2010 年のテンサイにおける飛来性害虫シロオビノメイガの多発生と効果的薬剤の検討

抄録

In the summer and autumn of 2010, a mass outbreak of the beet webworm Spoladea recurvalis in sugar beet occurred throughout the entire sugar beet cultivation area of Hokkaido, the northern island of Japan. Serious damage was incurred in mid-August in the southern area, in mid to late August in the central area and the Tokachi district of the eastern area, and after mid-September in the Okhotsk district of the eastern area. Through field research in the central area, the migration period of adult moths was estimated to be mid-July. The early and/or mass migration of moths in addition to the higher summer temperature suitable for the development of the pest from their immature stages might accelerate the unusual mass occurrence of the pest throughout the year. Several insecticides mainly belonging to organophosphates and synthetic pyrethroids were found to be less effective on middle-to-late instar larvae in both insect dipping and diet dipping experiments. Insect growth regulators, on the other hand, were found to be effective for the control of larvae of the pest on sugar beet fields even under such mass occurrence.