Efficacy of some native entomopathogenic nematodes against the alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), and the lucerne beetle, Gonioctena fornicata (Brüggemann) (Coleoptera: Chrysomelidae), adults under laboratory conditions

Abstract

Background Entomopathogenic nematodes (EPNs) have more important role in biological control of economic insect pests. The effect of native EPNs on adults of the lucerne beetle, Gonioctena fornicata (Brüggemann, 1873) (Coleoptera: Chrysomelidae), and the alfalfa weevil, Hypera postica (Gyllenhal, 1813) (Coleoptera: Curculionidae), which are important alfalfa pests in Turkey and around the world, was investigated. Results Dose-mortality assays were carried out with 5 isolates [Steinernema carpocapsae (Weiser, 1955) (Nematoda: Steinernematidae) (Black sea isolate), S. feltiae Filipjev, 1934 (isolate 09-31), Heterorhabditis bacteriophora Poinar, 1976 (Nematoda: Heterorhabditidae) (isolate 09-43), H. bacteriophora Tokat-Songut, and S. carpocapsae Tokat-Ulas] using doses of 500, 1000, and 2000 IJs ml−1 under the laboratory conditions. Studies showed that all isolates had an effect 90% and more at 2000 IJs ml−1 and at the end of 112 h [except, H. bacteriophora (isolate 09-43) and H. bacteriophora Tokat-Songut isolates against H. postica]. In addition, LT30, LT50, and LT90 values at 1000 IJs ml−1 were determined. Conclusions According to the results, G. fornicata adults were susceptible to all isolates tested in the study and H. postica adults were susceptible to the isolates S. carpocapsae (Black sea isolate), S. feltiae (isolate 09-31), and S. carpocapsae Tokat-Ulas. This is the first study conducted in Turkey for the virulence of EPNs against G. fornicata and H. postica.