Volume 63 Number 16 Date 08/23/2018
BROWN MARMORATED STINK BUG - Adults have been captured on clear sticky panel traps in Dane, Kenosha, Marquette, and Racine County apple orchards this month, signaling the potential for fruit injury prior to harvest. The recent detection of BMSB near Montello is the first confirmed case for Marquette County and a new county record. Late-summer populations are likely increasing in areas of the state where BMSB is established, and it will be important for fruit and vegetable growers to remain alert for stink bug activity through October.
OBLIQUEBANDED LEAFROLLER - Orchardists are reminded to maintain pheromone traps for this insect well into September. Second-generation larvae occasionally cause severe fruit damage late in the growing season and moth counts in late August and September can be a predictor of damage potential of the overwintered larval population next spring.
CODLING MOTH - Moderate to high counts were recorded in a few orchard locations in the past week, confirming that significant codling moth flights are still occurring. Large captures of 16-35 moths per trap were reported from Iowa and Racine counties. Approximately 90% of second-flight adults will have emerged once 1,700 degree days (modified base 50°F) have accumulated from the first biofix, and pheromone trap checks may be discontinued after August 30.
APPLE MAGGOT - Peak emergence of flies occurred about two weeks ago depending upon the area of the state, and activity has generally declined. Apple maggot pressure has been variable but generally low this season, though the external depressions and brown, internal larval tunnels indicative of AM infestation are appearing on apples at some orchard sites where AM flies have been more abundant this season. Growers should continue to monitor AM traps through the first week of September since the flies are still active and could cause problems in late cultivars.
SPOTTED TENTIFORM LEAFMINER - The third and last flight of the season continued this week, with counts ranging from 6-405 moths reported from 21 monitoring locations. Most orchards registered low weekly captures of fewer than 100 moths. Moth activity is expected to subside by mid-September.
-- Krista Hamilton, DATCP Entomologist