Efficacy and profitability of five insecticides for the control of the stem girdler, Analeptes trifasciata (Coleoptera: Cerambycidae) on cashew

Current management practices for Analeptes trifasciata Fabricius (Coleoptera: Cerambycidae) on cashew are cultural, however, these are largely inadequate. Thus compelling the indiscriminate application of unapproved chemicals for its control in Nigeria. As part of a coordinated research effort to develop and integrate a diverse array of control options, we screened the effects of imidacloprid, dimethoate, chlorpyrifos, thiamethoxam and cypermethrin on A. trifasciata management on cashew by laboratory and field trials carried out in 2018 and 2019. The marginal rate of return for each insecticide was calculated to determine the cost-benefit ratio. In the laboratory toxicity trial, all the insecticides showed a dose dependent effect and caused significantly higher insect mortality compared to the control. Thiamethoxam 25WG significantly reduced A. trifasciata populations, improved yield and recorded stable marginal returns of 6.24% and 8.52% in the first and second year respectively. The findings and implications of this study will prove useful as a part of an integrated management system for A. trifasciata.