Emerald Ash Borer: Background & Overview of the Green Menace NATHAN W. SIEGERT, PH.D. FOREST ENTOMOLOGIST

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1 Emerald Ash Borer: Background & Overview of the Green Menace NATHAN W. SIEGERT, PH.D. FOREST ENTOMOLOGIST US FOREST SERVICE NORTHEASTERN AREA STATE & PRIVATE FORESTRY FOREST HEALTH PROTECTION

2 First Detected in Detroit EAB was first detected in the US in Detroit, MI in Many thousands of ash trees were already dying. The Port of Detroit receives significant international shipping.

3 EAB is the most destructive forest insect in North America EAB has killed millions of ash trees in North America. Transported to new areas in infested firewood, timber and nursery stock.

4 Native Range of EAB EAB is a destructive wood-boring beetle introduced from Asia. It is rare in its native range with little known about EAB globally at the time of its detection in the US.

5 Host Susceptibility Average survivorship of EAB is greater on North American ash species (63.3 ± 7.2%) compared to ash species with European (51.4 ± 17.0%) or Asian (26.6 ± 10.5%) origins. SIEGERT ET AL. (2014) SUSCEPTIBILITY OF SELECTED ASIAN, EUROPEAN, & NORTH AMERICAN ASH SPECIES TO EMERALD ASH BORER: PRELIMINARY RESULTS OF NO-CHOICE BIOASSAYS. NATIONAL EAB RESEARCH & TECHNOLOGY DEVELOPMENT MEETING.

6 EAB Biology & Life Cycle Adults are roughly a half inch long and dark metallic green. Life cycle generally takes one year to complete. 2-yr development typical at newly established sites. More rapid development at high EAB densities and/or in stressed trees.

7 EAB Biology & Life Cycle Larvae begin feeding in July and most finish by Oct-Nov.

8 EAB Biology & Life Cycle Extensive galleries under the bark disrupt translocation of water and nutrients in the tree.

9 Tree Decline & Mortality Foliage becomes thin, ragged and yellow. Canopy dieback progresses through the summer. North American ash of all sizes typically die in 3-5 years.

10 As of January 4, 2016 EAB Detected in 25 States

11 EAB in Ontario & Quebec

12 Tools for Detection Employing multiple trapping options improves the intensity and distribution of monitoring resources Increases the likelihood of early detection of EAB infestations in new areas

13 EAB in New England

14 % EAB Adults Natural Flight & Dispersal Physiologically capable of 0.8 miles/day. Vast majority of eggs <100 yards of emergence point. The natural EAB front moves about 2 miles/year. Distance (m) MERCADER ET AL. (2009) DISPERSAL OF THE EMERALD ASH BORER, AGRILUS PLANIPENNIS, IN NEWLY-COLONIZED SITES. AGRICULTURAL & FOREST ENTOMOLOGY, 11:

15 EAB Dispersal from Known Locations Dispersal not random or influenced by prevailing wind direction at either site. N N NW NE W W E E C 1 C 2 SW SE N m Ash Phloem Area (m 2 ) E S Ash phloem abundance appeared to influence dispersal. W SIEGERT ET AL. (2010) DISPERSAL OF AGRILUS PLANIPENNIS (COLEOPTERA: BUPRESTIDAE) FROM DISCRETE EPICENTERS IN TWO OUTLIER SITES. ENVIRONMENTAL ENTOMOLOGY, 39: S S

16 Human-Assisted Movement Pests are transported as hitch-hikers and are commonly moved along trade pathways. This has resulted in establishment of isolated satellite infestations hundreds of miles from source EAB populations. Local, national and international plant protection organizations and regulations limit this artificial spread.

17 Influence of Satellite EAB Populations Mgmt of satellite populations distant from the core infestation and near urban areas were the most economically damaging. Slowing expansion of 2009 satellites reduced damages from $ million. Suggests that spending tens of millions of dollars to prevent establishment of new satellites or slow expansion of existing populations can be cost-effective. KOVACS ET AL. (2011) THE INFLUENCE OF SATELLITE POPULATIONS OF EMERALD ASH BORER ON PROJECTED ECONOMIC COSTS IN U.S. COMMUNITIES, JOURNAL OF ENVIRONMENTAL MANAGEMENT, 92:

18 Historical Reconstruction Core infestation and several outlier sites sampled since 2004 Shiawassee Genesee Oakland Lapeer Macomb St. Clair Our sampling in southeastern Michigan encompassed the original 2002 quarantine Ingham Jackson Livingston Washtenaw Wayne Area sampled was >5,800 sq. mi (3.7 million acres) Lenawee Monroe

19 SIEGERT ET AL. (2014) DENDROCHRONOLOGICAL RECONSTRUCTION OF THE EPICENTRE & EARLY SPREAD OF EMERALD ASH BORER IN NORTH AMERICA. DIVERSITY & DISTRIBUTIONS, 20:

20 An established population of EAB was present by the early to mid-1990s.

21 Sites tend to be infested for 3-5 years before dead trees occur Coincides with current detection thresholds for EAB infestations Indiana Maryland Michigan Minnesota Pennsylvania Wisconsin

22 1998: <4 sq. miles Population Expansion 2003: >1900 sq. miles In 5 years, area occupied by the core infestation increased 480-fold.

23 Effect of Stratified Dispersal 2001 Satellite populations of EAB increase the rate of spread.

24 Radial distance (km) Population Expansion slope = 13.0 r 2 = slope = 3.8 r 2 = Year Biphasic radial expansion of the EAB invasion.

25 What s at Risk? EAB has killed nearly 100% of ash trees 2 inch diam in SE Michigan forests. Ash mortality not related to site, stand or tree traits. At least 16 native North American ash species are at risk. Fraxinus spp.

26 More Than Just a Loss of Timber Ecological effects hydrology, biodiversity, other invasive species. Cultural significance Native American basketmakers. $$$ Economic impacts $$$ ecosystem services and developed US communities.

27 EAB Management Nationally, a wide spectrum of infestation exists regional, local, & non-infested with varying proximity each with their own particular suite of appropriate & effective management responses. In general, management in areas with building EAB populations focuses on the ash resource, mitigating impacts by reducing population growth rather than eradication or control of the pest itself. More management tools now than ever before.

28 Insecticides Numerous formulations & application methods available but efficacy varies. No aerial applications for treating forested areas available at this time. Ability to protect individual high-value landscape trees.

29 Biological Control Oobius agrili (Encyrtidae) Woodpeckers Tetrastichus planipennis (Eulophidae) Spathius galinae (Braconidae) Atanycolus cappaerti (Braconidae)

30 Clusters of Girdled Trees Population sinks Influence spread of EAB populations

31 Targeted Ash Removal Reduce phloem fewer EAB produced Value for landowners

32 Integrating Tactics to Slow Ash Mortality Integrate available tools & strategies appropriate for specific sites Slow EAB population growth & spread Delay onset & advance of ash mortality

33 Emphasis on the Urban Forest EAB management in rural forests & woodlands will remain an important interest in many areas, especially those with a significant ash component. The national focus of EAB management, however, is rapidly shifting to the urban forests of our local municipalities & communities as the range of EAB expands to the southern & western states. Aesthetics, hazards, costs of treatment or removal/replacement, impacts on property values, & home heating/cooling costs are the most profound & affect the most people in our developed communities.

34 Future Direction Communities should conduct an ash inventory and assess their need for an EAB management plan. The plan shouldn t merely outline their response following EAB detection, but rather detail a short-term plan to transition through the EAB invasion. Ideally, it would be cost-effective with a clear, realistic vision of what they want their urban canopy to look like with and after the EAB invasion.

35 Future Direction A solid EAB management plan helps ensure that the community transitions through the invasion on their terms (and budget) and reduces the likelihood they simply react to the infestation without clear direction. Additionally, it increases their likelihood for consideration if state or federal funding opportunities occur in the future (response or restoration). Resources are limited and communities that have a clear vision of where they want to go & how they plan to get there will be more successful.

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