|Authors: ||D. Cormier, G. Chouinard, F. Vanoosthuyse, F. Pelletier, S. Bellerose, G. Bourgeois, D. Plouffe, R. Joannin|
|Keywords: ||Malus × domestica, Cydia pomonella, insect phenology, predictive model, insecticide|
Codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae), is a key pest of many fruits and nuts throughout the world.
Apple growers mostly rely on annual sprays of insecticides to prevent economic damage caused by larvae tunnelling the fruit.
Novel insecticides (insect growth regulators and inhibitors) and pesticide-free control methods (mating disruption and biological control) are used, more and more frequently, as replacements of broad-spectrum insecticides to control codling moth.
Timing is critical for these newer tools, and thus, an excellent knowledge of the insect biology is required.
A phenology model, included in CIPRA (Computer Centre for Agricultural Pest Forecasting) software, has been recently modified to describe and predict adult flight, egg laying and egg hatch, in order to help growers synchronize treatments with critical stages of codling moth development.
In this project, we observed adult and larval development of two populations of codling moth in insecticide-free orchard plots, located in two different regions of Quebec.
Weekly sampling and hourly weather data were used to back-calculate hatching dates for each sampled larvae.
In most cases, the model accurately predicted adult flight from trap catches (R2>0.76), and egg hatch (R2>0.94). Complete validation of this model in different regions and orchards of Quebec, which is planned in the upcoming years, is necessary before apple growers can use it as a forecasting tool.
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