Volume 61 Number 19 Date 12/08/2016
BROWN MARMORATED STINK BUG - DATCP, the UW-Madison, and the IPM Institute carried out the state's first collaborative BMSB monitoring program in 2016. The program consisted of 51 pheromone traps distributed in 12 counties. Juvenile stink bugs were observed in the Allen Centennial Garden on the UW-Madison campus on July 15 and three nymphs were later collected there in a trap on July 27, marking the first time BMSB had been trapped in Wisconsin. BMSB captures were documented at six sites in Dane County and one in Rock County this season. The positive sites included urban areas, apple orchards and pumpkin plantings. As of late November, the total number of BMSB specimens collected was 185, with a high cumulative count of 80 stink bugs in an orchard near Verona. Peak activity and trap counts occurred from October 5-19. All Wisconsin apple growers are urged to plan for BMSB scouting as part of their IPM programs for 2017.
APPLE MAGGOT - Counts were variable but mostly light this season. The first flies of 2016 emerged during the week of June 30-July 6 in Fond du Lac and Sheboygan counties. Numbers remained low until mid-August when captures peaked at 20 flies per trap per week. The highest weekly counts were registered in orchards with fruits damaged during hailstorms. Minor fruit damage occurred in a few locations by early September, but serious damage was not reported.
CODLING MOTH - Emergence of the first spring moths began near Rochester in Racine County on May 18. Most monitoring locations recorded the first biofix from May 21-25. The spring flight peaked in the southern half of the state by June 15, although counts remained high at many sites for 2-3 more weeks. Signs of larval infestation were evident by late June.
Summer moths appeared in mid-July and counts peaked before the end of the month. A resurgence flight (20 or more moths per trap) was noted in Brown, Grant, Iowa, Kenosha and Racine counties from August 4-11. Heavy flights continued in a few eastern and northern Wisconsin orchards until early September and additional late-season spot treatments were required in orchard blocks where codling moths remained abundant.
JAPANESE BEETLE - Reports indicated higher-than-normal populations this year. Neem oil applications made before most of the beetles began emerging in July provided temporary repellent activity, but conventional contact pyrethroid insecticides were also required for control. Beetles remained abundant for 10 weeks. The largest numbers appeared during the latter half of July into August and a decline was not noted until September.
-- Krista Hamilton, DATCP Entomologist
BLUEBERRY MAGGOT - Survey work conducted by DATCP resulted in the first confirmed detection of adult flies in Adams and Sauk counties on August 2, and a new state record. The specimens were captured on yellow sticky board traps set in wild blueberries. Reported from Maine and New Hampshire in 1914, this native fruit fly is an important pest of commercial blueberry crops in the eastern and southern U.S. and eastern Canada. Its larvae, or maggots, develop entirely within the blueberry fruit, causing berries to become soft, watery and unmarketable. This detection could have economic implications for exporters of blueberry plants and fruits to Canada where blueberry maggot is a regulated pest and strict import controls are enforced. Additional survey traps were set in Jackson, Juneau, Marinette, Monroe and Oconto counties, with negative results.
-- Tracy Schilder, DATCP Plant Pest & Disease Specialist
APIARY INSPECTION - Apiary Program specialists visited 164 beekeepers this year, opening 2,208 hives for inspection. Based on these voluntary inspections, winter mortality was down from 57% in 2014-2015 to 48% in 2015-2016, though reported losses are still very high. Varroa mites were detected in 68% of hives sampled, compared with 71% positive last season. Other pests and diseases found include American foul brood in 1.2% of hives, chalkbrood in 2.8% of hives, European foul brood in 0.3%, deformed wing virus in 7.3%, sacbrood in 0.4%, and small hive beetle in 7.5% of hives. Inspectors issued 55 apiary inspection certificates for 28,232 migratory hives, primarily destined for California, Florida and Texas to be used for pollination services.
-- Liz Meils, DATCP Nursery Inspector