INSECTICIDAL AND INHIBITORY POTENTIAL OF TWO CHITIN SYNTHESIS INHIBITORS, BUPROFEZIN AND LUFENURON ON OKRA SHOOT AND FRUIT BORER, EARIAS VITTELLA

In this laboratory study, insecticidal and inhibitory potential of two chitin synthesis inhibitors (CSIs) viz. Buprofezin and Lufenuron were evaluated against okra shoot and fruit borer (OSFB). CSIs were applied on three days old larvae through different bioassay methods like topical or direct, okra-dip or indirect and combined (topical + leaf-dip). Data were collected on larval mortality, weight reduction and deformations of larvae and adults. Results showed that larval mortality and weight reduction were clearly dose, application methods and time dependent. In case of both CSIs, the highest mortality was found @ 1.0 ml/L that was followed by 0.75 ml and 0.50 ml/L respectively. Likewise, the highest body weight reduction was also found from 1.0 ml/L. In both cases, the concentration 0.5 ml/L was found less effective. In case of application methods, combined bioassay method was found superior than that of rest of the two methods. Moreover, a significant percentage of deformed larvae and adults were developed when 3 days old larvae were treated with either Buprofezin or Lufenuron @ 1.0 ml/L through combined bioassay method. The concentration 0.5 ml/L had very less efficacy on the development of deformed larvae or adults. Therefore, based on the laboratory findings Buprofezin and Lufenuron may be the potential component in IPM programmed, rather than their individual application, for controlling okra shoot and fruit borer as well as production of safe okra.