Overwintering population of the rice stink bug Niphe elongata (Hemiptera: Pentatomidae) on mondo grass, Ophiopogon japonicus

Abstract The rice stink bug Niphe elongata (Dallas) (Hemiptera: Pentatomidae) is a serious pest of rice in central and western Japan, causing grain sterility and grain surface discoloration. Effective management of this pest requires knowledge of its overwintering habitats and the seasonal movements of overwintering adults. We surveyed potential habitats of the overwintering population of N. elongata on several plant species in Tsukuba, Ibaraki Prefecture, Japan, in February. Adults were found in high densities on clumps of mondo grass ( Ophiopogon japonicus ; Asparagales: Asparagaceae). Over the following 2 years, we monitored the seasonal occurrence of adults on mondo grass and in rice fields. Adults were present on mondo grass from September to early July, with peak densities in early autumn and late spring. These findings indicate that mondo grass is a habitat for N. elongata during the overwintering period, mainly in autumn and late spring. Mondo grass is a promising monitoring site for overwintering populations to predict subsequent infestations in rice fields. In early autumn, adults appeared in late-season rice fields and their density on mondo grass increased, suggesting that they migrated to mondo grass for overwintering. In early summer, light trap catches suggested that overwintering adults dispersed from these sites then.