Resistance of some lentil cultivars against the cowpea beetle, Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae)

Abstract

The cowpea beetle, Callosobruchus maculatus (F.), is one of the detrimental insect pests of legume seeds in field and storage conditions. In the current study, the seeds of five lentil cultivars, Perkouz, Sana, Sepehr, Bileh-Savar, and Gachsaran, were evaluated for their resistance to C. maculatus based on life-table parameters, oviposition preference, and digestive function. The biochemical and physical features of studied cultivars were also evaluated to comprehend their potential correlations with examined pest parameters. In the free-choice experiment, the quantity of eggs deposited on Perkouz was highest, while it was lowest on Bileh-Savar. Developmental times on Bileh-Savar, Gachsaran, and Sepehr were longer than on Perkouz. The beetles fed with Bileh-Savar showed lowest net reproductive rate, intrinsic rate of population increase and finite rate of increase. Fourth-instar larvae exhibited lowest proteolytic and highest amylolytic activity on Bileh-Savar. Among the characteristics of lentil seeds, hardness index, moisture content, as well as starch and protein levels notably affect the population parameters of C. maculatus. Given the results of this investigation, Bileh-Savar is the most resistant cultivar for feeding and population increase of C. maculatus and can be considered in management strategies of this pest.