Biological Control Using Egg Parasitoids

Egg parasitoids are minute hymenopteran insects that specialise in depositing eggs within or upon the eggs of pest species, thereby interrupting pest development and reducing population growth. They have become central to integrated pest management programmes in horticultural, arable and forestry systems, owing to their high host specificity and minimal non-target effects. Successful implementation often involves mass rearing under controlled conditions, followed by strategic releases—either inoculative, to establish a self-sustaining population, or inundative, to achieve rapid suppression. The efficacy of egg parasitoids is influenced by environmental factors (temperature, humidity), host egg age and density, and the parasitoid’s dispersal behaviour and functional response. Recent innovations in rearing media, tracking dispersal and deployment technologies have enhanced cost-effectiveness and reliability. As global agriculture seeks sustainable alternatives to chemical insecticides, egg parasitoids continue to offer a scalable, environmentally benign approach to long-term pest regulation.

Research from Nature Portfolio

A novel high-throughput assay has been introduced in which groups of micro-wasps are tracked in a double-spiral maze, yielding precise estimates of diffusion coefficients and enabling scalable studies of spatial propagation under laboratory conditions. This innovation bridges the gap between small-scale assays and field trials, streamlining dispersal research for species used in biocontrol programmes. Foundational work on Trichogramma pretiosum has demonstrated differential parasitism and emergence rates on alternative hosts, revealing host-specific preferences linked to egg age and species origin, thereby informing targeted release strategies for polyphagous pests. Complementary research on Trichogramma dendrolimi has validated an artificial medium for up to twenty generations of rearing, maintaining key fitness parameters and offering a practical substrate for mass production of egg parasitoids for augmentative release.

Biological Control Using Egg Parasitoids publication trend

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

Technical terms

Egg parasitoid: A wasp that lays its eggs in or on the eggs of host insects, with larval development resulting in host death.

Inundative release: The mass release of biocontrol agents to suppress pest populations rapidly without the need for establishment.

Functional response: The relationship between host density and the rate at which a parasitoid attacks hosts.

Diffusion coefficient: A metric quantifying the rate and pattern of spatial spread of organisms in an environment.

Host specificity: The degree to which a parasitoid exploits a narrow range of host species, minimising non-target impacts.

References

1. A double-spiral maze and hi-resolution tracking pipeline to study dispersal by groups of minute insects. Scientific Reports (2023).
2. Biological characters of Trichogramma dendrolimi (Hymenoptera: Trichogrammatidae) reared in vitro versus in vivo for thirty generations. Scientific Reports (2017).
3. The Use of UAS to Release the Egg Parasitoid Trichogramma spp. (Hymenoptera: Trichogrammatidae) Against an Agricultural and a Forest Pest in Canada. Journal of Economic Entomology (2021).
4. Trichogramma ostriniae Is More Effective Than Trichogramma dendrolimi As a Biocontrol Agent of the Asian Corn Borer, Ostrinia furnacalis. Insects (2022).
5. Effects of Helicoverpa armigera Egg Age on Development, Reproduction, and Life Table Parameters of Trichogramma euproctidis. Insects (2021).