Host specificity and penetration in the mosquito pathogen Coelomomyces psorophorae

Abstract

A variety of the mosquito pathogen, Coelomomyces psorophorae, collected at Fincastle, Alberta, has been maintained in laboratory-reared larvae of Culiseta inornata and in cultures of the copepod, Cyclops vernalis. Despite earlier speculation, the fungus appears to have a relatively broad host range as revealed by preliminary host-specificity studies. Seven of the 12 mosquito species tested became infected. One species, Aedes vexans, known to be a host for C. psorophorae was not infected, confirming experimentally that host-specific varieties of this species of fungus do exist. Staining with a dilute solution of methylene blue revealed that the fungus encysts in definite patterns on the cuticles of both host animals. Penetration occurs through the cuticle and not through the digestive tract. A correlation between attachment and susceptibility was obvious in these limited trials.