天敵温存植物としての障壁作物ソルゴーの役割：ソルゴーおよび露地ナスにおけるアブラムシ類捕食者の発生推移

抄録

Conservation of predator Orius spp. with selective pesticide has shown great promise as an effective Integrated Pest Management （IPM） strategy for managing Thrips palmi and other pests in eggplant fields. Moreover, sorghum barrier crops are promoted as a cultural control for eggplant IPM. To evaluate the potential role of sorghum as a source of natural enemies, we investigated seasonal abundance of aphidophagous predators on sorghum（Sorghum bicolor （L.） Moench）. Significantly more predators were found on ‘Kazetachi’（ late flowering and long culm commercial cultivar） than on other sorghum cultivars, ‘Koutoubun’ （sweet sorghum commercial cultivar） and ‘Akaamakibi’ （sugar rich local variety）. In 2007 the early summer peaks in abundance of syrphid and coccinellid predators commenced on sorghum planted late April and early May only, while late summer peaks in abundance of 4 predator groups were found on sorghum, irrespective of the planting dates. In 2008 a similar peak abundance of predators was found in late July to August. However, predator abundance was extremely low in early summer. In the eggplant field, Aphis gossypii was predominant throughout the growing season, with a minor and major peak in June and July to August, respectively.