اثر کاهشی حشره‌کش گیاهی ماترین بر جمعیت لاروهای شکارگر مگس گل در مزارع گندم استان گلستان

Chemical control is currently the primary method of managing agricultural pests. Insecticides, however, can have detrimental effects on non-target insects, including natural enemies. To minimize the environmental impact of chemical insecticides, efforts are being made to replace them with less hazardous alternatives such as botanical insecticides. However, herbal compounds are not necessarily safe for non-target insects. Matrine is a plant-based insecticide derived from the extract of the shrubby sophora Sophora flavescens, which has recently been registered against some wheat pests. The present study investigated the effect of matrine on larvae of the hoverfly Episyrphus balteatus. Hoverfly species are active predators in wheat fields and play a crucial role in plant pollination and pest biocontrol. The experiment was conducted under field conditions in Ardabil province, Iran. A randomized complete block design with three treatments and four replications was used. The treatments consisted of matrine (2 ml/L), matrine (1.5 ml/L), and a control (water spray). Larval populations were assessed one day before and 3, 7, and 14 days after insecticide application. According to the results, on the third, seventh, and fourteenth days after spraying, matrine 2 ml/L caused 85.2%, 67.0%, and 50.4% reductions in the hoverfly population, respectively, while matrine 1.5 ml/L caused 73.6%, 31.6%, and 21.8% reductions, respectively. Based on the IOBC classification, matrine 2 ml/L was moderately harmful on the third day and slightly harmful on the seventh and fourteenth days. Matrine 1.5 ml/L was slightly harmful on the third and seventh days after spraying and harmless on the fourteenth day. Therefore, it is essential to pay attention to the adverse effects of matrine on beneficial insects and avoid using this botanical compound during the peak population period of hoverflies. This will help protect natural enemies and facilitate pest biocontrol.