1921 ENTOMOLOGICAL SOCIETY. 69 



segments have broad, basal stripes and the hind, tibiae have also broad, stripes. The 

 poison of this species is more virulent than that of any other Canadian mosquito, 

 but fortunately the species is a rare one in the Lower Fraser Valley. It breeds 

 in permanent swamps where there is much vegetation. The larva? and pupae do 

 not come to the surface to breath, but remain attached to the submerged portions 

 of certain aquatic plants. 



Artificial Receptacles and Small Collections of Waters. 



Culiseta incidens Thompson. This is the common rain-water barrel mosquito 

 of British Columbia, and is one of the most abundant mosquitoes of the Lower 

 Fraser Valley. Fortunately the blood-lust is so poorly developed that the species is 

 practically non-predaceous on man. The very large size, dark appearance, and the 

 black spots on the wings render the species an easy one to recognize. The abdomen 

 is truncate at the tip and has broad white basal bands. The thorax is ornamented 

 with indistinct markings and the legs have very indistinct bands at the apiees'of the 

 tarsal segments. The larvae, although preferring rain-water barrels to other breed- 

 ing places, are to be found in a great variety of habitats, even having been taken in 

 brackish coastal pools in company with Aecles curriei. 



Culex pipiens Linnaeus. This mosquito has probably only recently been 

 introduced into British Columbia, as it was found only in Vancouver and was very 

 scarce there. It was probably brought in by shipping, as it is known to have been 

 very widely spread in this way. The species is one without very outstanding char- 

 acters. The abdomen has crisp white basal bands, the legs are dark and unhanded 

 and the thorax is a du'sty reddish-hrown. Although rain-water barrels are the 

 favorite larval habitats, the larvae are to be found in almost any collections of water 

 round houses. Culex pipiens is essentially a domesticated species whereas Culiseta 

 incidens is in the transition stage and is only semi-domesticated. 



Miscellaneous. 



Culiseta impatiens Walker. This very large brown mosquito is fairly com- 

 mon in the Lower Fraser Valley, but is of little economic importance. The legs 

 and prosboscis are brown and unhanded and the thorax is clothed with brown 

 scales. The abdomen has broad basal segmental bands. 



Culiseta inornatus Williston. This mosquito is very hard to distinguish from 

 the last. The color is .somewhat paler and the cross-veins on the wings are scaled, 

 unlike C. impatiens, in which they are bare. This species is comparatively rare. 



CuUseta alaslccensis Ludlow. This species is larger and darker than the above 

 two, and is easily recognized by the indistinct spots on the wings and the distinct 

 white basal bands on the tarsal segments. It is a very rare mosquito in the Lower 

 Fraser Valley. 



Besides the above, two other species were found which have not yet been identi- 

 fied; one of these, a rare species from the Fraser Canyon, appears to be new to 

 science. 



Eucorethra underivoodii and Sayom.yia trivittata, two interesting insects very 

 closely allied to the true mosquito, were also found to be fairly abundant in the 

 district. 



In dealing with the mosquito problem of the Lower Fraser Valley only two 

 species need to be given serious consideration. The peculiarities of topography and 

 flooding, at times, provide these two members of the mosquito fauna with satisfac- 

 tory conditions for developing in enormous numbers. The reclamation of the low 

 lands bordering the river, by dyking and pumping, has proved to be the most effec- 



