SWD in strawberries, blueberries and raspberries

Transcription

1 SWD in strawberries, blueberries and raspberries Gemma Calabria et al Carlos García-Salazar, Rufus Isaacs, Steve Van Timmeren, and Anamaría Gómez-Rodas MSU Department of Entomology MSU Extension Agriculture and Agribusiness Institute

2 Problems hampering SWD control Control strategy directed to adult control. Selection of insecticides with limited effect on life stages inside the fruit. Limited number of insecticides available for the SWD in blueberries, raspberries and strawberries. Limited knowledge of the behavior of the pesticide in the habitat of the insect. Organophosphate, Pyrethroids, Neonicotinoids, etc. Insecticide delivery system and deposition of the product in the insect habitat.

3 Problems hampering SWD control.. Limited understanding of how to adjust insecticide applications to pest behavior and current weather conditions has lead growers to take MSUE recommendations as prescriptions rather than adjustable and more dynamic (changing) recommendations.

4 A systems approach for Managing SWD The purpose of the spray application is to put the pest in contact with the pesticide (García et al. 2011)

5 A Systems Approach to SWD Management Pest Biology and Behavior. Under a Systems Approach growers and IPM practitioners need to understand the biology and behavior of the pest. In the case of the spotted wing Drosophila (SWD) there was no data available until Critical Points of the SWD Life Cycle. Knowing its biology and behavior is not enough. For a successful control, growers need to identify critical points in its life cycle where control actions should be applied to optimize the effectiveness of an insecticide. Pesticide: Physical and Chemical characteristics. Under a Systems Approach one of the most important aspects of pest control is to understand how insecticides behave once they leave the sprayer. Their behavior depends on their chemical characteristics, their toxicological group, current weather and target crop conditions.

6 A Systems Approach cont... Host Plant Structure and Pest Habitat. Plant structure and type of canopy affect the performance of pest management in berries. Affect penetration and deposition of insecticides into the habitat of the pest (Pruning vs. Not Pruning). Also, affect the temperature and relative humidity (rh) in the habitat of the insect; where in the host plant the insect spends the most critical stages of its life cycle. This also helps direct the insecticide s application. Spray Systems and Pesticide Deposition. Different spray systems produce different types of depositions on the plant. Depending on the range of droplets produced by the sprayer the insecticide will reach the insect or its habitat affecting the quality of pest control.

7 A Systems Approach..continuation Biological Monitoring. SWD s management under a Systems Approach requires: Current information on the conditions of the pest at target site. Presence of Natural Enemies and other pests that may influence the success of our SWD control. Also provides information on the success of our IPM actions. Environmental Monitoring. Under a Systems Approach the environment is the driving force behind the entire IPM program. Current & forecasted weather conditions at the target site affect all of the above parameters, including pest biology and insecticide behavior used for SWD management.

8 Biology and Behavior of SWD Reproduction strategy; r Type High reproduction potential > 300 eggs/female. Multiple generations in a short period of time. Behavior: Highly mobile in the adult stage; most of its biological cycle spent inside the fruit protected from insecticide applications. Eggs and larvae near the surface of the fruit breathing through modified breathing tubes. Resistance to Insecticides: High potential for developing resistance to insecticides, specially to Pyrethroid insecticides.

9 Females oviposit eggs under the fruit s skin Isaacs et al., MSU Extension 2012

10 SWD ovipositor and eggs Serrated Ovipositor Fresh egg showing breathing tubes Recently laid eggs on cherries. Notice the white breathing tubes protruding out of the oviposition scare. Pictures by E. H. Beers, Timothy J. Smith, and Doug Walsh.

11 Examples of breathing tubes of SWD eggs Eggs laid in blueberries (left) and cherries (bottom right) Pictures by E. H. Beers, Timothy J. Smith, and Doug Walsh. pn=165

12 Larva: feeds and grows superficially in the fruit Notice breathing tubes and lungs Isaacs et al., MSU Extension 2012

13 SWD Life Cycle Optimal development at degrees Fahrenheit, about 12 day generation time. Adult flies live for 3-6 weeks, and females can lay over 300 eggs. Limited by high heat in summer and by winter cold. Female fly lays eggs into ripening fruit. WSU, Whatcomb County Unlike blueberry maggot, no delay before egg laying.

14 Biological Monitoring Spotted wing Drosophila - male Spotted wing Drosophila - female

15 Blueberries with a hole and a depressed area may indicate infestation Oviposition scar Isaacs et al., MSU Extension 2012

16 SWD damage on Strawberries SWD females lay their eggs under the skin after cutting a slit in the skin of intact ripening fruit. Larvae feed on the flesh of the fruit, causing soft spots on the surface and wrinkling the skin. The fruit will subsequently collapse, scarring of the tissue appears and mold increases. Tanigoshi, et al Insecticide Management of Spotted Wing Drosophila, Drosophila suzukii (Matsumura) In Pacific Northwest Small Fruits. IOBC Budapest, Hungary 2010.

17 SWD damage on Strawberries..continuation Strawberries deteriorate quickly and mold may appear 3 days after egg laying. Figure 1. Damage 3 days after egg laying. Figure 2. Damage 5 days after egg laying. The fruit will subsequently collapse, scarring of the tissue will occur and mold will increase. Photo: Parent, Whitney, Lee; USDA-ARS, Corvallis

18 SWD Fruit infestation in Strawberries Figure 1 - SWD egg (pale form) on strawberry, indicated by yellow arrow. The two yellow objects are achenes ( seeds indicated by black arrows). Figure 2 - SWD Larva on Raspberry-whitish, indicated by arrow. Photos: Phil Pellitteri, UW-Madison Insect Diagnostic Lab

19 SWD damage in raspberries The same berries are shown below after inspection for SWD infestation Removing the peduncle it shows SWD larvae feeding inside the receptacle; the juice stains the cone.

20 SWD in Raspberries These pictures show SWD larvae emerging from infested fruit after being submerged in water with salt

21 Monitoring of adult SWD 1. For earliest detection yeast-sugar mix bait. 2. For easiest use commercial lure (Trece or Scentry). 3. Place traps at field edges, check weekly. 4. Risk is greatest adjacent to woods. 5. Know what you re looking for!! Use MSU Guide to identifying SWD Pictures by E. H. Beers, Timothy J. Smith, and Doug Walsh. WSU. Rufus Isaacs, MSU Extension.

22 SWD monitoring with synthetic lures Plastic container with ten 3/8 inch diameter holes. Hang in shade near fruit. Bait the trap and change the lure once a month. Two options.. 1. With sticky trap: check trap and liquid. or 2. No trap and check insects sifted from liquid (add soap). Pictures by C. Garcia-Salazar, MSU Extension

23 Avg. no. of D. suzukii per trap SWD on sticky insert and in liquid bait of a yeast trap Insert Liquid Checking yeast traps is time consuming and messy. More SWD caught earlier on the insert than in liquid. Checking inserts only would reduce trap assessment time

24 Number of times positive for SWD Number of traps to detect SWD early ACV-baited traps spread across large (50 acre) farms Monitored weekly Analysis of first catch One trap per 5-10 acres Trap Average 6 Traps Average 13 Traps Average 8/26/2011 9/7/2011 9/13/2011 9/21/2011 9/28/ /3/2011 No Detection

25 Environmental Monitoring The weather The weather effect on insect phenology and reproduction potential. We expected Michigan s harsh winter would kill the population and would take care of the problem. Temperatures suitable for optimum reproduction. Relative humidity affects SWD survival and reproduction. Effect on insecticide behavior. Summer heat inactivates main insecticide tools. Summer rains affect insecticide persistence on crop.

26 Percentage of surviving population Effect of Relative Humidity (rh) on survival Tochen et al Humidity affects populations of Drosophila suzukii (Diptera: Drosophilidae) in blueberry.

27 Avg. eggs laid per day Effect of Relative Humidity (rh) on egg laying Tochen et al Humidity affects populations of Drosophila suzukii (Diptera: Drosophilidae) in blueberry.

28 Effect of plant structure and canopy Bush height Canopy structure

29 Canopy and water management: Prune plants to maintain an open canopy. Reduce relative humidity (rh) to make plantings less attractive to SWD and to improve spray coverage. Leaking trickle irrigation lines should be repaired, and overhead irrigation should be minimized. Allow the ground and mulch surface to dry before irrigating.

30 Spray Deposition in Blueberry Fields This slide shows 3 different types of spraying equipment for blueberries, and the spray deposition patterns. Upper left: Cannon sprayer. Upper right: airblast sprayer. Lower left: fixed-wing plane application.

31 Factors Influencing Pesticide Behavior (Image by Marlene Cameron) Pesticide behavior means the manner in which the insecticide acts once it is released onto the crop as a result of the prevailing weather conditions.

32 Environmental degradation of Mustang Max Cypermethrin quickly dissipated, with 29 43% degradation occurring within the first 2 days after the pesticide application. The half-lives for cypermethrin: days Pest Manag Sci 2009; 65:

33 Percent control Percent control Insecticide comparison effect of rain Bushes were protected from rain or had 0.81 inches of rain 24 hours after application. Protected from all other rainfall over 7 days DAT 5 DAT 7 DAT No Rain 3 DAT 5 DAT 7 DAT Rain Isaacs, et al. 2012

34 Pest habitat and behavior The purpose of the application is to put the pesticide in contact with the pest. Placement of pesticide in the habitat: Use the maximum volume of water; 40 galons per acre. Use fine to medium spray; droplet size microns ( 20 to 40 droplets per square centimeter). Taking advantage of pest behavior: Eggs and larvae need to breath fresh air; egg breathing tubes are exposed. Larvae remain feeding under the fruit skin in the outer flesh.

35 Ratings of insecticides for key blueberry pests Insecticide Class REI (h) PHI (d) CBFW Aphids JB BBM SWD Imidan Organophos **** ** **** **** **** Malathion Organophos ** ** ** *** *** Lannate Carbamate 48 3 ** *** ** ** **** Asana Pyrethroid **** ** *** *** **** Brigade Pyrethroid **** ** *** *** **** Mustang Max Pyrethroid 12 1 **** ** *** *** **** Danitol Pyrethroid 24 3 **** ** *** *** **** Assail RR Neonic *** **** ** **** *** Delegate RR Spinosyns 4 3 *** - - ** **** Entrust Spinosyns 4 3 ** - - ** *** Pyganic Pyrethrum 12 0 * * * * ** Evergreen Pyrethrum 12 0 * * ** ** ** RR = reduced risk, = organic Prepared by R. Isaacs, J. Wise, K. Mason and D. Trinka 2012

36 Insecticides against SWD in caneberries

37 Take-home messages: Maintain your current IPM program but make the necessary modifications to incorporate the SWD management. For early warning of SWD: One trap per 5-10 acres, monitor for SWD from just before first ripening. Yeast traps with yellow sticky card for easy adult ID. Trap in woods for early warning. Choose effective insecticides for SWD (Coverage! Rotation!) Broad spectrum: Lannate, Malathion, Imidan, Brigade, Mustang Max, Hero (Brigade+Mustang Max). Reduced-risk: Delegate/Radiant. Organic: Entrust, Pyganic. Sample fruit using salt solution, in-field, before and after insecticide applications, and at processors. Understand the labels (PHIs, REIs, season limits) and residual activity.

38 SWD Resources from MSU

39 What to do to learn & understand the Systems Approach to SWD Management ATTEND online and face to face trainings that will be offered in Traverse City during 2017 (dates to be announced). For more information contact: Dr. Erwin 'Duke' Elsner MSUE Small Fruit / Consumer Horticulture Educator 520 W. Front Street, Suite A, Traverse City, MI Phone: fax: elsner@msu.edu