Pest Management Science (2012) 68, 883-888

Leonardo C. Magalhaes, Jaap B. Van Kretschmar, Vonny M. Barlow, R. Michael Roe and James F. Walgenbach (2012)
Development of a rapid resistance monitoring bioassay for codling moth larvae
Pest Management Science 68 (6), 883-888
Abstract: BACKGROUND: The codling moth, Cydia pomonella (L.), is one of the most important pests of apple worldwide. Use of insecticides for management of this insect has been extensive and has resulted in resistance development. There are a number of different bioassay methods to monitor for codling moth resistance; however, many are not applicable to new insecticides and most are time consuming. A novel 16-well plasticware bioassay plate containing lyophilized diet was developed for rapid resistance monitoring of codling moth.
RESULTS: The contact insecticides acetamiprid and azinphosmethyl were significantly more toxic to neonates than to fourth instars. However, there was no significant difference in LC₅₀ values between neonates and fourth instars to the ingestion insecticides chlorantraniliprole, methoxyfenozide, novaluron and spinetoram. Field colonies of codling moth were significantly more resistant to methoxyfenozide than susceptible populations. A diagnostic dose of 20 µg mL⁻¹ (LC₉₉) was established to monitor for codling moth resistance to methoxyfenozide.
CONCLUSIONS: The results presented here demonstrate that a novel and rapid bioassay can be used to monitor for codling moth resistance to methoxyfenozide. The bioassay method is relevant to both ingestion and contact insecticides, but a single diagnostic dose, regardless of larval age, is only relevant to ingestion insecticides. Age-dependent diagnostic doses are likely necessary for contact insecticides.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): James F. Walgenbach, R. Michael Roe

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Cydia pomonella