Managing Insect Pests of Ripening Grapes

Transcription

1 Managing Insect Pests of Ripening Grapes Keith Mason and Rufus Isaacs Department of Entomology, MSU Great Lakes Fruit and Vegetable Expo December 5, 2017

2 Outline Background and biology of key harvest pests Interactions between harvest time pests Trapping for yellowjackets and hornets Efficacy of short PHI insecticides Border sprays to control late season pests Future plans

3 Background Insects causing problems at harvest Wasps Vinegar flies (fruit flies) including SWD Brown marmorated stink bug (BMSB) Bees Ants Multicolored Asian ladybeetles

4 Interactions between pests TNRC Aurore Do stink bugs or SWD increase risk of other pests and diseases? Bagged grape clusters then added SWD and BMSB for 7 days Collected clusters 7, 14, 21 days after removing bags Measured insect damage and rated disease Held clusters in rearing chambers to assess infestation Bagging Treatments 1. Sealed control 2. Open control 3. 3 BMSB mated SWD females 5. 3 BMSB + 10 SWD Replicated 6 times

5 Trial at Trevor Nichols Research Center cv Aurore

6 Exposure to SWD or BMSB doesn t increase infestation by other Drosophila Emerging flies per cluster 7d after exposure Sealed Open SWD BMSB BMSB + SWD 0 Other Drosophila SWD

7 SWD (but not BMSB) increases sour rot infections Sour rot infected berries per cluster Infection 7 days after exposure Sealed Open SWD BMSB BMSB + SWD Treatment

8 Wasp trapping studies Compared baits and traps for mass trapping Six vineyards in NW and seven in SW Michigan Traps out in early June to capture queens Traps used later to draw wasps away 20,000 wasps caught, sorted and identified 10 species collected Eastern yellowjacket was the most common

9 Wasp trapping studies bugguide.net Northeastern yellowjacket Photo: R. Isaacs Eastern yellowjacket Photo: K. Mason German yellowjacket Photo: K. Mason European paper wasp Bald faced hornet bugguide.net bugguide.net Southern yellowjacket

10 Wasp trapping bait comparison Early season trapping was not successful Switched to wider range of baits Apples + apple juice AgriSense bait Vinegar, sugar, banana peel mixture Beef Chicken Fish Homemade 2 liter bottle trap Traps out mid August to mid September

11 Apples and AgriSense bait most attractive in SW 50 All wasps southwest 40 Wasps per trap Apple Agrisense Bait Beef Chicken Fish Vinegar sugar banana mix

12 Trap comparison In SW, compared 3 trap types using apples and AgriSense bait to the Rescue bag trap Compared eastern and western Rescue bag traps In NW, compared Rescue bag traps to Agrisense bait Mid September through harvest in early November 2 liter soda bottle Bucket trap Victor Jar trap Rescue bag traps eastern and western

13 AgriSense bait worked well Average wasps per trap All yellowjackets southwest apple Agrisense bait 0 Bottle Bucket Jar Rescue bag trap

14 Comparison of Rescue bag traps in SW Eastern bait most attractive for eastern yellowjacket, German yellowjacket, and downy yellowjacket All yellowjackets Eastern yellowjacket methyl 1 butanol Heptyl butyrate Wasps per trap Wasps per trap Rescue trap 1 Rescue trap (eastern) (western) 0 Rescue Eastern trap yellowjacket Rescue trap (eastern) (western)

15 Comparison of Rescue bag traps in NW Agrisense bait caught more yellowjackets than either Rescue trap All yellowjackets Eastern yellowjacket Wasps per trap Wasps per trap Rescue eastern Rescue western Agrisense bait 0 Rescue eastern Rescue western Agrisense bait

16 Wasp trapping summary Agrisense liquid is the most attractive bait for catching multiple species The Victor Jar trap caught the most wasps Rescue bags were effective at catching yellowjackets, but be sure to get the eastern version

17 Short pre harvest interval insecticides (PHI) for grapes Remember the label is the law!

18 Insecticide efficacy TNRC plot trials Trials in Foch and Concord Insecticides applied between veraison and harvest (4 applications) Treatments Untreated Mustang Maxx (4 oz) Leverage (3.2 oz) Venom (3 oz) Belay (4 oz) Pyganic (32 oz) Delegate (5 oz) + Mustang Maxx (4 oz) Assessed weekly, and clusters collected at harvest

19 Assessment at harvest Eggs and larvae in two clusters Foch Untreated Venom Pyganic Belay Mustang Maxx Leverage Concord Untreated Pyganic Belay Venom Leverage Delegate + Mustang Maxx Mustang Maxx

20 Border spray approach On farm trials Untreated (3-5 rows) Woods Two wine, two juice grape vineyard pairs Border rows treated every 7 10 days, veraison to harvest Insecticide program 1. Sevin XLR (64 oz) or Delegate (5 oz) 7 day PHI 2. Malathion (30 oz) 3 day PHI 3. Venom (3 oz) 1 day PHI 4. Mustang Maxx (4 oz) 1 day PHI Similar area left untreated for comparison Assessed weekly, and clusters collected at harvest Treated border (3-5 rows)

21 Minimal reduction of flies Emerging flies per cluster Juice Untreated Border Untreated Interior Treated Border Treated Interior Emerging flies per cluster Wine Untreated Border Untreated Interior Treated Border Treated Interior 0 28 Sep Other Drosophila SWD 0 11 Sep Other Drosophila SWD

22 Summary and future directions Neither SWD or BMSB increased vinegar fly infestation. SWD increased sour rot infection, but BMSB did not have the same effect. Study repeated in Many more native vinegar flies than SWD emerged from clusters. Similar species of wasps were found across Michigan vineyards, eastern yellowjackets most common. AgriSense liquid bait was the best attractant across all the abundant species and at all sites. Victor Jar traps performed best.

23 Summary and future directions Rescue bags caught similar numbers to Agrisense baits, but be sure to get the eastern version. Wasp trapping in 2018 will include economic analysis of different traps. Focus on whether traps are reducing the number of wasps, damage, and stings in vineyards. Some short PHI insecticides were effective at reducing fruit fly infestation at harvest. On farm work will be repeated in 2018.

24 Pest Alert!! We need your help. If you see spotted lantern fly report it to your county extension agent. Take a pest alert flyer from the table in the back.

25 Thanks! Grower cooperators The Isaacs lab and the TNRC farm crew