The acaricidal activity of 54 commercially available plant essential oils against Tyrophogus putrescentiae adults was compared with those of benzyl benzoate and N,N-diethyl-m-toluamide (deet). Responses varied with test oils. In a test with an impregnated fabric disc bioassay at $12.7mu extrm{g} extrm{cm}^2$, over 80% mortality was observed with bay, citronella java, clove bud, clove leaf, lemongrass, nutmeg, oregano, pimento berry, thyme red, and thyme white oils, These oils were more toxic to T. putrescentiae adults than benzyl benzoate and feet. At $6.4mu extrm{g} extrm{cm}^2$, lemongrass and thyme white oils exhibited 76 and 84% mortality, respectively, whereas the acaricidal activity of the other essential oils was significantly decreased. In a fumigation test with adult mites, lemongrass and pimento berry oils were much more effective in closed containers than in open ones, indicating that the effects of these oils were largely due to action in the vapor phase. Plant essential oils described merit further study as potential r. putrescentiae control agents.