Managing sucking pests biorationally considering bean aphid, Aphis craccivora Koch. as an example

Abstract

Conventional control of sucking pests infesting various vegetables has several drawbacks. Biorational insecticides are increasingly used for pest management due to their limited side effects. A study involving several biorational compounds, viz. spinosad, buprofezin, Beauveria bassiana, Lecanicillium muscarium and a chemical insecticide, fenitrothion was performed by leaf-dip bioassay to measure their efficacy against the bean aphid, A. craccivora Koch. as a representative of sucking pests. Mortality of aphids against treatment with biorational insecticides was recorded in three replicates under laboratory conditions. The lethal concentration (LC50 and LC90) of the treatments were calculated by probit analysis. Efficacy was concentration and time dependent. Spinosad has been found to be more effective than buprofezin. The spinosad (LC50 = 2582.04 ppm) and buprofezin (LC50 = 543.03 ppm) were found to be approximately 88 and 52 times less toxic than fenitrothion. At 48 h post-treatment (HPT), the highest mortality for spinosad and buprofezin was 66.67 and 60.00%, respectively, and reached 93.33% at 72 HPT. Among the two fungal biopesticides, L. muscarium was more effective than B. bassiana. For both, mortality (80–100%) at the higher concentrations was statistically different than others at 144 and 168 HPT. Thus, biorational compounds, particularly spinosad and L. muscarium, are useful for controlling bean aphids.