THE EFFECTS OF NATURAL PLASMODIUM-FALCIPARUM INFECTION ON THE FECUNDITY AND MORTALITY OF ANOPHELES-GAMBIAE SL IN NORTH-EAST TANZANIA

Rodent and avian malaria parasites have been reported to have an adver se affect upon the reproductive fitness of mosquitoes. In order to det ermine whether fecundity reduction occurs in Anopheles gambiae s. I. i nfected with human malaria a study of wild-caught mosquitoes was under taken in the Muheza district of north east Tanzania. Fully engorged, i ndoor resting females were collected daily for 4 months and maintained for 5 days. A sporozoite rate of 11.5 % was detected for the whole co llection and of those females alive on day 6 an additional 17.5 % were infected with oocysts alone. Oocyst, but not sporozoite, infection re sulted in a 17.5 % reduction in egg production. Fecundity reduction wa s not caused by a reduction in bloodmeal size in infected females and no size difference was detected between oocyst-infected and uninfected females although sporozoite-positive females were significantly large r. Comparisons in parity between uninfected and infected groups indica te that infection does not affect survival beyond the first gonotrophi c cycle as no changes in survivorship occurred as a result of sporozoi te infection.