Experiments in which insect cells were cultured with HIV and in which insects were artificially fed with high concentrations of HIV-infected blood have shown that the AIDS virus does not multiply in insects. If transmission of HIV infection by bloodsucking insects is occurring, it would have to be through mechanical transmission during interrupted feeding. In mechanical transmission, the maximum amount of HIV that insects would be able to transfer would be the amount of virus in the blood they had ingested prior to biting an uninfected person. Experience with viruses actually transmitted in this manner has shown that the amount of blood that might be transferred is limited to the amount of blood on the insect's mouthparts. An uninfected person would also have to be bitten within 1 hour of the insect's biting an infected person, and both infected and uninfected persons would have to be in close proximity to each other (a few hundred feet for mosquitoes and biting flies, in the same household for bedbugs), or else the insect will not have an opportunity to transfer to another person if its feeding was interrupted. Suggestions are offered for further studies in this area. 82 references. (Author summary modified)