Sub-lethal effects of Beauveria bassiana (Balsamo) on field populations of the potato tuberworm Phthorimaea operculella Zeller in China

The potato tuberworm Phthorimaea operculella Zeller, is one of the most important potato pests worldwide including China. Several reports indicate that P. operculella could be controlled biologically by the use of beneficial fungus such as Beauveria bassiana (Bals.-Criv) Vuill. However, limited information is available under growing conditions in China. Thus, this study evaluated the sub-lethal effects of B. bassiana on the offspring of P. operculella by the age-stage, two-sex life table. First instar larva of P. operculella were treated with 1×107 conidia mL−1 of the fungus, and several biological parameters were evaluated. The fecundity, duration of the egg stage, all larval stages, pre-adult stage, and total pre-oviposition period, were significantly shorter than the control treatment. Offspring of treated parents, presented a net reproductive rate and mean generation time of 17.43 per day and 24.98 days, respectively, compared to 65.79 per day and 26.51 days for the untreated ones. This study provides basic information to help understanding the potential long-term effects of entomopathogenic fungi on P. operculella.