6 research outputs found
Identification of rice cultivars resistant to Lissorhoptrus oryzophilus (Coleoptera: Curculionidae), and their use in an integrated management program
The rice water weevil, Lissorhoptrus oryzophilus Kuschel, is the most destructive insect pest of rice in the United States and is a particularly severe pest in Louisiana The current management program for this insect in Louisiana relies heavily on insecticides, most notably the seed treatment fipronil (Icon). Diversification of the management program by incorporation of alternative strategies is needed to improve the effectiveness and long-term stability of the program. In the three experiments reported here, three components of a diversified management program for the rice water weevil in Louisiana - host plant resistance, treatment of seeds with Icon, and the cultural practice of delayed flooding - were investigated. Comparison of the densities of weevil larvae on the roots of several commercial cultivars indicated that the long-grain cultivar \u27Jefferson\u27 was more resistant to infestation by the rice water weevil than the other cultivars. The medium-grain cultivars \u27Bengal\u27, \u27Earl\u27 and \u27Mars\u27 and the long-grain variety \u27Cocodrie\u27 were the most susceptible to infestation. Comparison of yield data from untreated plots and plots treated with Icon indicated that the long-grain cultivars Cocodrie, Lemont, and Jefferson were more tolerant of weevil injury than the other cultivars. A 2-wk delay in flooding was associated with yield benefits in plots not treated with Icon. Treatment of seeds with Icon controlled weevils in all three screening experiments. The implications of these results for the development of an integrated management program for the rice water weevil are discussed. © 2001 Entomological Society of America