# Developing heterospecific sterile insect technique for pest control: insights from the spotted wing fly Drosophila suzukii

## TL;DR

Scientists tested using sterile fruit flies from a different species to reduce the offspring of the invasive pest Drosophila suzukii.

## Contribution

This study introduces a novel pest control approach using heterospecific sterile insect technique (h-SIT) with Drosophila melanogaster to target D. suzukii.

## Key findings

- Irradiation caused high sterility in Drosophila melanogaster males without affecting their lifespan.
- Irradiated Drosophila melanogaster males successfully courted and mated with Drosophila suzukii females.
- Irradiated males significantly reduced the number of offspring produced by Drosophila suzukii females.

## Abstract

Reproductive interference (i.e. sexual interaction between males of one species and females of another species that reduce the fitness of one or both the interacting individuals) is an important species interaction significantly affecting population dynamics and persistence. However, its exploitation in pest control remains overlooked. Here, we investigated the possible integration of reproductive interference into the sterile insect technique (SIT) to develop a heterospecific SIT (h‐SIT). Under this approach, contrary to the classic SIT, sterile heterospecific males from closely related, nonpest species are released to compete with the pest population for mates. To this end, we focused on the invasive pest species Drosophila suzukii and used D. melanogaster as the control species. First, we investigated the effect of irradiation on D. melanogaster sterility and longevity. Then, we tested the mating performance of irradiated males and their ability to reduce the D. suzukii fitness.

We found by microcosm experiments that: (i) irradiation induced high levels of D. melanogaster male sterility without reducing longevity; (ii) irradiated D. melanogaster males court D. suzukii females as much as D. suzukii males do, and they couple, mate with and inseminate heterospecific females; (iii) irradiated D. melanogaster males significantly reduce the offspring of D. suzukii females under two different species ratios.

Our results provide the first foundations for the development of a h‐SIT against D. suzukii, an approach which can be tested against other groups of pest species. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Irradiated Drosophila melanogaster males successfully court and mate with D. suzukii females and significantly reduce numbers of D. suzukii offspring under different species ratios.