Effect of nest box use by house wrens ( Troglodytes aedon ) on the control of the spotted‐wing drosophila ( Drosophila suzukii ) in a cherry orchard of Argentina

Abstract

BACKGROUND: Agroecology proposes sustainable practices for pest management. Biological control is usually used as a preferred method. However, biological control is usually focused on arthropods, and there are fewer works that study vertebrates, such as birds, as natural pest controllers. Drosophila suzukii is an important worldwide pest that affects many types of fruit crops. The aim of the present study was to evaluate the common house wren (Troglodytes aedon) as a potential pest controller of D. suzukii. We installed 30 nest boxes in a cherry orchard located in the southeast of Buenos Aires province, Argentina, and monitored the abundance of D. suzukii using plastic bottles baited with an attractant liquid throughout the crop during the reproductive seasons of 2020–2021 and 2021–2022. We evaluate the effect of the number of nestlings, week, and nest box distance on the abundance of total Drosophilid flies and total D. suzukii flies. RESULTS: Lower total fly abundance was observed in the second week for nests with 1–3 nestlings compared to the first week for the same nests. Lower total fly abundance was found in nests with 4–6 nestlings at a shorter distance from the nests compared to nests with 1–3 nestlings at a greater distance. Likewise, lower D. suzukii fly abundance was observed in sites with 4–6 nestlings during the second week compared to controls without nestlings and nests with 1–3 nestlings during the first week. CONCLUSION: The results indicate that the impact of the house wren on the spotted wing drosophila abundance was only evident when comparing nest boxes with a higher number of older nestlings, suggesting that it may not be a highly effective management strategy on its own, but may assist synergistically with other management tools.