This past season I had continued re-infestation of potato leafhopper in young unbudded apple rootstock nursery. Calypso provided control, but only until the next population floated in on air currents, presumably from somewhere far south of here (Connecticut). My question is: Are these migrant populations subject to resistance development in the same way that local resident insect populations are? Evidently they are not resistant when they arrive, but to remain within label limits of product per season, other neonicotinoid products might be used to provide continued control. Is anyone aware of resistance having developed in this pest to neonicotinoids or other pesticides where the pest does not survive to pass on its resistance to the next generation? Does potato leafhopper migrate within, say, New England states, or within other Northern apple-growing regions during a growing season? If so, resistance might become a problem regardless of the pest's overwintering ability.
David Kollas Kollas Orchard, CT _______________________________________________ apple-crop mailing list apple-crop@virtualorchard.net http://virtualorchard.net/mailman/listinfo/apple-crop