Observations on the sporogony of Plasmodium circumflexum Kikuth and Plasmodium polare Manwell in New Brunswick.

Abstract

The sporogony of Plasmodium circumflexum in Culiseta morsitans is described. Sporozoites were first noted in the salivary glands on the 8th postinfective day; oocysts were still maturing on the 16th postinfective day. Culiseta morsitans was considered to be a good functional vector of Plasmodium circumflexum and the probable natural vector of this parasite in the Tantramar Marshes of New Brunswick. Plasmodium circumflexum did not show sporogonic development in 10 other culicines of three genera obtained in the same area but did complete sporogony in Mansonia perturbans. Plasmodium polare also completed sporogony in Culiseta morsitans and Mansonia perturbans but did not develop in other culicids. A review of the known potential of members of the genus Culiseta as vectors of avian Plasmodium indicates that this genus has previously been underrated and that it shows the greatest potential of all the culicid genera.