Abstract BACKGROUND Drosophila suzukii is an invasive pest that causes major economic losses in berry production worldwide. Increasing concerns regarding insecticide resistance and environmental impacts associated with intensive insecticide use have stimulated interest in plant‐derived bioactive compounds as alternative sources of bioactive compounds for insect management. In this study, we evaluated the effects of isoquinoline alkaloids and alkaloid‐rich extracts from Berberis darwinii on oviposition and survival of D. suzukii under controlled laboratory conditions. RESULTS Alkaloidal extracts obtained from roots, stems, and leaves were evaluated together with berberine, palmatine, and their binary mixtures. Root extracts, characterized by high concentrations of berberine and palmatine, produced the strongest biological responses, reducing oviposition by more than 80% at the highest concentration and producing the lowest median lethal dose (LD₅₀) values across developmental stages (4.23 mg L −1 for eggs, 3.77 mg L −1 for larvae, and 0.50 mg L −1 for adults), compared with purified berberine (44.00, 83.14, and 7.03 mg L −1 , respectively). Palmatine also showed high larvicidal activity (LD₅₀ = 2.10 mg L −1 ), whereas leaf extracts exhibited comparatively weak biological activity consistent with their low alkaloid concentrations. Concentration‐dependent reductions in oviposition and increases in egg, larval, and adult mortality were consistently observed across treatments. CONCLUSION The results demonstrate that alkaloid‐rich extracts and protoberberine alkaloids from B. darwinii affect oviposition and survival across developmental stages of D. suzukii under laboratory conditions. Root extracts and palmatine‐rich treatments produced the strongest responses, highlighting the importance of tissue‐specific alkaloid accumulation in determining biological activity. These findings support further investigation of B. darwinii as a source of plant‐derived bioactive compounds affecting D. suzukii , although additional studies addressing environmental stability, non‐target effects, and field efficacy are required before practical pest management applications can be considered. © 2026 Society of Chemical Industry.
Chacón-Fuentes et al. (Tue,) studied this question.