INSECUTOR INSClTli^ MEJNSTRUUS 5 



Territory, July 13, 1919; Dawson, Yukon Territory, July 

 7-11, 1919. 



Aedes lazarensis Felt & Young. 



Culex lazarensis Felt & Young, Science, n. s., xx, 312, 1904. 

 Culex borealis Ludlow, Can. Ent., xliii, 178, 1911. 



Doctor Ludlow gives the indefinite locality "Alaska" for her 

 species. Upon inquiring if she had more definite data, I was 

 informed that the types came from Fort Egbert, Eagle, Alaska, 

 which is in the Yukon Valley, about 100 miles below Dawson. 

 Specimens which are evidently cotypes, although not so marked, 

 from Eagle, Alaska, are in the collection, presented by Doctor 

 Ludlow. They are large, stout specimens with almost normal 

 lacarcnsis markings. 



Males were repeatedly seen swarming at White Horse, after 

 sunset, opposite projecting branches of large spruce trees, 

 10 to 20 feet from the ground. 



This is the most abundant mosquito in the British Columbia 

 mountains and also in the Yukon Valley. It is absent from 

 the Fraser bottom lands, even as high up as Prince George, 

 but occurs a few miles from that place in the valleys of trib- 

 utary creeks. In the Skeena, it is dominant down to tide- 

 water. There appear to be two emergences in this region, first 

 the normal early one from snow-pools, and later in greater 

 abundance from the flood-pools. 



As occurring in the Skeena Valley, lazarensis is of normal 

 coloration. The mesonotum is yellow, with two dorsal dark 

 brown lines and short sublateral ones. Variation is not great. 

 The form with brown sufiFusion on the disk of the mesonotum 

 between the lines occurs rarely. Occasionally the lines are 

 broadened, the two dorsal ones even fused, but this is excep- 

 tional. The ground color is always yellow, never gray. The 

 most striking variation is the obsolescence of the lines, in which 

 case the mesonotum is sufifused with brown centrally. Speci- 

 mens of this form, taken out of doors, were thought at first 

 to be intrudens with the mesonotum marginally lightened ; but 

 I never found any of them in the house. Fortunately a male 



