Efficacy of a native entomopathogenic nematode Heterorhabditis bacteriophora (isolate Z-1) against potato tuber moth (Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae) in Turkey

Abstract

Background Potato tuber worm (PTM) [Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae)] is one of the most significant and widespread pests of potato. PTM damages potatoes both in the field and in potato storage areas. Control of the pest is getting harder as it is developing resistance to pesticides. Several entomopathogenic nematode (EPN) species have been reported to successfully control numerous agricultural pests worldwide. The main aim of the study was to isolate native nematode/s as a biological control agent against P. operculella. Morphometric measurements of the infective juvenile (IJ) and sequencing and characterization of the internal transcribed spacer (ITS) region was used to identify the nematode isolate to species level. The efficacy of EPN isolate Z-1 obtained from Zonguldak province, Turkey was tested against different life stages of the pest. Experiments were conducted in 150 ml plastic pots containing sterile soil mixture. Four EPN concentrations (i.e., 0, 250, 500 and 1000 IJs/ml) were applied to the soil. Data relating to the mortality of different life stages were collected daily till 6 days after inoculation. Results Molecular analyses based on the ITS sequence and morphometric data revealed that isolate Z-1 was Heterorhabditis bacteriophora. Mortality rates of PTM larvae exposed to 250, 500, and 1000 IJs/ml concentrations of native EPN were 62.9 ± 9.8, 74.0 ± 3.7, and 92.5 ± 3.7%, respectively. There were non-significant differences among tested EPN concentrations for pupal mortality and the highest concentration (i.e., 1000 IJs/ml) caused 25.6% mortality. Conclusions The results revealed that the native H. bacteriophora isolate was effective against late-stage larvae of PTM under laboratory conditions. Therefore, it can be used as an alternative management option of the pest.

Virulence of Entomopathogenic Nematodes and their Symbiotic Bacteria against Insect Pests, with Special Reference to Agrotis ipsilon (Lepidoptera: Noctuidae): A Comprehensive Review.

“…Also, Abd El-Motaalet al (2021) found that the mortality rate increased as the concentration of IJs increased. In Turkey, a recent study by Barış et al (2023) indicated that the last instar larvae of Ph. operculellawere highly susceptible to native EPN H. bacteriophora (isolate Z-1), as well as larvae and pupae mortalities increased with the increasing concentration of EPN.…”

“…Pupae of L. vanillana were less susceptible than larvae to the infection with S. yirgalemense and S. jeffreyense (Du Preez et al, 2021). Recently, Barış et al (2023) indicated that the last instar larvae of Ph. operculellain Turkey were highly susceptible to native H. bacteriophora (isolate Z-1).…”

Low Energy Trap with Light Emitting Diode for Increased Attraction of <i>Phthorimaea operculella</i> Zeller

“…Control of the pest is increasingly difficult as it develops resistance to pesticides. Several entomopathogenic nematode species (EPN) have been reported to successfully control numerous agricultural pests worldwide (Barış et al, 2023).…”