Stored-product insect pests and their natural enemies were investigated in Chichijima Island, Ogasawara (Bonin). Sixteen species belonging to eight orders, Thysanura, Dermaptera, Blattaria, Hemiptera, Coleoptera, Diptera, Lepidoptera and Hymenoptera, were collected in and around the stored condition. Two beetles of stored-product insect pests, Alphitobius laevigatus (Fabricius) and Tribolium castaneum (Herbst) were abundant in a henhouse. Carcinops pumilio (Erichson), a natural enemy of stored-product insect pests, was abundant in the same henhouse. Several individuals of two heteropteran bugs, Clerada apicicornis Signoret and Fulvius anthocoroides (Reuter), were also confirmed in the henhouse. The larvae of these two bugs successfully emerged after reared with the larvae of Tribolium confusum Jaquelin du Val as prey. Opogona sacchari (Bojer), Euxestus parki Wollaston and Pheidole megacephala (Fabricius), found in and around the stored condition, were reported from Ogasawara Islands for the first time.

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Overwintering egg cases of two praying mantises, Tenodera aridifolia and T. angustipennis, were collected in southern Osaka Prefecture after their hatching season in early summer, and reared under quasi-natural conditions. Adults of Thaumaglossa hilleri emerged from 5 and 2 out of 10 egg cases of respective T. aridifolia and T. angustipennis in the autumn, and these were considered as the 1st generation. Thus, Th. hilleri is assumed to be bivoltine ; larvae of the 1st generation feed on hatched egg cases of praying mantises and develop into adults in the autumn, while those of the overwintering generation feed on overwintering egg cases and emerge in the spring. Since adults of Th. rufocapillata were observed to have emerged together with the congeneric Th. hilleri from a single egg case of T. aridifolia, these two species of the dermestids may be competitive in larval stage from the 1st generation.

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