Qian Zhao1, Lu Ye1, Zhaolei Wang1, Yanfang Li2, Yang Zhang2, Nemat O Keyhani3, Zhen Huang1,3. 1. Key Laboratory of Bio-Pesticide Creation and Application of Guangdong Province, Department of Entomology, College of Plant Protection, South China Agricultural University, Guangzhou, China. 2. Plant Protection Research Institute, Guangdong Academy of Agricultural Science, Guangzhou, China. 3. Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA.
Abstract
BACKGROUND: The brown planthopper (Nilaparvata lugens) is an insect pest of rice (Oryza sativa) that is distributed worldwide and is responsible for significant crop yield losses. Of particular concern, N. lugens has developed high resistance to several commonly used insecticides. The entomopathogenic fungus, Isaria javanica, offers an alternative to insecticides for the control of rice plant pests. RESULTS: We show that I. javanica caused high mortality of N. lugens nymphs and reduced the survival and fecundity of newly emerged adults in I. javanica-treated insects. I. javanica persisted on plants up to 17 days after its inoculation under greenhouse conditions carried out in summer and autumn. Rice metabolites supported conidial germination and mycelia growth of I. javanica. A granular formulation of I. javanica conidia controlled N. lugens populations in a field experiment. The granular formulation promoted fungal survival and growth in the field up to 28 days post inoculation, resulting in increased fungal persistence and greater pest control coverage. CONCLUSION: These data indicate that a granular formulation of I. javanica is able to control N. lugens populations in rice fields. Therefore, this granular formulation can be an alternative to insecticides and can be used in organic fields.
BACKGROUND: The brown planthopper (Nilaparvata lugens) is an insect pest of rice (Oryza sativa) that is distributed worldwide and is responsible for significant crop yield losses. Of particular concern, N. lugens has developed high resistance to several commonly used insecticides. The entomopathogenic fungus, Isaria javanica, offers an alternative to insecticides for the control of rice plant pests. RESULTS: We show that I. javanica caused high mortality of N. lugens nymphs and reduced the survival and fecundity of newly emerged adults in I. javanica-treated insects. I. javanica persisted on plants up to 17 days after its inoculation under greenhouse conditions carried out in summer and autumn. Rice metabolites supported conidial germination and mycelia growth of I. javanica. A granular formulation of I. javanica conidia controlled N. lugens populations in a field experiment. The granular formulation promoted fungal survival and growth in the field up to 28 days post inoculation, resulting in increased fungal persistence and greater pest control coverage. CONCLUSION: These data indicate that a granular formulation of I. javanica is able to control N. lugens populations in rice fields. Therefore, this granular formulation can be an alternative to insecticides and can be used in organic fields.