The larvicidal activity of 104 plant essential oils and their major constituents against third instar larvae of mushroom fly Camptomyia corticalis was examined using a vapor-phase mortality bioassay. Results were compared with those of the conventional insecticides dichlorvos. Over ten plant essential oils exhibited showed more than 90% mortality. At a rate of 0.2 mg/cm3 air, pulegone, and thujone, exhibited 100% morality whereas camphor, 1,8-cineole, α-pinene, thymol and menthol showed 90% mortality at 0.6 mg/cm3 air. Global efforts to reduce the level of highly toxic synthetic insecticides in the agricultural environment justify further studies on the essential oils and their constituents described as potential insecticides for the control of the mushroom fly as fumigants with contact action.