Effect of Entomopathogenic Nematodes Against Sitophilus granarius (L.) and Sitophilus oryzae (L.) (Coleoptera: Curculionidae)

Due to the increase in population of the world and decrease in cultivation areas, it is necessary to reduce harvest and post-harvest losses of cereals, which are one of the main sources of human nutrition. Various storage pests such as Sitophilus granarius and S. oryzae feed on stored grain products, causing product losses, loss of bread and product quality. Various methods are used to reduce these losses in the storages. In this study, the effects of some entomopathogenic nematodes against the adults of these 2 storage pests were investigated. In this study, 4 isolates of Oscheius tipulae isolated from the Puglia Region of Italy and Steinernema carpocapsae and S. feltiae from the University of Banja Luka (Bosnia and Herzegovina) were used. The experiment was conducted in a completely randomized design, under laboratory conditions at 25±1 ºC, with 4 replications and 2 repeats. Nematodes were used in a concentration of 50 infective larva (IJ) insect-1; Insect mortality rates were determined 4, 8 and 12 days after applications. Equal amounts of distilled water were applied as controls. At the end of the experiment, the highest mortality rates were obtained from the applications of S. carpocapsae isolate; these values are 50%-61.5% for S. granarius and 28.8%-43.82% for S. oryzae. The second successful isolate in terms of efficacy was S. feltiae and mortality rates were 12.5%-38.8% for S. granarius and 6.3%-27.5% for S. oryzae. In applications of O. tipulae isolates, the highest mortality rate was 32.5%.