Hemolymph volume of noninfected and Plasmodium berghei-infected Anopheles stephensi.

The hemolymph volume of Anopheles stephensi adult female mosquitoes was determined by a radioisotope dilution technique. [carboxy-¹⁴C]Inulin was injected into the hemocoels of mosquitoes with a calibrated capillary needle. After sufficient time for thorough mixing, the labeled hemolymph was collected from groups of 50 mosquitoes by a centrifugation technique. Total hemolymph volume was calculated by a conventional formula for radioisotope dilution. The mean hemolymph volume of the newly emerged adult female mosquitoes was 336 nl/mosquito. The ratio of hemolymph volume to body weight was 0.25 μl/mg body wt. By 14 days after emergence, hemolymph volume had dropped to 190 nl/mosquito. Infection of mosquitoes with the rodent malaria parasite, Plasmodium berghei, had no significant effect on hemolymph volume of the mosquito.