In response to increasing concerns over the ecological and health-related consequences of synthetic pesticide use, this study investigates the insecticidal efficacy of methanolic extracts derived from Carthamus dentatus against the invasive agricultural pest Halyomorpha halys (Brown Marmorated Stink Bug). Laboratory bioassays revealed a statistically significant, dose- and time-dependent increase in adult mortality over a 10-day exposure period. Notably, Flower Dose 25 (mg/L) consistently induced complete lethality by Day 7 (100.00 ± 0.00%), while Leaf Dose 25 (mg/L) approached similar efficacy by Day 9 (96.60 ± 1.99%). Intermediate mortality levels were recorded for Flower Dose 50 (mg/L) and Leaf Dose 50 (mg/L), whereas the control group exhibited negligible mortality (≤ 0.86 ± 1.33%), underscoring the specificity of the treatment effect. To elucidate the phytochemical basis of this bioactivity, high-performance liquid chromatography (HPLC) was employed to characterise the phenolic composition of the extracts. Rutin was identified as the predominant compound in floral tissues (56.4%), while o-coumaric acid was most abundant in cauline leaves (38.9%). Additional phenolics, including chlorogenic acid, naringin, chrysin, t-ferulic acid, quercetin, and rosmarinic acid, were also detected. These compounds are known to contribute to plant defence through mechanisms such as allelopathy, UV protection, and anti-herbivory activity. Collectively, the findings highlight the potential of C. dentatus methanolic extracts as a promising botanical alternative for the sustainable management of H. halys populations.
BAŞ et al. (Tue,) studied this question.