THE RELATIONSHIP BETWEEN INSECT GROWTH REGULATORS WITH JUVENILE HORMONE ACTIVITY AND INSECT FEEDING BEHAVIOURAL RESPONSE

Abstract

Abstract Five insect growth regulators (IGRs) with juvenile hormone (JH) activity including fenoxy‐carb, methoprene, NC‐170, NC‐184 and NC‐196 were selected to study on the relationship between IGRs and feeding behaviour of the fourth instar larvae of Calospilos suspecta (Warren) and the fifth instar larvae of Ostrinia furnacalis Guenee, by topical and dietary applications as well as “diet column” methods. The results indicated that the antifeeding indices of methoprene, fenoxycarb, NC‐170, NC‐184, NC‐196 and toosendanin against the fifth instar larvae of Ostrinia furnacalis in no‐choice test were ‐37. 7, 14. 6, ‐12. 3, 10. 9, 14. 7 and 62. 2% respectively. Methoprene could stimulate the two species of insects to feed, whereas fenoxycarb had some antifeeding activity, and the effects of all the tested chemicals were different. Therefore, disturbances of IGRs with JH activity on insect feeding behavioural response may be one of the mechanisms of action not to be ignored. Moreover, by comparing “diet column” method with “faeces weight” method, it was suggested that the two methods might be applied in bioassay of antifeeding behaviour.