Entomopathogenic nematodes for control of potato tuber moth (Phthorimaea operculella [Zeller], (Lepidoptera: Gelechiidae) in infested tubers

The potato tuber moth (PTM), Phthorimaea operculella, is one of the most economically important potato pests worldwide. In the present study, the potential of Steinernema carpocapsae for controlling PTM in infested potato tubers was evaluated and compared with S. feltiae and the pyrethroid alpha-cypermethrin. The results for efficacy percentage showed that S.carpocapsae [72.52 and 65.49% for 12.6 x 10(6) and 6.2 x 10(6) infective juveniles (IJs), respectively] and S. feltiae (69.56% for 12.6 x 10(6) IJs) were as efficient as alpha-cypermethrin (66.76% for10 mg ai L-1). Both concentrations of alpha-cypermethrin and S. carpocapsae showed the least tuber damage with no significant differences (33.5-39.33%), while it was as high as the control (59.26%) in both concentrations of S. feltiae. The median lethal concentration (LC50) value for S. carpocapsae [5.46 (4.41-6.55) IJs per prepupa] was significantly lower than S. feltiae [8.52 (7.12-10.20) IJs per prepupa] which confirms the superiority of S. carpocapsae. These promising findings introduce S. carpocapsae as a part of the potato tuber protection programs for treating the tubers. Accordingly, EPNs can be considered as an appropriate alternative to synthetic chemicals for PTM control.