MICROSPORIDIA PARASITIC IN MOSQUITOES 155 



Stephens and Christopher ('08) mentioned the frequent pres- 

 ence of Nosema (?) in the oesophageal diverticula of the insect 

 without giving further data. 



Thus, on the whole, Microsporidia are rather rarely found as 

 parasitic in mosquitoes, although other Diptera, as Simulium and 

 Corethra, have been found more frequently attacked by them. 



In this connection the writer may add a short review of works 

 on Microsporidia by North American investigators. Gurley ('93, 

 '94) does not seem to have observed any new forms from this 

 continent, although he had studied a number of new forms of 

 Myxosporidia from fresh-water fish inhabiting American waters. 

 Linton ('01) recognized a Microsporidian which appears to be 

 identical with Glugea stephani (Hagenmuller) Woodcock in the 

 intestinal wall of Pseudopleuronectes americanus from Katama 

 Bay. This same parasite was also observed later by Mavor ('15), 

 who mentioned that 50 per cent of the above-mentioned fish in 

 the Woods Hole region were infected by the species, and that 

 Osmerus mordax from the same locality was frequently infected 

 by apparently the same form. None of the authors extended his 

 observations upon the biological features of the organisms. 

 Nosema geophili, an extracellular intestinal parasite of Geo- 

 philus, sp., observed and described by Crawley from Boston, is a 

 very doubtful form, and may possibly not belong to Micro- 

 sporidia. 



Strickland ('13) studied a number of species of Glugea from 

 Simulium larvae in the vicinity of Boston, described Glugea 

 bracteata, G. fibrata, G. multispora, and one ambiguous species, 

 and showed the importance of the study of these parasites on this 

 continent from the standpoint of economic entomology. White 

 ('19) pubhshed an important series of experiments in connection 

 with the practical problems concerning nosema disease of honey- 

 bees due to the infection of Nosema apis. 



We may, therefore, conclude that little is known about the 

 North American Microsporidia. 



