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Fruits
Volume 59 Number 3 Date 05/15/2014 THRIPS - According to Orchard IPM Specialist John Aue, the severe thrips infestation noted in a Sauk County apple orchard on May 9 suggests a major migration occurred late last week and that this pest warrants close attention this spring. Chemical intervention at petal fall or first cover may be required for orchards experiencing heavy populations. John advises growers to check buds on several different varieties in multiple locations, including the orchard perimeter, for thrips activity. A count of three or more thrips per fruit bud can cause abnormal leaf formation, leaf tatter, flower injury and reduced fruit set and is considered an economic population. Materials available for thrips control are spinosad (Entrust) for organic growers and spinetoram for conventional growers (Delegate or Radiant [for strawberries]). REDBANDED LEAFROLLER - The first flight has accelerated and egg deposition is well under way. Small larvae should begin emerging in the next two weeks. A recommended sampling method for this insect is to start monitoring for early-instar larvae on foliage and watersprouts 10-12 days after the first moth is registered. Late-instar larvae and pupae can be found by searching for folded leaves. An important distinguishing feature of the RBLR larva is its uniform coloration (both the body and head are yellowish-green). Other leafrollers have black or dark heads. SPOTTED TENTIFORM LEAFMINER - Peak emergence of first-brood moths is approaching across much of the state. The apple orchards near Deerfield in Dane County and Oneida in Brown County reported high counts of 800-825 moths per trap from May 7-14. Elsewhere counts ranged from 1-546 per trap. The number of moths captured during the period defined as a "peak flight" varies by orchard but is generally in the range of 800-1,200 per trap per week. ORIENTAL FRUIT MOTH - The first of three moth flights that occur annually in Wisconsin has begun across the south. Apple growers concerned about this insect should place pheromone traps by early next week. -- Krista Hamilton, DATCP Entomologist 
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