Gel diffusion analysis of Anopheles bloodmeals from 12 malarious study villages of Orissa State, India.

In Orissa State, India, the double gel diffusion technique was used to analyze 97,405 bloodmeals of all fed anophelines that were caught during standardized monthly surveys in 12 malarious study villages, from 1982 through 1988. Anopheles culicifacies contributed the highest number of smears from the 19 Anopheles species recovered. It was observed that a pronounced predilection to take mixed bloodmeals attenuates the vector potential of the species concerned. Consequently, prevalences based only upon "pure" (unmixed) primate bloodmeals provide the most accurate way to assess the intensity of feeding contact that actually occurs between a given species and man. By this method, the ranking order is Anopheles fluviatilis, An. culicifacies and An. annularis (N); a sequence which concurs with current knowledge on the vector status of malaria mosquitoes in Orissa.

Gel diffusion determinations on feeding behaviour patterns of anophelines in Orissa State, India.

In 1981 Entomological Field Research Units were established in three districts of Orissa State, India, from which Anopheles bloodmeals were forwarded regularly for analysis to an Entomological Laboratory in Bhubaneswar. At the onset of 1982, the laboratory introduced a modified gel diffusion technique for determining the origin of mosquito bloodmeals and by the end of 1983, 22,300 smears had been processed and analyzed. The technique is relatively very simple, fast and inexpensive. The results are reproducible and the use of double controls (negative and positive) ensure a high degree of reliability.