On the Growth of Dirofilaria Immitis in the Mosquito

Abstract

Summary Generally similar growth curves of Dirofilaria immitis larvae were noted in the following experimental mosquito hosts: Culex pipiens, C. quinquefasciatus, and their F2 hybrids; Aedes aegypti and A. albopictus; Anopheles quadrimaculatus and A. freeborni. The host constitution apparently had an effect upon the size attained by the filaria larvae, and the larval length/width ratio varied considerably between genera and also, in Culex and Aedes, between species, but to a lesser extent in Anopheles. Thus phylogenetic affinities between mosquito species do not necessarily imply similar growth of the dog filaria within them. Third stage larvae undergo considerable change in length especially in favorable mosquito hosts. Nevertheless, at 20 days after the mosquito's infective meal the third stage filaria larvae still are to be found both as long and short individuals. Whether this is linked with sex differentiation is not known.