THE CANADIAN ENTOMOLOGIST. 349 



CULICID CHARACTERS. 



BY FREDERICK KNAB, WASHINGTON, D. C. 



In the June number of the Canadian Entomologist Miss 

 Mitchell takes Professor Williston to task for including the Corethrids in 

 the family Culicidse. In her article there are so many erroneous state- 

 ments made that, in the interest of truth, they call for correction. Be it 

 clearly understood that I do not accuse Miss Mitchell of falsification. Her 

 errors are in large part due to fragmentary and insufficient knowledge, 

 obtained in part at second hand. 



At the very start it must be stated that the idea of separating the 

 Corethrids from the other Culicidse is by no means a new one. Twice 

 within recent years the family Corethridse has been proposed by 

 independent workers — Dr. Dyar^ in this country and Dr. EyselP in 

 Germany — both of them, by the way, *' nondipterologists." Dr. Eysell 

 has given a very comprehensive presentation of the case, and more than 

 two years ago brought out, not only all the data offered by Miss Mitchell, 

 but a great many others. Indeed, he outstrips Miss Mitchell in classifi- 

 catory enterprise, and also elevates the Anophelines to family rank. This 

 paper by Dr Eysell, which I expect to deal with in another place, contains 

 a great deal that is interesting and suggestive. Unfortunately, not all the 

 data given are correct. Both Dr. Eysell and Miss Mitchell develop their 

 ideas from a few familiar forms. Of the great mass of species, some of 

 which contradict their generalizations, they know nothing. 



In the following I will only deal with the statements of Miss Mitchell, 

 without, however, attempting to take up every detail. The reader should 

 therefore take note that the statements which remain unchallenged are not 

 necessarily correct in every case. 



Miss Mitchell claims that the pupa;: of the Corethrids are not active 

 like those of Culicids. The pupa of Sayomyia lives submerged, that of 

 the Culicine forms floats at the surface ; both become active when 

 alarmed or disturbed, and for activity upon such occasions, the pupa of 

 Sayomyia far surpasses anything in the Culicine group. This difference 

 in the two pupae is largely one of specific gravity. Most Culicine pupae 

 are so buoyant that they cannot go below the surface without a vigorous 



1. H. G. Dyar : Our present knowledg-e of North American Corethrid larvae. 

 Proc. Ent. See. Wash., VII, 13, 1905. 



2. A. Eysell: Sind die " Culiciden " eine Familie ? Sbhandl in Bericht, 

 XLIX, Ver. Naturkunde Cassel, 16-24, 1905. 



October, 1907 



