Fruitpiercing moths and fruitspotting bugs: Intractable pests of tree fruits in a reduced-insecticide environment

Abstract

Published and unpublished information on fruitpiercing moths (Eudocima spp.) and fruitspotting bugs (Amblypelta spp.) is presented to highlight the difficulties in managing these insects in Australia, where there is an ongoing emphasis on the reduced use of broad-spectrum insecticides in tree fruit production. These important polyphagous pests of tree crops possess piercing mouthparts which enable them to penetrate the skin or rind of most fruit, the damage resulting in lost crop or unmarketable product. Between them, fruitpiercing moths (FPM) and fruitspotting bugs (FSB) feed on around 40 different cultivated fruits or nuts, and crop losses greater than 50% have been attributed to each on occasions. Control of FPM with insecticides is difficult, and so alternative methods have been sought to combat these pests. Netting trees and bagging fruits can be totally effective, but are not economical options for most crops unless other significant pests (e.g. birds, flying foxes) are controlled too. Light protection systems can reduce damage by 60-70%, while a new baiting system has provided 75-85% protection in citrus trials. FSB have traditionally been controlled with prophylactic applications of endosulfan, but restrictions on the use of this chemical and a greater reliance on crop scouting have resulted in a general reduction in insecticide use. Further rationalisation may occur if it can be shown that fruit loss due to bug damage does not increase that resulting from natural thinning. While some work on biological control of both pests has been undertaken, future research could also focus on sex pheromones, plant attractants and novel insecticidal or repellent compounds.