2005 年 2005 巻 52 号 p. 73-76
Only one male adult of Riptortus clavatus and no adults of Piezodorus hybneri, both of which are the most important pests of soybean, were found among the leaf litter samples collected at a copse during the winter season for 14 years to estimate the overwintering adult density of Plautia crossota stali, one of the most important pests of tree fruits. Of the 483 bugs found, 339, 70 (fifith instar), 31 and 19 were P. crossota stali, Poecilocoris lewisi, Acanthosoma denticauda and Sastragala esakii, respectively. The result strongly suggested that the main overwintering site of the two soybean pests might be different from that of P. crossota stali, presumably the soybean pests overwinter at a forest edge or near the roots of dry Japanese pampas grass.