Fruit Fly ITTC member Dr Maurizio Benelli explains that Sterile Insect Technique (SIT), a benign pest control strategy, is currently undergoing a substantial renewal for controlling the Queensland fruit fly (Q-fly), a major horticultural pest in Australia. Production and delivery of high-quality flies are fundamental to effective SIT. While efforts are commonly made to improve production at a factory level (both quantity and quality), the methods and conditions during post-production operations also need to be tuned to minimize reductions in fly quality. Hypoxia, irradiation and vibration are important stressors that are experienced by pupae during production, packing and transportation.
To study the mechanism behind stress resistance during SIT operations and the consequences on fly quality, Dr Benelli conducted two laboratory experiments to develop guidelines that minimise quality reductions for SIT programs and improving the effectiveness of this pest control strategy in Australia. During the first experiment, Q-fly pupae of different ages (3, 6 or 9-day old) were exposed to vibrations for 5, 30, 60 and 300 s. Flight ability tests revealed that 6- and 9-day-old pupae were the most sensitive to vibration, with a significant reduction in emergence and percentage of fliers. During the second experiment, the effect of hypoxia, irradiation and vibration, in isolation or in combination, was evaluated on 9-day-old pupae. Irradiation and vibration exhibited a multiplicative negative effect on flight ability parameters. It is recommended not to subject pupae to intense or extensive vibration during the late pupal stage and to avoid prolonged periods of hypoxia.
Dr Benelli and his coauthors have published their findings in the Journal of Pest Science.
"Reduced quality of sterile Queensland fruit fly following post-production stress from hypoxia, irradiation and vibration"
M. Benelli, B. Mainali, P. W. Taylor & P. Rempoulakis
Photo: Dr Maurizio Benelli conducting fruit fly research at Applied BioSciences, Macquarie University.