-Asian longhorned beetle (Anoplophora glabripennis Motschulsky) (ALB) has invaded multiple areas in the United States and several other countries,.
Using dendrochronology to reconstruct the time of introduction and spread of the invasive Asian longhorned beetle (Anoplophora Stephen M. Todd , Emily Franzen , Scott Gula , Bill Panagakos , Ann M. Ray glabripennis Motschulsky) Department of Biology, Xavier University, Cincinnati, Ohio 1
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USDA APHIS PPQ CPHST, Otis Laboratory, Buzzards Bay, Massachusetts
Results
Goal
Methods -We selected trees to sample a range of distances from the suspected site of introduction (250m to 4,800m) -Forty-eight trees were felled within the quarantine zone in Bethel, Ohio and sections measuring 60-100 centimeters from each tree were brought to the laboratory -We identified sites of damage and marked them for further dissection -We made disks by cutting through the marked site and making a second cut 3-15 cm away with a miter saw -The side of the disk with the marked site was sanded with a belt sander until the tree rings were easily visible -We counted tree rings from the edge of the xylem to the damage site (see scan below)
Determine the year that Asian longhorned beetle first established in Clermont County, OH.
Background -Asian longhorned beetle (Anoplophora glabripennis Motschulsky) (ALB) has invaded multiple areas in the United States and several other countries, thus becoming a worldwide pest (Hu et al. 2009) -Larvae disrupt the vascular tissue of the tree while feeding, causing structural weakness which, after repeated attack, leads to the death of the tree. This damage could exceed $669 billion in the U.S. (Nowak et al. 2001) -ALB adults were first discovered in Clermont County in 2011, but may have been present for several years before detection, similar to the infestation of emerald ash borer (Agrilus planipennis Fairmaire) that went undetected in Michigan for nearly a decade (Trotter and Hull-Sanders et al. 2015, Poland et al. 2015) -Detecting ALB activity is challenging in heavily forested suburban locations because the canopy is thicker and host species are more prevalent. Ground survey teams are only 30% effective at making a positive identification of an infested tree, and climbing crews are 60% effective (Smith et al. 2009) -In the field, average seasonal dispersal of ALB adults is 920m, and maximum seasonal dispersal is 2600m (Trotter et al. 2015). In flight mill studies, the average distance flown is 2300m in 24 hours, and the maximum distance flown is 13700m in 24 hours (Lopez et al. 2017) -Adult female ALB chew into the bark when depositing eggs, and adults will chew out of the bark when they emerge. These wounds heal over time, leaving characteristic “scars” in the host tree, which provide a record of the activity of ALB -By examining the growth rings in thin cross sections of an infested tree, we can analyze this record to determine the time of introduction (Graham et al. 2010)
Figure 4 The photo to the left is a scan of a dissected egg site. The egg site is labeled and denoted with an arrow. The growth response is within the bracket, and the year indicates the year that it is from. This egg site dates to 2012.
Year 2007 2008 2009 2010 2011 2012 2013 2014 2015
Color red orange yellow green blue maroon brown grey black
Figure 3 This map shows the infestation area in Bethel, which is located in southwest Ohio (see locator map). Each colored dot represents a sampled tree, and the black dot in the center of the red circle indicates the suspected epicenter of the infestation. Each colored ring indicates 1000m, which is the average dispersal distance for one year.
Three egg sites and two exit holes were dated to 2007. This indicates that adults were present the previous year because ALB requires at least one year to develop from egg to adult. Thus, we hypothesize that introduction occurred in Bethel, OH as early as 2006.
Acknowledgments We thank Mackenzie O’Kane for her assistance, and the residents of Bethel, Ohio for allowing us to sample their trees. We also thank the USDA survey teams, USDA climbers, and contracted climbers for their help in locating and felling infested trees. Figure 1 Past and current infestations of ALB in North America are represented by white boxes, and forests at risk are shaded in yellow.
Figure 2 ALB egg site circled in black.
References Graham, E.E. (2010). Host plant relationships and chemical communication in the Cerambycidae (Doctoral dissertation, University of Illinois at Urbana-Champaign). Retrieved from http://hdl.handle.net/2142/16082 Hu, J., S. Angeli, S. Schuetz, Y. Luo, and A. Hajek. 2009. “Ecology and management of exotic and endemic Asian longhorned beetle Anoplophora glabripennis.” Agric. Forest Entomol. 11, 359-375. Lopez, V., M. Hoddle, J. Francese, D. Lance, A. Ray. 2017. “Assessing flight potential of the invasive Asian longhorned beetle (Coleoptera: Cerambycidae) with computerized flight mills.” J. Econ. Entomol. doi: 10.1093/jee/tox046 Nowak, D., J.E. Pasek, R.A. Sequeira, D.E. Crane, V.C. Mastro. 2011. “Potential effect of Anoplophora glabripennis (Coleoptera:Cerambycidae) on urban trees in the United States.” J. Econ. Entomol. 94, 116-122. Poland, T., Y. Chen, J. Koch, D. Pureswaran. 2014. “ Review of emerald ash borer (Coleopter:Buprestidae), life history, mating behaviors, host plant selection, and host resistance.” Can. Entomol. 147, 252-262 Smith, M.T., J.J. Turgeon, P.D. Groot, and B. Gasman. 2009. “Asian longhorned beetle Anoplophora glabripennis (Motschulsky): lessons learned and opportunities to improve the process of eradication and management.” Am. Entomol. 55:1, 21-25. Trotter, R.T., and H. Hull-Sanders. 2015. “Quantifying dispersal of the Asian longhorned beetle (Anoplophora glabripennis, Coleoptera) with incomplete data and behavioral knowledge.” Biol. Invasions. 17, 3359-3369.
