Volatile low molecular weight insecticides possess fumigant-like activity, and have potential applications in integrated pest management. Here, we report on investigations into the toxicity, resistance potential, and possible modes of action for volatile insecticides that are representatives from two structural groups (heterobicyclics and alkyl-esters). In these studies, we used insecticide susceptible and resistant Drosophila. In particular, the resistant strains possesed metabolic resistance (Hikone-R strain), as well as neurological insensitivity (para and Rdl strains). By this approach, we have been able to (1) rank the relative activity of ~30 candidate insecticidal compounds, (2)identify potential resistance/cross-resistance characteristics, and (3) gain insights into modes of action of the ~30 compounds.