In recent years, interest in edible insects has increased, and the number of farmers that breed insects in large quantities is increasing. As a result of mass breeding of insects, the damage from diseases and mites is also increasing. The chief aims of the investigation reached during some work are briefly stated. In this experiment, the kinds of mites and the environment of mites occurring in beneficial insects were investigated. The species with the highest frequency were Sanacassania sp., Tyrophagus sp., Canestriniidae and Gaeolaelaps sp.. Sanacassania sp. and Canestriniidae of them are reported as parasitic mites on beneficial insects.

This study were performed in Tropical Plant Resources Research Center of Korea National Arboretum, Pocheon, Korea to assess the effects of beneficial insects against Pseudococcus comstocki (Kuwana) on Phyllanthus acidus (Linnaeus) Skeels and Tetranychus urticae Koch on Acalypha wilkesiana Muell Arg. We investigated the density of leaf-feeding P. comstocki at intervals of approximately 2 weeks and T. urticae at intervals of approximately 1 weeks after introducing their natural enemies; Chrysoperla nipponensis (Okamoto) and Phytoseiulus persimilis Athias-Henriot. The densities of P. comstocki were suppressed 80.0% (after 4 weeks) and 97.5% (after 8 weeks) after introducing C. nipponensis. The densities of T. urticae were suppressed 84.1% (after 4 weeks) and 99.6% (after 6 weeks) after introducing P. persimilis.

해충의 생물적 방제 인자로서 주목받고 있는 곤충병원선충(Steinernema carpocapsae)과 이들의 공생세균(Xenorhabdus nematophilus)이 유용곤충인 누에(Bombyx mori)와 그물등개미(Pristomyrmex pungens)에 상이한 독성을 보였다. S. carpocapsae는 누에에 대해 매우 높은 살충력(반수치사농도: 4IJs (감염태 유충수)/ml)을 보이는 반면, 그물등개미에 대해서는 매우 약했다. (반수치사농도: >150,000 IJs/ml). 반면에 X. nematophilus는 그물등개미에 대해 높은 경구독성(반수치사농도: 1.4103cfu (콜로니 형성수)/ml)을 보였으나, 누에에 대해서는 낮았다. (반수치사농도: > cfu/ml). 또한 실험동물 랫드(Rattus norvegicus)에 S. carpocapsae와 X. nematophilus를 강제로 경구투여 한 결과 시험 전기간(21일)동안 치사개체는 없었으며, 내부 장기에서 처리한 공생세균과 선충은 발견되지 않았다.