INSECUTOR INSCITI^ MENSTRUUS 83 



as the * Sandpoint larvae had the upper hairs in threes, the 

 lower in twos, with very considerable variation. Thus the sup- 

 posed differences between this larva and that of hirsuteron 

 Theob. disappear. I compared these larvae with hirsuteron 

 larvae obtained at Hartford, Connecticut, and cannot find any 

 differences. The lateral hair of the sixth abdominal segment is 

 commonly single in both, though occasionally it is double. The 

 skin in both is armed with rather long, sparse spicules. It 

 appears, therefore, that aestivalis cannot be more than a race 

 of hirsuteron, if not a pure synonym, there being no difference 

 in larva, male hypopygium or adult coloration. The only re- 

 maining difference is a slight one of habit, aestivalis being found 

 in the vicinity of lakes, while hirsuteron frequents the flood- 

 pools in river valleys. 



On the other hand, in regard to the nearly related aldrichi 

 D. & K., which frequents river flood-pools in the west, certain 

 differences are apparent in the larvae. Larvae of aldrichi were 

 obtained in a river overflow of wooded bottom-land at Rexford, 

 Montana. The larva has been mentioned by Mr. E. Hearle 

 (Can. Ent., liii, 48, 1921). The lateral hairs of the sixth ab- 

 dominal segment are always single ; the skin is without the 

 little spines, these spicules being very minute, the appearance 

 more granular than spiculate. In addition the air-tube of 

 aldrichi is somewhat shorter and the pecten runs a little further 

 out, reaching just beyond the middle ; the teeth of the lateral 

 comb of the eighth segment have a sharp central thorn, with 

 distinctly less lateral fringes than in aestivalis and hirsuteron. 

 The adult of aldrichi is smaller, and has the mesonotal dark 

 band divided. Rarely this band is united, and in aestivalis 

 there is occasionally a trace of division ; but this variation is 

 not more than is common in mosquitoes. 



Mr. F. W. Edwards has made aldrichi a synonym of the 

 European sticticus Meigen (Bull. Ent. Res., xii, 312, 1921) ; 

 but I think this is an error. From the descriptions ( I am per- 

 sonally unacquainted with the European form) the species 

 might be hirsuteron, and if this species is really common to 



