernard 

 harbour at this period probably explains the scarcity of the fly. Farther east, 

 the species is very common. Efforts to rear the larvse were unsuccessful. 



June 21-SO, 1915 



Flying insects now are often met with {Bombus neoboreus, etc., all queens, 

 various flies, etc.) but the majority of insects are still upon the ground. 



The ponds and lakes around the harbour, the lakes being only partly free 

 of ice, were examined. In the ponds were the common mosquito larvse {Aedes 

 nearcticus) and an occasional fly larva {Rhamphomyia sp.), freshwater snails 

 {Aplexa hypnorum) attached to grass leaves or as empty shells upon the mud 

 bottom, dytiscid beetles, midge larvse tubes of caddis-flies, etc., and two kinds 

 of water mites. One of these mites (Thyas stolli) is 1-1§ mm. long, has black 

 eyes, and a round and flattened abdomen of a bright rose colour. It is always 

 seen crawling over the mud bottom. The other mite (Curvipes reighardi) is less 

 than 1 mm. long and has the ball-shaped abdomen tile-red with the legs and 

 cephalothorax still darker. It is not so often seen crawling, but generally paddles 

 with all its long-haired legs, rising or sinking in the water at will. 



The large lakes contain various trichopterous larvse in their tubes ; they will 

 attach themselves even to a baited hook. The usual dytiscid beetles and 

 various midge larvse (Chironomus sp., etc.), and the larger dipterous larvse are 

 present. CrawUng on the bottom in the marginal water are perlid larvse 

 (nymphs), evidently near their final transformation, for over the snow covering 

 the lake ice one mild day (June 25) a number of imagines {Capnia nearctica), 

 probably of the same species, were seen crawling with wings already, but not 

 fully developed. They may have come up through cracks in the ice, or from 

 the ice-free marginal water. The direction in which they crawled indicated 

 an instinctive knowledge of the location of the shore, even if they are far out on 

 the lake. They perhaps make for the shore to copulate, but their hf e as imagines is 

 probably very short. Three months later in the same locality, similar instances, 

 but on a larger scale, were seen, only it was then trichopterous imagines. On 

 these lakes the usual collembola (Podura aquatica, etc.) assembled in large colon- 

 ies, the full-grown blue ones carrying their small, brown, young ones on their 

 backs in grebe style. Minute, jumping-flying flies were also common. A larger 

 fly with similar locomotion had half a dozen minute, flat, round mites on the 

 central side of the first abdominal rings. 



July 1-10, 1916 



Many flowers are out, resulting in a great number of insects. The flying 

 varieties include flies, crane-flies, midges, and mosquitoes. The crane-flies are 

 typical of dry tundra places and are frequent on ponds. Of hymenoptera, various 



