Population development of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae), under individually- and group-reared conditions

Abstract

The Colorado potato beetle (CPB) is a serious pest of potato in China. To determine the effect of individual-rearing and group-rearing on its population growth and development, we studied its life tables and projected its population growth using the TWOSEX-MS Chart and TIMING-MS Char programs. Results showed that individually-reared CPBs were significantly better than that of group-reared CPBs, in terms of intrinsic rate of increase (0.07), finite rate of increase (1.07), net reproductive rate (39.93), and gross reproductive rate (221.23) compared to that of group-reared treatment (0.05; 1.05; 10.84; and 58.77). Additionally, individually-reared CPB populations had faster development, characterized by shorter generation cycles, and higher female survival rates, which produced more offspring per unit time, compared to the group-reared CPB population. However, in potato fields, the CPB are mostly found in groups and therefore the group-rearing method should be more effective for prediction and possible management of CPB populations. This study serves as a reference for an effective and biological prevention and control of the CPBs.