Feasibility experiments to evaluate the gas phase insecticidal activity of several silanes has demonstrated that (Me0)4Si is active at a single exposure concentration of about 500 ppm (v/v), (MeO)3SiR is active at somewhat less than 500 ppm, and Ne3Sir is lethal at 50 ppm. The relationship between insecticidal activity and mammalian inhalation toxicity for the alkoxysilanes is about the same as known for commercially useful fumigants. The alkoxysilanes may have an advantage in that (1) the half-life can be easily controlled and (2) the residual hydrolysis products can be limited to amorphous silica and methanol.