Effect of temperature and soil moisture on the efficacy of indigenous and imported strains of the entomopathogenic nematode, Heterorhabditis sp. against the black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera/Noctuidae)

Abstract

Background Biotic and abiotic factors influence survival, infectivity, development, reproduction, and activity of the entomopathogenic nematodes (EPNs). EPNs have been used to suppress the soil-inhabitant insects, which applied as a successful biological control agent against the black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera/Noctuidae) larvae, and pupae. Results Studying the effect of different temperatures 20, 25, and 30°C ± 2, and the soil moisture content at 10, 15, and 25% on the susceptibility of two Heterorhabditis sp. strains, Egyptian strain (TAN5) and imported strain (Hb88) against the A. ipsilon 4th and 6th larval instars and 3-day-old pupae was carried out under laboratory conditions. The tested concentrations of the two strains were 30, 60, 120, 240, and 480 IJs/cm2 of soil surface. The mortality rate of 4th instar A. ipsilon larvae was high after Heterorhabditis strain TAN5 treatments at all concentrations, which ranged between (24 and 100%) and (6–100%) at 25°C and 30°C, respectively. At 20°C, Heterorhabditis strain Hb88 recorded higher mortality percentages for A. ipsilon 4th and 6th larval instars and pupae than the indigenous strain TAN5. The soil moisture content of 25% gave the highest mortality rates for the 4th instar larvae of A. ipsilon after treatments of the two strains. The Egyptian Heterorhabditis strain TAN5 was tolerant to the increase in temperature and more tolerant to the change in the water content of the soil than the imported strain Hb88 at all concentrations tested. In a semi-field experiment, Heterorhabditis strain TAN5 at concentrations between (1000–8000 IJs/cm2 of soil surface) showed mortality rates (27–95%) for 4th instar A. ipsilon larvae and (19–81%) for the 3-day-old pupae, respectively. Conclusions Heterorhabditis strains TAN5 can was utilized against the black cutworm of A. ipsilon at the temperatures 25 and 30°C. Heterorhabditis strains TAN5 and Hb88 can be utilized against the black cutworm of A. ipsilon at the soil moisture content from 15 to 25%. In the semi-field experiment, Heterorhabditis TAN5 and Hb88 strains were effective against larvae and pupae of A. ipsilon at high concentrations of the nematodes.

Efficiency of temperature and storage duration on some morphological measurements and reproductive capacity of the entomopathogenic nematode Heterorhabditis bacteriophora Poinar, 1976 (Rhabditida: Heterorhabditidae)’s Turkish HBH hybrid strain

“…Recent studies have mainly focused on the effects of temperature on the efficacy of EPNs on the host, their survival abilities under different temperature conditions, optimal temperature ranges, and longevity at different temperatures (Půža & Mráček, 2007;El-Lakwah & Yousef, 2013;Ulu & Susurluk, 2014;Lephoto & Gray, 2020;Nouh, 2022). However, there is limited research on the effects of long-term exposure to different temperatures on their reproductive capacity, the characteristics of hermaphroditic individuals, and eggs (Griffin, 1996;Boff et al, 2000;Mejia-Torres & Saenz, 2013).…”

Bazı entomopatojen nematodların etkinliğinde kuraklığın rolü

“…Ten larvae were used for each soil moisture level and dose, and all assessments were repeated three times. Typically, no separate control group was established in the study, as previous investigations into the efficacy of the EPNs on the host had utilized a soil moisture level of 10% (Langford et al, 2014;Salame & Glazer, 2015;Dede et al, 2022;Nouh, 2022;. Therefore, the 10% soil moisture employed in this study represents the control group for the experiment.…”

“…However, excessively high soil moisture levels, as in saturated soils, can have detrimental effects on the viability and development of EPNs. Therefore, it is recognized that a balanced relationship between EPNs and soil moisture is essential for their successful function and development (Koppenhöfer et al, 2020;Nouh, 2022).…”

Enzymatic Disturbance in Larvae of The Black Cut Worm, Agrotis ipsilon (Lepidoptera: Noctuidae), by Infection with The Entomopathogenic Nematodes, Steinernema carpocapsae and Heterorhabditis bacteriophora

“…These problems are an incentive to search for alternative, eco-friendly, selective, and effective control measures. Among potential control measures is the use of entomopathogenic nematodes (EPNs), especially against above-ground pests and those are spending a part of their life cycle inside the soil or cryptic habitats (Laznik and Trdan, 2011;Lacey and Georgis, 2012;Shaurub et al, 2016;James et al, 2018;Du Preez et al, 2022;Nouh, 2022). Therefore, EPNs have attracted much interest around the world to study their distribution, virulence, and usage in the integrated pest management (IPM) programs (Çağlayan et al, 2021;Ali et al, 2022) because they are harmless to non-target organisms, humans health and the environment (Odendaal et al, 2015(Odendaal et al, , 2016Gulcu et al, 2017;Kumar et al, 2022;Peçen and Kepenekci, 2022).…”