The effects of infection with Plasmodium yoelii nigeriensis on the reproductive fitness of the mosquito Anopheles gambiae

Malaria parasites are known to affect the fecundity of several species of m osquitoes but the effect of the parasite on the next generation of the vect or had not been investigated. Here we report the results of a laboratory st udy designed to determine the effects of a rodent malaria parasite, Plasmod ium yoelii nigeriensis, on the reproductive fitness of females feeding on a n infected blood meal. Female Anopheles gambiae from the same generation an d of the same age and size were fed on a gametocytaemic or non-infected mou se, and the reproductive fitness of individual females monitored. Fecundity (total number of eggs produced) and fertility (number of larvae hatched) w ere significantly reduced by 41.2% and 61.8%, respectively. In the resultin g offspring, there was no significant difference in the survivorship of the larvae. The sex ratio, wing length and symmetry, and the blood meal size o f the F-1 adults were also unaffected, suggesting that parasite-induced red uction in fitness is not carried over to the succeeding generation.