Behavioral rhythms of three Lepidopteran pests; Mythimna separata,Agrotis ypsilon and Helicoverpa armigera

Author of the article:ZHANG Xing-Guo1** JIA Yi-Fan1 WEN Yang2 ZHANG Yi-Fei1 WAN Gui-Jun1 CHEN Fa-Jun1***

Author's Workplace：1. Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; 2. Agricultural Bureau of Jiyang County, Shandong Province, Jinan 251400, China

Key Words： migratory Lepidoptera insects, population occurrence dynamics, behavioral rhythm trapped by blacklamp, species specificity, forecasting and monitoring

Abstract： [Objectives]  To clarify the behavioral rhythms of migratory populations of three species of Lepidopteran pests; Mythimna separate (Walker), Agrotis ypsilon (Rottemberg) and Helicoverpa armigera (HÜbner), and thereby lay a foundation for studying the migration, and predicting outbreaks of, these pests. [Methods]  The behavioral rhythms of the three species of moths were investigated by trapping with an automatic, black-light trapping device from 2010 to 2011. [Results]  The results show large differences in the dates of first capture and peaks of species’ abundance, and in the number of individual moths trapped daily, and yearly, between 2014 and 2015. First capture dates of M. separata, A. ypsilon and H. armigera were 13, 124 and 71 days earlier, respectively, and the peaks of abundance of these species occurred 41, 44 and 71 days earlier, respectively, in 2015 than in 2014. Total numbers of moths trapped per year were also higher in 2015 than in 2014. Most moths were trapped from 2:003:00 a.m. or 3:004:00 a.m.; all three species had a diurnal rhythm with multiple peaks of activity. These findings confirm previously reported biological characteristics of some nocturnally migratory Lepidopteran moths, such as resting before sunup, and also reflect group effects on the behavioral rhythm of migratory insects during population outbreaks. [Conclusion]  The annual dynamics and daily behavioral rhythms of the three species of M. separata, A. ypsilon and H. armigera had both yearly and species differences. This study can provide a scientific basis for monitoring, forecasting, and providing early warning of outbreaks, of these migratory, insect pests.