The use of biological agents to control Megalurothrips usitatus (Bagnall) in common bean crop (Phaseolus vulgaris L.)

Abstract

The common bean (Phaseolus vulgaris L.) is a crucial crop, particularly in Honduras, where it is considered a primary source of nutrients and income. Recently, the invasive thrips species Megalurothrips usitatus has emerged as a key pest in legumes, causing severe damage to bean crops in the region. Chemical control methods have proven unsustainable due to the pest s rapid development of resistance, highlighting the need for sustainable and economically feasible alternatives. This study evaluated the efficacy of biological control agents, including Amblyseius swirskii, Orius insidiosus, entomopathogenic fungus Beauveria bassiana, and Spinetoram insecticide against both the larval and adult stages of M. usitatus under greenhouse and laboratory conditions. A Completely Randomized Design (CRD) was used with five treatments (including an untreated treatment) and four replicates. Laboratory trials demonstrated that both Spinetoram and O. insidiosus effectively controlled larvae within the first 48 and 72 hours after release, with O. insidiosus showing and Spinetoram showing a complete reduction. Greenhouse trials confirmed these findings, showing greater larval reductions with O. insidiosus and Spinetoram. For adults, O. insidiosus significantly reduced M. usitatus populations, achieving 100% consumption of adults in two sampling dates. Statistical analysis, including ANOVA and DUNCAN tests, revealed differences (P ? 0.05) among treatments, indicating better control with A. swirskii and O. insidiosus compared to the untreated treatment and B. bassiana treatments. These results suggest that integrating A. swirskii and O. insidiosus into pest management strategies could offer a viable solution for controlling M. usitatus in common bean crops, reducing dependence on chemical pesticides, and promoting more sustainable agriculture practices in Honduras.