Ethanol, acetic acid and ethyl acetate are generated during the degeneration of palm tissues infested by the red palm weevil, Rhynchophorus ferrugineus Oliv. This in vitro study determined the in uences of concentrations of 0.05-2% v/v of these substances in distilled water on the behaviour, survival and infectivity of the entomopathogenicnematode Heterorhabditisindica, a candidate species for control of R. ferrugineus. The observed responses of the nematode included normal movement, reversible partial paralysis and death. The estimated LC 50 were 1.48, 0.25 and 0.14% for ethanol, acetic acid and ethyl acetate, respectively, but only 0.18% for the equal mixture of all three. Nematodes that survived treatment at the LC 50 of each substance showed infectivity and penetration activity comparable to those of control nematodes. We conclude that it will be dif cult to control R. ferrugineus using H. indica in the presence of these substances in palm trunks.

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