Biocontrol potential of Heterorhabditis bacteriophora Poinar, 1976 (Rhabditida: Heterorhabditidae) HBH hybrid strain against the beet webworm, Loxostege sticticalis L., 1761 (Lepidoptera: Pyralidae)

Abstract

With limits on the use of pesticides, biological control has become increasingly important. Consequently, entomopathogenic nematodes (EPN) are now used widely in biological control. EPNs can potentially be used against beet webworm, Loxostege sticticalis L., 1761 (Lepidoptera: Pyralidae), which established in sunflower-growing areas in Turkiye in 2022. Therefore, the hybrid EPN strain, Heterorhabditis bacteriophora Poinar, 1976 (Rhabditida: Heterorhabditidae) HBH, was assessed for this purpose. The study was conducted in Bursa Uludag University, Faculty of Agriculture, Plant Protection Department, Nematology Laboratory in 2022. Four nematode doses (2, 5, 10 and 20 IJs) were applied to the last instars of L. sticticalis at three temperatures (20, 25 and 30 degrees C). The highest mortality was 97% with 20 IJs dose nematodes at 30 degrees C. LD50 and LD90 of the nematode were determined at all tested temperatures. The lowest LD50 and LD90 were at 30 degrees C; 4.37 and 11.0 IJs, respectively. These results indicated that the HBN strain has potential for control of L. sticticalis.