Submitted to: Bulletin of Entomological Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2008
Publication Date: 12/9/2008
Citation: Reyes, M., Franck, P., Olivares, J., Margaritopoulos, J., Knight, A.L., Sauphanor, B. 2008. Worldwide Variability of Insecticide Resistance Mechanisms in the Codling Moth. Bulletin of Entomological Research. p 1-11, Dec 9 online early publication. Interpretive Summary: Codling moth is the major worldwide pest of apple, pear, and walnuts and some populations of this pest have developed resistance to a wide variety of insecticide types. Researchers from France, Greece and the United States collaborated to examine the occurrence of several previously identified mechanisms of resistance in codling moth that involve either altered levels of detoxifying enzymes or variants of target proteins. Twenty eight populations from 11 countries were assayed. Significant differences were found for all potential mechanisms among populations and when compared to a laboratory strain of codling moth. This variability was correlated with the recent insecticide history of orchards where moths were collected and exhibited some interesting geographic patterns. Significantly, there was a strong positive correlation in the activity levels of several major classes of detoxifying enzymes suggesting that some codling moth populations may be tolerant to a variety of insecticide classes. Documenting the types and incidence of insecticide resistance mechanisms in codling moth should allow pest managers to develop new strategies to minimize further selection pressure.
Technical Abstract: Known resistance mechanisms including the action of detoxifying enzymes and insensitive variants of target proteins were examined in individual male and female moths from 29 populations of codling moth, Cydia pomonella L collected in 11 countries in Africa, Europe, North America and the Australian continent. Populations were collected from orchards with recent histories of variable insecticide use, as well as from unsprayed sites. The response of an unselected French laboratory strain (Sv) was used as a reference. GST activity levels were significantly higher from the Sv strain in all but one of the 15 non-European populations tested from North and South America, New Zealand, and South Africa. Conversely only six out of the 14 European populations had significantly higher GST levels. MFO activity levels ranged nearly 500-fold among populations and the activities of 10 populations were significantly higher than the Sv stain and four population’s activities were significantly lower. All but seven populations had EST activities significantly different from the Sv strain with all but one of these populations having lower EST activity. Across all populations a significant positive correlation was found for EST activity with both MFO and GST activities and between GST and MFO activity. The frequencies of kdr mutation differed significantly from Sv strain in 10 populations, including all of the populations from France and Argentina. The AchE mutation was detected in only one population from Spain.