LABORATORY BIOASSAY FOR INVESTIGATING THE REPELLENT AND OVIPOSITION-DETERRENT IMPACTS OF VARIOUS IGRS ON GUAVA FRUIT FLY, BACTROCERA CORRECTA (DIPTERA: TEPHRITIDAE)

A laboratory bioassay was carried out to assess the repellent impacts of various IGRs on guava fruit fly, Bactrocera correcta (Diptera: Tephritidae). The results reveal that settling response of adult guava fruit fly, percent repellency and percent oviposition-deterrence to treated fruit increased with increasing concentration of all evaluated IGRs. Less number of adult fruit flies settled on fruits treated with Silent® [12 (60%)] followed by Sitara® [13(65%)], Admiral® [13(65%)] and Runner® [13.7(69%)] at their highest concentration used in present study. Repellency test revealed that Silent® explained comparatively maximum repellency (22.3%) followed by Admiral® (19.7%), Sitara® (19%) and Runner® (18%) at their highest concentration used in present study. Probit analysis also demonstrated that Silent® proved highly effective repellent for adult guava fruit flies as it revealed the minimum RC_50 value (0.61%) followed by Admiral®, Sitara® and Runner® which exhibited 0.86, 0.97 and 1.06% RC_50 values, respectively. Similarly, Silent® proved highly effective oviposition- deterrent for adult guava fruit flies as it revealed the minimum ODC_50 value (0.59%) followed by Admiral®, Sitara® and Runner® which exhibited 0.6, 0.66 and 1.2% ODC_50 values, respectively. However, a comparison of FRD with RC_50 and ODC_50 values of IGRs expounded that none of the evaluated IGRs would be effective repellent or oviposition-deterrent because RC_50 and ODC_50 values of Silent®, Admiral®, Sitara® and Runner® were many times higher than their FRD. In conclusion, these IGRs can be used as repellent or oviposition-deterrent for fruit flies at higher dose rates; but it would be better to apply these IGRs for impregnation in impregnated-bagging-technique than foliar application.