The use of systemic anthranilic diamide and neonicotinoid seed treatments in rice pest management
© 2014 American Chemical Society. The rice water weevil, Lissorhoptrus oryzophilus, is the key insect pest of rice in the United States. Over the last five years, anthranilic diamide and neonicotinoid seed treatments have been introduced into the U.S. rice market for management of rice water weevils and other early and mid-season pests. This chapter reviews several aspects of the use of seed treatments in rice. In a four-year field study involving over 40 commercial fields throughout Louisiana, threshold densities of rice water weevil larvae were exceeded in over 80% of untreated fields. Seed treatments of thiamethoxam, a neonicotinoid, were about as effective as foliar applications of pyrethroids at reducing densities of rice water weevil larvae in commercial fields, while seed treatments containing chlorantraniliprole were significantly more effective than pyrethroids or thiamethoxam. A series of greenhouse studies demonstrated that seed treatments of chlorantraniliprole and thiamethoxam have differential effects on life stages of the rice water weevil. Seed treatment with thiamethoxam reduced survival of adults feeding on leaves of treated plants, and had pronounced effects on egg-laying and early instar survival; chlorantraniliprole seed treatment, in contrast, had no effects on adults and exerted its effects primarily on root-feeding larvae. These differences in biological activities were consistent with patterns of distribution of insecticides in tissues of treated plants: high concentrations of chlorantraniliprole were found in roots of both greenhouse and field-grown plants, while thiamethoxam concentrations were higher in above-ground portions of plants. The greater efficacy of chlorantraniliprole seed treatment in field experiments is probably attributable to the greater persistence of this chemical in rice plants and to the tendency of this chemical to accumulate in root tissues. Standard and reduced rates of chlorantraniliprole seed treatment were compatible with two alternative management practices, shallow flooding and plant resistance, in a small-plot field study. Chlorantraniliprole and neonicotinoid seed treatments had differential effects on other pests of rice, including the fall armyworm, Spodoptera frugiperda and sugarcane borer, Diatrea saccharalis. The ubiquity and severity of the rice water weevil as a pest, the effectiveness of seed treatments against both the rice water weevil and sporadic pests, and the lower impact of seed treatments on key non-target organisms provide solid justification for the use of seed treatments in rice.
Publication Source (Journal or Book title)
ACS Symposium Series
Lanka, S., & Stout, M. (2014). The use of systemic anthranilic diamide and neonicotinoid seed treatments in rice pest management. ACS Symposium Series, 1171, 183-213. https://doi.org/10.1021/bk-2014-1171.ch010