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Fruits
Volume 59 Number 13 Date 07/31/2014 APPLE MAGGOT - Captures on red spheres and yellow sticky traps increased slightly this week, with reports of flies from eight of 28 monitoring locations. One half of the adult population is expected to appear by 1,600 heat units (base 50°F), which would place 50% emergence between July 27-August 11 in the southern half of the state and 1-2 weeks later in areas north of Green Bay. The highest weekly count as of July 30 was 38 flies on a red sphere at Gays Mills in Crawford County. Maintenance of traps will be important as emergence continues and oviposition on apples increases in August. SPOTTED TENTIFORM LEAFMINER - The third flight of moths is beginnng in southern orchards where 1,479-1,523 degree days (base 50°F) were surpassed as of July 30. The economic threshold for the third and final generation increases to five mines per leaf. CODLING MOTH - Most apple orchards are beyond the summer biofix and treatments for second generation larvae have started. Pheromone trap counts should be used at this time to assess efficacy of first generation control or a weakness in a codling moth management program. According to John Aue of Threshold IPM Services, orchards with counts that remain uniform from trap to trap during the second flight likely have a local, in-orchard population. If using organophosphates (Imidan) for control of the summer generation, growers should replace trap liners before an application to monitor the effectiveness of the material. Moth counts that do not decline to zero or near-zero following treatment suggest resistance issues have developed and use of organophosphate material should be discontinued. OBLIQUEBANDED LEAFROLLER - Larvae are in the late instar stages in the southern and western counties. Beyond the first and second instars, this leafroller becomes increasingly difficult to control and much of its feeding damage has already occurred. Emergence of the summer brood of moths is anticipated by mid-August. -- Krista Hamilton, DATCP Entomologist 
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