Entomologists suggest that malaria-carrying mosquitoes may not be manipulated by the parasites that they carry, infact, it may just be an immune response. "Normally, after a female mosquito ingests a blood meal, she matures her eggs and does not take another one until the meal is digested," said Lauren J. Cator, postdoctoral fellow in entomology and a member of the Center for Infectious Disease Dynamics, Penn State.
"If infected, however, mosquitos will wait to eat until the parasites developing within the gut mature and migrate to the salivary glands. "It was thought that fasting until malaria could be transmitted was beneficial to the malaria parasite because if the female mosquito was not feeding, she was not being swatted. The return of hunger seemed to correlate with the migration of parasites to the salivary glands. The hungrier the mosquitos are, the more they feed and the more chances to find new hosts.
Cator and colleagues who included Justin George, postdoctoral fellow; Simon Blanford, research associate; Courtney C. Murdock, postdoctoral fellow; Thomas C. Baker, professor of entomology; Andrew F. Read, professor of biology and entomology and alumni professor in biological sciences; and Matthew B. Thomas, professor of entomology, used a mouse model and showed that indeed female mosquitos behaved in this way.