MOSQUITOS, AEDES-CANADENSIS AND AEDES-VEXANS AS POTENTIAL VECTORS OF DIROFILARIA-IMMITIS IN MARYLAND

Females of Aedes canadensis (Theobald) and A. vexans Meigen were reared from field-collected larvae and pupae and were given opportunities to feed on a dog infected with Dirofilaria immitis Leidy, the cause of dog heartworm disease. Mosquitoes which took blood were dissected and examined to determine the course of development of the parasite. Both species fed readily on the dog. At 18.degree. C maturation of larvae to the 3rd infective stage and movement to the head and mouthparts occurred in a minimum of 27 days. At 26.degree. C development was completed in a minimum of 14 days in A. vexans. Infective stage filariae were found in the head and mouthparts of 75% of 156 A. canadensis; the maximum number in 1 female was 36; the average number was 4.7. Infecive stages were found in the head and mouthparts of 68% of 101 A. vexans with the maximum 48 and average 10.8.