PLASMODIUM-YOELII-NIGERIENSIS - THE EFFECT OF HIGH AND LOW-INTENSITY OF INFECTION UPON THE EGG-PRODUCTION AND BLOODMEAL SIZE OF ANOPHELES-STEPHENSI DURING 3 GONOTROPHIC CYCLES

Anopheles stephensi mosquitoes showed a reduction in fecundity over 3 successive gonotrophic cycles, after becoming infected with Plasmodium yoelii nigeriensis. This effect could be observed at high oocyst burd ens (> 75) or at low oocyst burdens (mean of 4.36). Mean bloodmeal siz e of the infected mosquitoes was significantly reduced only when feedi ng upon a mouse with a high gametocytaemia and the conversion of the b loodmeal into eggs by the infected mosquitoes was disrupted. Patterns of infected mosquito mortality, over the 3 gonotrophic cycles, varied with severity of infection. Although in 1 case increased mortality and decreased bloodmeal size may have affected fecundity, this could not have accounted for all of the observed fecundity reduction. We propose that other, unknown parasite related factors, are involved.