Entomopathogenic Nematodes in Biological Pest Control

Entomopathogenic nematodes (EPNs) are microscopic roundworms that parasitise and kill insect pests, offering a sustainable alternative to chemical pesticides. Two genera, Steinernema and Heterorhabditis, harbour mutualistic bacteria that release toxins within the insect haemocoel, causing rapid host mortality. EPNs locate hosts through a combination of chemical and thermal cues, infect predominantly soil-dwelling stages of key pests and reproduce within cadavers, releasing a new cohort of infective juveniles (IJs). Their broad host range, compatibility with diverse cropping systems and low environmental impact have driven global adoption in integrated pest management programmes. Critical factors influencing efficacy include soil texture, moisture and temperature, as well as interactions with indigenous soil organisms. Advances in production, formulation and application technology have enhanced field persistence, while studies of EPN–host interactions and chemical ecology continue to refine deployment strategies. EPNs are now applied across orchards, vegetables, turfgrass and root crops, demonstrating both preventative and curative control under varied agroecosystems.

Research from Nature Portfolio

Recent investigations have elucidated how EPNs perceive and respond to host-derived chemical signals. Studies have identified specific volatile compounds emitted by infected and uninfected insect hosts, which modulate IJ behaviour. Certain alcohols and ketones, released in a temporally dynamic manner, act as repellents to conspecific IJs, driving dispersal from depleted resources, while other compounds attract naïve hosts. This work reveals complex communication networks in the soil environment, with implications for optimising EPN application timing and improving host encounter rates. Insights into the molecular pathways underlying host-seeking and avoidance behaviour suggest targets for enhancing nematode efficacy through selective breeding or chemical augmentation.

Entomopathogenic Nematodes in Biological Pest Control publication trend

The graph below shows the total number of articles in entomopathogenic nematodes in biological pest control across all publications each year (not limited to Nature Index journals).

Technical terms

Entomopathogenic nematode: A soil-dwelling roundworm that infects and kills insect hosts in conjunction with symbiotic bacteria.

Infective juvenile (IJ): The non-feeding, developmentally arrested stage of an EPN adapted for host seeking and infection.

Symbiotic bacteria: Mutualistic bacterial partners, typically Xenorhabdus or Photorhabdus species, released by EPNs to produce toxins and nutrients within the insect cadaver.

Excretory/secretory products (ESPs): Proteins and metabolites released by activated IJs that contribute to host immunosuppression and tissue degradation.

Integrated pest management (IPM): A coordinated pest control strategy that combines biological, cultural, physical and chemical tools to minimise economic, health and environmental risks.

References

1. Can Entomopathogenic Nematodes and Their Symbiotic Bacteria Suppress Fruit Fly Pests? A Review. Microorganisms (2023).
2. Compatibility of Entomopathogenic Nematodes with Chemical Insecticides for the Control of Drosophila suzukii (Diptera: Drosophilidae). Plants (2024).
3. Entomopathogenic Nematodes in Sustainable Food Production. Frontiers in Sustainable Food Systems (2020).
4. Activated entomopathogenic nematode infective juveniles release lethal venom proteins. PLOS Pathogens (2017).
5. Nematobacterial Complexes and Insect Hosts: Different Weapons for the Same War. Insects (2018).
6. Host seeking parasitic nematodes use specific odors to assess host resources. Scientific Reports (2017).