Influence of climate regime on clover root weevil adult survival and physiology

Abstract

Clover root weevil adults collected from the field were held in four contrasting temperature moisture and feeding regimes for a period of 10 weeks Temperature was the main factor inducing changes in adult wing muscle development and egg production Egg production from females held in the moist winter regime (10C 816 h lightdark moist conditions ample food) increased linearly with time with 90 of females fully reproductive at 10 weeks In contrast when held in the hot drought regime (20C 168 h lightdark dry conditions intermittent food) the oviposition rate decreased logarithmically with 32 of females fully reproductive at 10 weeks Overall adult mortality was lower in the moist regimes (17) than the drought regimes (29) Wing muscle development differed between regimes ranging from 4 of adults with fully developed wing muscles in the moist winter regime to 35 in the hot drought regime Clover root weevils are likely to oviposit throughout winter in most of New Zealand but warm dry summers will prevent a summer larval generation