Volume 57 Number 16 Date 08/02/2012
APPLE MAGGOT - Emergence of this fruit fly has increased in several apple orchards in the past week. Growers should maintain trapping and control regimens as long as the flies persist and counts exceed established economic thresholds. The high count for the week was 25 adults on a red sphere trap at Gays Mills in Crawford County. Apple maggot activity is likely to continue through early September, or until 2,800 degree days (base 50°F) are reached.
SPOTTED TENTIFORM LEAFMINER - Large flights of 730-900 moths were registered at several sites from Racine to Marathon County during the last reporting period. The third and final flight should peak in the next 1-2 weeks in the central and northern areas and decline to low levels by late August.
CODLING MOTH - Moths are still appearing in very high numbers in pheromone traps. The peak of the second flight has occurred at most locations, but activity has not slowed and additional treatments may be necessary this month. The average count this week was eight moths per trap, with a high count of 43 moths near Oneida in Brown County.
OBLIQUEBANDED LEAFROLLER - It is recommended that apple growers continue to scout for larvae on terminals and any remaining growing points, sites at which fruits are in contact, and in areas where leaves are covering the fruit. Although late-season injury to fruits caused by this insect is usually subtle, large numbers of apples can be infested. Once the larvae have bored into the fruit, no treatments are effective.
--Krista Hamilton, DATCP Entomologist