A Study on the Ability of Medetera sp.(Diptera : Dolichopodiae)to Prey upon the Bark and Wood Boring Coleoptera

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Many species of Medetera have been reported as predators of the bark and wood boring Coleoptera since 1870 (Parris), but the author doubts wherther the species of Medetera sp.-A, found in Chiba Prefecture, is a predator of living larvae o the bark and wood boring Coleoptera. To resolve this question, the first experiment was done so as to know wherther a solitary larva of Medetera sp.-A attacks a living larva of the bark weevil, Pissodes obscurus, in the larval gallery, and the second was done so as to know whether the fly-larvae become aggressive when aggregated. Results were negative.Then the third experiment was done to find out the food on which the fly-larva feeds and grows, and it was found that the fly-larva grew by feeding on dead weevil-larvae.From these experiments, it was considered that Medetera sp.-A was not a predator but a zoonecrophaga.