Integrated Strategies to Slow Ash Mortality in Emerald Ash Borer Outlier Sites. Steven Katovich USDA Forest Service, Forest Health Protection

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1 Integrated Strategies to Slow Ash Mortality in Emerald Ash Borer Outlier Sites Steven Katovich USDA Forest Service, Forest Health Protection

2 SLAM objectives Slow the onset and progression of widespread ash mortality in an EAB outlier site. Reduce the rate at which EAB populations grow or spread or both.

3 SLAM is not an eradication program this means that we should expect local EAB populations to build and spread.but this should occur at a slower pace than what would happen if SLAM tactics were not applied. SLAM is an attempt at buying time, locally and regionally.

4 What is an outlier site?

5 The Over-Riding Theme of a SLAM Strategy Reduce EAB numbers and the growth of EAB populations and thereby slow the build-up and expansion of ash tree mortality

6 SLAM components The initial SLAM strategy was developed in Refinements continue to be made. EAB surveys for distribution and density Ash surveys for distribution and amount Population suppression tools and tactics o Removal of infested trees, insecticide treatments, girdled ash trees (sinks) Regulatory activities Data management and evaluation Outreach and communications

7 Population suppression tools and tactics - Prompt removal of infested trees EAB infested trees can produce ca EAB adults per square ft of bark surface area. A single 20 inch diameter ash tree can produce beetles.

8 Population suppression tools and tactics insecticide treated trees toxic to EAB Newly emerged beetles feed on ash leaves prior to mating and egg laying toxic leaves will kill any EAB adults that feed on them. Place treated ash trees around an EAB infestation so that dispersing beetles encounter toxic trees as they move out of an area. Photo David Cappeart

9 Population suppression tools and tactics girdled ash trees that act as EAB sinks Dispersing female beetles will be attracted to stressed, freshly wounded ash trees where they will lay eggs. This concentrates EAB into trees that can be removed before emergence of the next generation of beetles.

10 SLAM Simulation study Insecticide injections (emamectin benzoate) would have the greatest negative impact on EAB populations (kills both adult beetles feeding on the leaves and larvae in treated trees) Annual injection treatments of 20 % of the local ash trees could have a major impact on EAB population buildup Focusing injections close to the introduction point is beneficial very early in the outbreak cycle But, too much focus on one area may be problematic it can be hard to locate the extent of an EAB population. Systematic placement of injected trees over a larger area may be the best approach

11 SLAM Simulation study Starting insecticide injections in year 2 or 3 vs. year 4 or 5 of an infestation was very beneficial this requires early detection Removal of only infested trees had little impact on the future rate of tree mortality. These were trees that were showing signs of decline (trees with >60% phloem consumed by EAB) SLAM type activities are more likely to work in urban landscapes (easier access and better ash inventory data)

12 SLAM Simulation study Insecticide injections (emamectin benzoate) would have the greatest negative impact on EAB populations Girdling ash trees (sinks) and destroying larvae before emergence significantly reduced spread of EAB Girdled trees are more attractive to egg-laying EAB females placing a large girdled tree or group of girdled trees too far ahead of the leading edge of the population could potentially increase the spread rate of EAB Removal of ash phloem by itself (phloem removal) did reduce EAB populations in the treated area but not outside the treated area, there was evidence for increased spread in this study

13 SLAM Pilot Project Take the simulation results and see if they hold up in real world situations?

14 SLAM Pilot Project Moran and St. Ignace, Michigan Fall 2007 A total of 13 infested trees were identified in Moran by Nov The oldest larval gallery was dated to Another infested tree was later found in St. Ignace, MI, 7 miles south of Moran. These two apparently isolated, young infestations provided an opportunity to implement and evaluate the SLAM strategy

15 SLAM Pilot Project Upper- Peninsula of Michigan Moran & St. Ignace Laurium & Calumet 2008 Laurium Calumet Houghton County Moran St. Ignace Mackinac County

16 SLAM Pilot Project Status October 2012 Field data was collected from , 2012 field data is still being collected (peeling of detection trees) Various treatments were applied in , (insecticide injections, sinks, infested tree removal, bio control releases) The emphasis is shifting from the implementation of various treatments towards evaluation of any impact that treatments have had on spread rates and buildup of EAB populations, and the spread and local intensity of tree mortality

17 Evaluation Compare what happens in the Moran area where few treatments were implemented to the St. Ignace and Houghton sites where treatments were more numerous and extensive Evaluate EAB density data (larval counts taken from peeled detection trees) to population estimates obtained from simulation models. The simulation models were developed based on tree peeling data from other MI sites and supplemented by data coming from Moran Forest health plots evaluate the spread of tree mortality

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25 Spread rate from the Moran infestation has been ca. 1.4 km/yr Spread rate from the St. Ignace infestation has been ca. 0.5 km/yr More treatment activity in St. Ignace Than in the Moran location

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28 SLAM web site

29 Acknowledgements Thanks to the SLAM Working Group John Bedford Michigan Department of Agriculture Bob Heyd and Ron Murray - Michigan DNR Andrew Storer - Michigan Tech University Deborah McCullough and Amos Ziegler - Michigan State University Therese Poland USFS, Northern Research Station Jean Perkins - Hiawatha National Forest