Residual effect of dinotefuran and nitenpyram against adult Liothrips wasabiae (Thysanoptera: Phlaeothripidae)

Liothrips wasabiae (Thysanoptera: Phlaeothripidae) is an important insect pest of water wasabi (Eutrema japonicum). The area infested by L. wasabiae becomes black-spotted. Water wasabi requires a long cultivation period of approximately 1.5–2 years. However, chemical insecticides to control L. wasabiae can only be applied a maximum of three times according to the pesticide regulation. Therefore, two insecticides, dinotefuran and nitenpyram, that have been demonstrated to be highly effective, were investigated for their residual effect against L. wasabiae. Results showed that when adult L. wasabiae were released 28 days after insecticide treatment, dinotefuran caused a mortality of 56% compared to 10% with nitenpyram.