The mosquito study, which was reported by The Atlanta Constitution today, is designed to explore the hypothesis that insects might somehow be involved in transmitting the AIDS virus, according to Dr. Jai Nayar, the insect specialist who is participating in the study.

Dr. Nayar, of the Medical Entomology Laboratory in Vero Beach, Fla., said that mosquitoes from colonies in Florida had been fed in the laboratory on blood infected with the AIDS virus and tests had then been performed to see if the virus remained in the mosquito and could be passed on by the mosquitoes to uninfected blood.

Preliminary results indicate, he said, that ''the virus can stay in a mosquito for two or three days once the mosquito feeds on it.'' Whether it can stay even longer is still under study, he said.

But Dr. Nayar said there was ''very little indication so far'' that the mosquitoes would pass on the virus to a sample of uninfected blood while feeding on that sample, although such experiments are not complete.

Dr. Gallo was more emphatic, saying the study had so far found no evidence that mosquitoes passed the virus on to uninfected blood from which they eat.