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IPM Message for Cranberry Growers: Jul 12, 2019

July 12, 2019

Cranberry fruitworm sprays (Altacor) should be going on. Current recommendations are to spray at 50% out-of-bloom for all varieties except Howes. Please use the traditional cranberry fruitworm timing for Howes, spraying 7-9 days after 50% out-of-bloom.  This is still the best management strategy for this variety.  Your second application goes on once bloom is gone, usually 10-14 days later.

Weevil has been detected in high numbers (25-40) on some sites.  You need to be completely out of bloom, or have your bees removed, in order to spray Actara to manage weevil at this time.  If you have bloom on the bog, you must wait.  Avaunt does NOT work on this summer generation and should not be used.  Exirel, the new diamide insecticide, has some potential to work on weevil but there have been mixed results.  It is very expensive ($70/A) and also CANNOT be used when flowers are still on the bog.  IF it works, it could double as your cranberry fruitworm.

3 reports of a tiny leaf-feeding beetle have come in.  This beetle is tiny, tiny - about 1 mm, about the size of a sesame seed and is a brownish. Sweeps in damaged areas result in a hundred tiny beetles.  The damage is feeding on the tip of the upright and any soft growth including bud, flowers and berries.  It is a chysomelid beetle in the cryptocephalid subfamily but there is little other information.  It is similar to fire beetle but much smaller.

tiny beetle, fire-beetle like

If you are treating Spag with growth regulators (Confirm, Intrepid) or Altacor, treat 3 weeks after moth flight begins; this could be now or very soon. Make at least 1 more application 10-14 days later.  When treating with Delegate, apply 10-14 days after PEAK moth capture (usually around mid-late July).  Lorsban and Orthene are poor choices for Spag management and are not recommended.

Now is the good window to use QuinStar for yellow loosestrife control, if you can use the herbicide as per your handler. 

Dodder can be controlled with concentrated spot applications of Callisto.  It is best to apply the herbicide BEFORE dodder flowers.  Some inland locations have dodder flowering already. Use 1-1.5 oz of Callisto per gal water plus an NIS or COC, also at 1.5 oz per gallon water.  If it’s hot and humid, use an NIS.  If it’s really hot and humid, wait until the weather breaks before applying any herbicide.  Remember you cannot exceed 8 oz Callisto per acre.  If you use 1.5 oz Callisto per gallon water, you can only treat approximately 8,000 sq ft or less than 1/5 of an acre.