Apple weevil (Otiorhynchus cribricollis) management and monitoring in Pink Lady™ apple orchards of south-west Australia

Louise YatesA, Helen SpaffordA,C and Stewart LearmonthB

A School of Animal Biology, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.

B Department of Agriculture and Food, South West Highway, Manjimup, Western Australia 6258, Australia.

C Corresponding author


Summary

The apple weevil, Otiorhynchus cribricollis Gyllenhal (Coleoptera: Curculionidae), is a pest in apple orchards in south-western Australia. We sought to evaluate the potential for an integrated pest management approach for apple weevils by assessing multiple control tactics and monitoring. Our two aims in this study were to (1) compare the relative effectiveness of insecticides and chickens for weevil management and (2) monitor weevil populations at five properties over a single growing season to evaluate the best time to monitor.

To assess insecticides and chickens as management tools, weevil numbers were monitored under three treatments: management with insecticides, free-range chickens and untreated control. The insecticide treatment resulted in fewer apple weevils than the untreated plots but numbers of weevils were lowest in the chicken treatment. Fruit weight and stem damage were also measured but were not significantly affected by the treatments.

To evaluate the best time to monitor weevils, the number of weevils in apple orchards was evaluated at five properties from October 2004 to April 2005. Two aspects of the weevils’ lifecycle were measured: overall population fluctuations and the variability of numbers between the trunk and the canopy of the apple tree. The number of weevils was relatively low in late spring but rose in early summer. In early January weevil abundance declined and was followed by a small second population peak in February before the population declined to low levels by April. A greater number of weevils were observed in the monitoring bands placed on the trunk of the tree compared to bands placed in the canopy.

Keywords: insect pest, monitoring, biological control, Gallus domesticus, apple weevil, curculio beetle, Otiorhychus cribricollis.

 

Plant Protection Quarterly (2007) 22 (4) 155-159.