Field Suppression of Spotted Wing Drosophila (SWD) (Drosophila suzukii Matsumura) Using the Sterile Insect Technique (SIT)

Abstract

Drosophila suzukii (spotted wing drosophila—SWD) is an economically important pest of soft and stone fruit worldwide. Control relies on broad-spectrum insecticides, which are neither fully effective nor environmentally sustainable. The sterile insect technique (SIT) is a proven, effective and environmentally friendly pest-management tool. Here, we investigated, for the first time, the potential of using SIT to control D. suzukii in field conditions without physical barriers that limit insect invasion. A proprietary method of rearing and irradiation with X-rays was used to obtain males that were > 99% sterile. Sterile males were released twice per week from April to October 2021 on a site in Kent, UK, where everbearing strawberries were grown in open polytunnels. The infestation of wild female D. suzukii was monitored weekly using red sticky traps with dry lure at the treated site and at two similar control sites that did not receive sterile male releases. Releases of sterile males suppressed the wild female D. suzukii population by up to 91% in comparison with the control sites. We thus demonstrated the feasibility of SIT to achieve season-long control of D. suzukii using early, sustained and dynamically targeted releases of sterile males. This provides a promising environmentally friendly method to control this important pest.

The effects of non‐crop habitat on spotted wing drosophila (Drosophila suzukii) abundance in fruit systems: A meta‐analysis

“…Consistent releases of sterile males could outcompete fertile males with the aim of reducing populations of D. suzukii in the crop. This method has already been shown to significantly reduce numbers of D. suzukii in open strawberry polytunnels by 91% throughout the season when compared with untreated control sites (Homem et al, 2022). This technique could be used with repeated releases in non-crop habitats to intercept newly emerged females from wild hosts before they enter the crop (Nikolouli et al, 2018).…”

The Sterile Insect Technique can efficiently reduce the reproduction of the spotted wing drosophila (Drosophila suzukii) in strawberry

“…Recently. Homem et al (2022) indeed reported that sterile releases hampered D. suzukii population growth in a (single) large greenhouse, which was compared to two control greenhouses. This earlier work is particularly impressive for the scale of the assay and the number of insects produced and released.…”

“…Standard statistical methods could hence be deployed ; they show, with little doubt, that the SIT is efficient at reducing D suzukii reproduction. This occurred even at a fairly low sterile/fertile ratio of 5, much lower than that used by Homem et al (2022). Moreover, because the assay was run over less than 1 fly generation (5 days) we could control numerous parameters.…”

“…Several key results have been obtained leading to lifting the locks for crucial steps in the development of SIT: mass-rearing technique (Aceituno-Medina et al, 2020;Sassù et al, 2019a), irradiation dose and stage of irradiation of the insect (Lanouette et al, 2017;Sassù et al, 2019b), transportation (Enriquez et al, 2021). Furthermore, a first success of SIT against D. suzukii has been obtained in 2022, in strawberry grown in greenhouse, giving confidence in this technique to control D. suzukii (Homem et al, 2022). Time is hence ripe for field and semi-field validations of the efficacy of this promising method.…”

Feriez-vous du mal à une mouche ? Une introduction à Drosophila suzukii et aux méthodes alternatives pour contrôler cette espèce invasive.

“…This dose can be decreased if the adults are infected with Wolbachia bacteria (Nikolouli et al, 2020). Recently, releases of sterile males suppressed the wild female SWD population by up to 91% (Homem et al, 2022). However, that did not stop the females from damaging the fruits via oviposition allowing the infection of the fruit by bacteria or fungi (Cini et al, 2012;Lanouette et al, 2017).…”