The effect of cold storage of mass-reared codling moths (Lepidoptera: Tortricidae) on subsequent flight capacity
Citation
Matveev, E., Kwon, J.J., Judd, G.J.R., Evenden, M.L. (2017). The effect of cold storage of mass-reared codling moths (Lepidoptera: Tortricidae) on subsequent flight capacity. The Canadian Entomologist, [online] 149(3), 391-398. http://dx.doi.org/10.4039/tce.2017.1
Plain language summary
Codling moth is the key fruit-feeding caterpillar pest of apples worldwide. In British Columbia, codling moth is controlled using a technique called sterile insect release. During summer an insect rearing facility in Osoyoos produces millions of sterile moths and releases them into apple orchards where they mate with wild moths. Sterile moths provide control because mated wild females produce sterile eggs that do not hatch. During the process of producing moths for release they are stored in cold for varying lengths of time and this cold storage may damage the moths ability to fly and disperse into orchards. To understand these effects we measured the flight capacity of moths in the laboratory using a computer-linked flight mill, the insect equivalent of a tread mill, and measured their potential flight distances after being stored in cold. We discovered that the current cold-storage procedure used by the SIR Program does not negatively influence the moths subsequent flight capacity.
Abstract
Flight capacity of codling moths, Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae), was measured with computer-linked flight mills following exposure to one of two temperature regimes. Codling moth adults were held for 24 hours before flight under either chilled (2 °C) or unchilled (24 °C) conditions. The chilling treatment emulated conditions that codling moths are exposed to pre-release in the Okanagan Sterile Insect Release (SIR) Programme. Moths were assayed on flight mills for eight hours to obtain a measure of flight capacity based on total flight distance. Energy use was assessed by weight loss during flight and post-flight body lipid content compared with similarly treated moths that did not fly. Flight distance did not vary with pre-flight temperature treatment, however moth pre-flight weight influenced flight capacity; heavier moths flew further. Moths chilled before the bioassay used less energy based on reduced weight loss and higher lipid content post bioassay as compared with unchilled moths. The current cold storage procedure used in the SIR Programme does not negatively influence subsequent flight capacity and reduces energy use during flight. Codling moths can fly on average between 7-10km in an eight-hour flight mill bioassay and lipids, at least in part, are used to fuel flight.