Dealing with SWD: The Michigan Experience Rufus Isaacs Department of Entomology Michigan State University East Lansing, MI 48824 isaacsr@msu.edu
SWD distribution - U.S. and Michigan? The Boston Globe and Hannah Burrack, NCSU MSU Extension Fruit Team Also found in Mexico, Italy, Germany, UK, Spain, France, etc
Stages of SWD response Denial Anger Despondency Acceptance Solutions
The Michigan SWD timeline 2009 reports of a new damaging pest in CA 2010 - formed SWD Response Team, initiated trapping, detected in September, winter education program. 2011 First full season, first catch 7/5, some blueberry damage. 2012 Workshops, first catch early June, crop infestation, economic loss. 2013 More workshops, first catch late May, intense management, higher production costs but lower crop loss.
SWD Response Team Extension specialists, extension field staff, Dept. of Agriculture, crop commodity leaders, leading growers Essential for communication, especially early Key members of the trapping network Manage the public message Rapid transition of research information to growers Priority setting Economic impact estimation
September 2010
Grower and crop consultant training workshops Workshops to provide pre-season training. Hands-on training Identification Trapping Fruit sampling
Seasonal blueberry pest timing Growth stage pre-bloom bloom mid-season pre-harvest harvest post-harvest Degree days base 50 F from March 1 100 300 400 700 1100 1300 1900 2500 Cutworms Spanworms Leafrollers Gypsy moth Thrips Cherry FW Cranberry FW Plum curculio Aphids BB maggot Japanese beetle Tussock moth BB bud mite S.W.D. Bars show period when scouting and management of the pest is most important. Blue = key pest
80 70 60 50 40 30 20 10 0 7/31 8/7 8/14 8/21 8/28 Average SWD per trap 9/4 9/11 9/18 SWD activity in managed blueberry fields, 2011 Bluecrop Jersey Liberty Elliott Aurora Conventional Minimally Managed Last sprays
Monitoring: phenology of SWD activity First SWD detections: 9-23-10, 7-7-11, 6-8-12, 6-6-13 Weekly SWD reports online Rapid population growth in late Julyearly August. Just after cherry harvest, during later blueberry cultivars and raspberry/blackberry ripening period.
Comparative catch by region and production system NW trapped through Sept 9 WC, SW & SE trapped through Aug 18
Timing of SWD activity in cherry, 2013 Yeast-baited trap Avg. SWD per trapping site 400.0 350.0 300.0 250.0 200.0 150.0 100.0 SW NW SW 1 st catch July 1 NW 1 st catch July 29 50.0 0.0
Comparative catch in 4 cherry production regions Northwest-NW West central WC Avg. SWD per trapping site 350 300 250 200 150 100 50 0 Southeast-SE 318 182 21.3 26.1 NW SW WC SE NW trapped through Sept 9 WC, SW & SE trapped through Aug 18 Southwest-SW
Mean SWD / trap / week Mean SWD / trap / week 8 7 6 5 4 3 2 1 0 12 10 8 6 4 2 0 2011 Influence of adjacent forest habitat Forest Berry Open Space 2012 a a b b P = 0.005 P = 0.001 Forest Berry Open Space b b Average total number of SWD adults reared per ounce 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Conventional Organic Minimally managed 0 15 30 45 60 Distance from field border (m)
Non-crop host plants as hosts for SWD These species were collected from Michigan woods with SWD infestation. Many other plants were negative for SWD. Common name Scientific name Ripe fruit period Honeysuckle Lonicera spp. 7/1 10/7 Common blackberry Rubus sp. 7/8 9/16 Bittersweet nightshade Solanum dulcamara 7/21 10/3 Stiff dogwood Cornus foemina 8/19 10/6 Elderberry Sambucus canadensis 8/15-9/20 American pokeweed Phytolacca americana 8/26 10/7 Silky dogwood Cornus amomum 8/29 10/7 Spicebush Lindera benzoin 9/8 10/7 Autumn olive Elaeagnus umbellata 9/8 10/6
Clear plastic deli cup trap with ten entry holes. Replicated in OR, NC, MI. 4 reps per state, RCBD. Weekly checks for 8 wk. Apple cider vinegar + insert + soap + insert and soap Comparing baits, soap, and inserts, 2012 Yeast+sugar + insert + soap + insert and soap Yeast+sugar: 6.2 ml yeast, 24.6 ml sugar, 150 ml tap water. Soap added at 4 ml per gallon.
Average total SWD per trap 50 45 40 35 30 25 20 15 10 5 0 d ACV, No Soap, No YSI Comparing baits, soap, and inserts, 2012 ANOVA (on log x+1 data) Means separation: Tukey F=104.3, P<0.0001 Aggregated data from OR, MI, NC c ACV, No Soap, YSI c ACV, Soap, No YSI c ACV, Soap, YSI ab Yeast, No Soap, No YSI a Yeast, No Soap, YSI b Yeast, Soap, No YSI ab Yeast, Soap, YSI
Yeast-sugar baited traps catch SWD earlier in 2012 Standard plastic traps baited with apple cider vinegar or a yeast-sugar solution. Yeast mix: 1 Tbsp yeast 4 Tbsp sugar 12 oz water Yeast+sugar: higher proportion of traps positive for SWD. Similar to 2011, despite detecting SWD one month earlier in 2012. Average % of traps catching SWD flies 100 80 60 40 20 0 27-May Yeast+Sugar ACV 3-Jun 10-Jun 17-Jun 24-Jun 1-Jul 8-Jul 15-Jul 22-Jul 29-Jul 5-Aug 12-Aug 19-Aug 26-Aug 2-Sep 9-Sep 16-Sep 23-Sep
Monitoring for SWD Minimum of 3 traps per farm. Best efficiency at 1 trap/5 ac. Locate traps at high risk sites. Problem areas last year Near woods, in shaded area, next to wild host plants Deploy before fruit ripening. Bait with yeast-sugar mix. Check for SWD and change weekly.
Monitoring for SWD Consultants and scouts using yeast-sugar mix as bait. Ease of use is a major issue. Effectiveness of home-made traps Some are quite small, with few holes, not placed in the shade Questions about the value of traps for anything more than first detection. Average D. suzukii adults per trap 40 35 30 25 20 15 10 5 0 Multi-state collaborative trial Michigan data only Correlation to infestation risk?
Relative size of blueberry maggot and SWD larvae BBM SWD
Sampling berries for SWD BBM SWD Avg. SWD per sample 14 12 10 8 6 4 2 Boil Hand Sorting Salt Sugar Salt solution and boil tests were most effective Blueberries infested with SWD Sampled 5 days later with four different methods 0 Boil test: cover with water, boil for 1 minute, strain and wash through coarse mesh. Salt solution: lightly crush berries then cover with solution of 1 cup salt per gallon water.
Sampling fruit for SWD IN FIELD SAMPLING Gather harvestable berries (1 lb) into a ziplock bag. Pour salt solution (1 cup/gallon) over berries. Wait 20 mins, or longer, and count SWD larvae. PROCESSOR SAMPLING Gather berry samples (1 lb, or more). Use salt test (above) or boil test. Record # of SWD larvae per pound sampled.
Other cultural control options Sanitation! Remove soft/infested fruit Remove potential hot-spots outside fields Bug-Vacs? Solarization to kill larvae in infested fruit Bag and seal fruit before disposal Cool fruit to stop fly development (0.6-3.3 o C) Freezing kills SWD
Cultural control approaches Sanitation Wild host removal Interception/exclusion Post-harvest removal
Parasitoids - Willamette Valley Field Surveys: 2012-2013 Sentinel Baits 6 Sites selected for diverse habitat + SWD population Host larvae of SWD, D. melanogaster, no host Fruit and artificial diet media One week intervals May - Oct Application: Develop sampling protocol for future studies Dalton, B. Miller, J. Miller, Tochen, Walton, York
Parasitoids - P. vindemmiae in the field 2012 2013 Photo: V. Walton Dalton, B. Miller, J. Miller, Tochen, Walton, York
Foreign exploration for natural enemies of D. suzuki in its native range ARS BIIR & Italian team in China & Korea, July- August: 3-4 spp. of braconids and 7 figitids collected - 2 species placed in culture at Newark - 1 braconid & 1 figitid from Korea Oregon State Univ. team in Korea, mid-august - 4 species at UC Berkeley (IDs not known)
Larval Parasitoids 6% Photo: Xingeng Wang Photo: Xingeng Wang Asobara sp. (Braconidae) Pupal Parasitoids Ganaspis sp. (Figitidae) <1% 10% 20% Photo: Xingeng Wang Photo: Xingeng Wang Trichopria sp. Pachycrepoideus sp. (Diapriidae) (Pteromalidae) 33% J. Miller, Shearer, B. Miller, Walton, Daane, Wang
Goal now is to conduct quarantine studies Ganaspis spp. emerging from SWD Smaller when emerging from D. m. Non-target studies (is this safe to release?) 1) No-choice tests 2) Choice tests Daane lab How effective on alternate hosts?
Summary: Classical biological control 1) OSU researchers collected in So. Korea and parasitoids reared are currently in the UCB Quarantine; 2) 4-5 parasitoid species were recovered, with all species easily reared on SWD and one species appearing to be a specialist on SWD 3) the quarantine work now is to get USDA APHIS release permits. Daane lab
Harvest and post-harvest logistics Harvest Make contingency plans for scheduling monitoring, spraying, harvest, and irrigation. Shorten harvest intervals to reduce chance of large larvae in berries. Sample berries to determine SWD infestation. Post-harvest Sample berries to determine SWD infestation. Sanitation of waste piles, dropped berries. Cooling from picking-to-plate.
Post-harvest removal
Dreves, Cave, Lee, Bruck- OREGON COLD TREATMENT for POST-HARVEST BLUEBERRIES, Bluecrop
2012-13 Research/Extension, and 2014 plans Studies in grape, raspberry, blueberry, cherry Monitoring and trap improvements Insecticide evaluations in blueberry, raspberry, cherry Resistance monitoring Rainfall effects on crop protection Post-harvest control Sprayer comparisons SWD management guidelines Extension programming - hands-on workshops, etc. SWD website development and maintenance SWD biology, exclusion in raspberry, continued efficacy studies, baseline resistance monitoring, MRLs.
SWD Resources from MSU www.ipm.msu.edu/swd.htm
Questions?