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 RC50, value (0.61%) followed by Admiral, Sitara and Runner which exhibited 0.86, 0.97 and 1.06% RC50, values, respectively. Similarly, Silent proved highly effective oviposition-deterrent for adult guava fruit flies as it revealed the minimum ODC50, value (0.59%) followed by Admiral, Sitara and Runner which exhibited 0.6, 0.66 and 1.2% ODC50, values, respectively. However, a comparison of FRD with RC50 and ODC50 values of IGRS expounded that none of the evaluated IGRs would be effective repellent or oviposition-deterrent because RC50 and ODC50 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.