Competence of Aedes albopictus and Culex quinquefasciatus as vector of Dirofilaria immitis after blood meal with different microfilarial density

Aedes albopictus and Culex quinquefasciatus were fed canine blood with diff erent microfilarial density of Dirofilaria immitis ranging from 2500 to 25, 000 mff/ml. Larval development in these two mosquito species did not differ significantly. Although C. quinquefasciatus ingested more microfilariae, t he number of larvae which developed in A. albopictus was invariably greater than in C. quinquefasciatus. Mortality of the engorged A. albopictus was s ignificantly greater than that of C. quinquefasciatus, and higher microfila rial density raised the mortality in both species. The vector efficiency in dex of A. albopictus was greater than C. quinquefasciatus at all microfilar ial densities, but its survival time was much reduced. Thus, dogs with low microfilarial density are implicated as the main source for the transmissio n of D. immitis from dogs to mosquitoes. (C) 2000 Elsevier Science B.V. All rights reserved.