Related Experiment Video
Updated: Aug 14, 2026
Isolation and Selection of Entomopathogenic Fungi from Soil Samples and Evaluation of Fungal Virulence against Insect Pests
Published on: September 28, 2021
Compatibility of entomopathogenic nematodes with fipronil
1Departamento de Biología Animal, Vegetal y Ecología, Facultad de Ciencias, Universidad Autónoma de Barcelona, Bellaterra, 08193 Barcelona, Spain. Fernando.Garcia@uab.es
Abstract:
The survival and infectivity of infective juveniles (IJs) of three species of entomopathogenic nematodes, Steinernema carpocapsae Weiser, S. arenarium (Artyukhovsky) (Rhabditida: Steinernematidae) and Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae), were determined after exposure to different concentrations (250, 500, 1000 and 2000 ppm) of fipronil, an insecticide acting on the GABA receptors to block the chloride channel. Heterorhabditis bacteriophora was very tolerant to all concentrations of fipronil, with the highest mortality of 17% being observed at 2000 ppm of fipronil after 72 h exposure. Steinernema carpocapsae showed a similar response, with the highest mortality of 11.25% of IJs being observed after 72 h exposure to 2000 ppm of fipronil. Steinernema arenarium was, however, more sensitive to fipronil, and at 2000 ppm mortality rates of 94.6% and 100% were observed after 24 and 72 h, respectively. Fipronil had negligible effects on the infectivity of the three nematode species tested. The IJs which survive exposure to all concentrations of fipronil tested can infect and reproduce in Galleria larvae. The moderate effects on entomopathogenic nematodes of a lower fipronil concentration (250 ppm) and the field rates (12-60 ppm) of fipronil used as insecticide, suggest that direct mixing of entomopathogenic nematodes and fipronil at field rates is a viable integrated pest management option.
Insights
Entomopathogenic nematodes (EPNs) show varying tolerance to fipronil insecticide. While Heterorhabditis bacteriophora and Steinernema carpocapsae are tolerant, Steinernema arenarium is sensitive, but infectivity remains largely unaffected, suggesting integrated pest management potential.
Area of Science:
- Agricultural Entomology
- Nematology
- Pesticide Toxicology
Background:
- Entomopathogenic nematodes (EPNs) are vital biological control agents.
- Fipronil is a broad-spectrum insecticide targeting GABA receptors.
- Assessing compatibility of EPNs with insecticides is crucial for integrated pest management (IPM).
Purpose of the Study:
- To evaluate the survival and infectivity of three EPN species exposed to fipronil.
- To determine the impact of fipronil concentrations on different nematode species.
- To assess the potential of combining EPNs with fipronil in IPM strategies.
Main Methods:
- Exposure of infective juveniles (IJs) of Steinernema carpocapsae, Steinernema arenarium, and Heterorhabditis bacteriophora to fipronil concentrations (250–2000 ppm).
- Mortality assessment after 24 and 72 hours of exposure.
- Infectivity tests using Galleria larvae to evaluate the ability of surviving nematodes to infect and reproduce.
Main Results:
- Heterorhabditis bacteriophora and Steinernema carpocapsae exhibited high tolerance to fipronil, with mortality below 17% at 2000 ppm.
- Steinernema arenarium showed increased sensitivity, with mortality reaching 94.6% at 2000 ppm after 24 hours and 100% after 72 hours.
- Fipronil exposure had negligible impact on the infectivity of surviving EPNs across all tested concentrations.
Conclusions:
- EPN species exhibit differential tolerance to fipronil.
- The infectivity of surviving EPNs is largely preserved, even after fipronil exposure.
- Combining EPNs with fipronil at field application rates presents a viable IPM option.
