Efficacy of Entomopathogenic Nematode Steinernema feltiae (Filipjev) as a Biological Control Agent of Lentil Weevil, Bruchus lentis, Under Laboratory Conditions

Abstract

Stored-product pests in the family Bruchidae of Coleoptera represent important pests affecting legume seeds. The lentil weevil, Bruchus lentis Froelich (Coleoptera: Chrysomelidae: Bruchinae) is one of the major lentil pests in Iran and in the world. The economic losses caused by this pest on lentil grow up to 40%. Synthetic pesticides are currently the chosen method to protect stored grain from insect damage. However, their widespread use has led to the development of pest strains resistant to insecticides and pest resurgence. In recent years, nonchemical methods, including biological agents are considered safe methods to control the stored grain pests. Positive characteristics of entomopathogenic nematodes as biological control factors of arthropod pests, introduce them as an appropriate option for controlling the integrated pest management of lentil weevil. In the present study, an isolate of entomopathogenic nematode, Steinernema feltiae, isolated from soils around Yasouj and based on morphological traits and morphometric data were identified. Adult insects of lentil weevil were exposed to concentrations of 0; 500; 1,000; 2,000 and 3,000 infective juvenile/ml of distilled water at different temperatures (20, 23, 26 and 29 °C). Insects were placed on filter paper impregnated with 1 ml of nematode suspension in Petri dishes for three days. Mortality of the insects was recorded every 24 hours. The highest mortality was recorded after 72 hours, which represented 79.40%, at the concentration of 3,000 infective juvenile at 26 °C.