Plum curculio movement into orchards

Greetings, For the last couple of years we have experienced the kind of weather patterns during the apple bloom and post-bloom periods that are conducive to protracted movement of plum curculio into orchards from their overwintering habitat in adjacent woodlands. While many plum curculio may move into orchards more synchronously in years when conditions are warm and dry during the bloom, therefore resulting in good control when effective products are applied at petal fall, in a year like 2016, this pest may need to be targeted with additional sprays after petal fall, especially in orchards where pressure has been high in recent years. The warming pattern forecasted for next week may well result in increased curculio movement. In the northern regions of Virginia, next week will also bring the critical 250DD post-biofix timing for codling moth and in the central and southern regions, codling moth degree days will approach the 550 mark, at which the second half of first brood codling moth is targeted. Consequently, if both species require management at this time, the insecticides that are considered effective against both include, in alphabetical order, Assail, Calypso, Imidan and Imidan + Lannate.  In our Spray Bulletin for Commercial Tree Fruit Growers, we rate Avaunt quite strongly against plum curculio but somewhat less so for codling moth. Other products, such as many of the pyrethroids, are also rated well against both, as are some of the combination products that contain a pyrethroid and another active ingredient, such as Voliam Xpress or Endigo, although as always, we caution against using these broad-spectrum materials too early and/or too often in the post-bloom period, since secondary pest issues may result.

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