LAUSR

Simple Summary Over a two-year period, the trunk injection method was adopted for the management of Xylotrechus chinensis (Chevrolat) (Coleoptera: Cerambycidae) infesting mulberries. Three conventional insecticides, i.e., fipronil, imidacloprid, and spirotetramat, were injected into their trunks and the number of exit holes was recorded after the application. Abamectin was used as a positive control and untreated trees were selected as controls. In the first year (late April–late June 2021), after the insecticidal applications, the emerging holes of X. chinensis were significantly decreased compared to the holes recorded before the treatment (late April–late June 2020). The same trend was observed with the second round of applications of the method (mid June–mid August 2021), where the number of exit holes (late April–late June 2022) was further reduced, reaching 71.8, 76.1, and 85.6% reductions in the cases of fipronil, imidacloprid, and abamectin, respectively. In contrast, spirotetramat did not cause a significant reduction in the emerging holes of X. chinensis throughout the experimental period. Abstract Xylotrechus chinensis (Chevrolat) (Coleoptera: Cerambycidae) is a serious wood-boring insect of mulberry trees (Morus spp.). Larvae of this species enter the trunk of the tree and feed on woody tissues. Xylotrechus chinensis is endemic in several Asian countries, while, in the last decade, it invaded Europe. In the present work, we evaluated trunk injection against this pest. The systemic insecticides fipronil, imidacloprid, and spirotetramat were used in the trials. Abamectin was used as a positive control since it has been found to be effective for the management of X. chinensis. Imidacloprid and fipronil proved to be highly effective against this species in both years (9.5 and 12.1 exit holes/tree in 2021, 5.0 and 8.8 exit holes/tree in 2022, respectively), while spirotetramat was the least effective. The lowest mean number of exit holes was recorded when abamectin was applied in both years (4.7 exit holes/tree in 2021 and 3.3 exit holes/tree in 2022). The percentage of exit holes was reduced by 76.1, 71.8, and 85.6% in trees treated with imidacloprid, fipronil, and abamectin, respectively, after two years of application, while spirotetramat caused a 37.4% reduction. Trunk injection with imidacloprid, fipronil, and abamectin could be used against X. chinensis for long-term control of mulberry trees.