Efficacy of Entomopathogenic Nematode, Steinernema carpocapsae and its Interaction with Beauveria bassiana against Pieris rapae L. (Lepidoptera: Pieridae)

Pieris rapae L. is one of the most economically important pests of Brassicaceae causing extensive defoliation of plants. Entomopathogenic fungi and nematodes are promising biological control agents. The virulence of each of them tested alone against 4th instar larvae and pupa of P. rapae. The entomopathogenic fungi, Beauveria bassiana showed efficiency against 4th instar larvae and pupae with LC50: 28.857x103 and 175.406x103 spore/ml, respectively. Also, the entomopathogenic nematode, Steinernema carpocapsae was revealed efficacy against 4th instar larvae and pupae with LC50: 18.148 and 38.96 IJs/larva and pupa, respectively. In addition, the interaction of S. carpocapsae with Beauveria bassiana against P. rapae larvae was studied. An antagonistic effect was clearly seen when S. carpocapsae nematode was applied immediately after the B. bassiana. However, the synergistic or the additive effect was seen when the application of the EPNs 12h after their treatment with B. bassiana.