白蜡窄吉丁虫-ashes to ashes-eab

Diversity and Distributions, (Diversity Distrib.) (2006) 12, 71–79

BIODIVERSITY

RESEARCHModelling local and long-distance dispersal of invasive emerald ash borer

Agrilus planipennis (Coleoptera) in North

America

Jim R. Muirhead1, Brian Leung2, Colin van Overdijk1, David W. Kelly1,

Kanavillil Nandakumar1, Kenneth R. Marchant3 and Hugh J. MacIsaac1*

Great Lakes Institute for Environmental

Research, University of Windsor, Windsor,

Ontario N9B 3P4; 2Department of Biology,

McGill University, Montreal, Quebec H3A

1B1 and 3Canadian Food Inspection Agency,

Guelph, Ontario N1G 4S9, Canada 1ABSTRACT

*Corresponding author. Dr. Hugh MacIsaac,

Great Lakes Institute for Environmental Research,

University of Windsor, Windsor, Ontario N9B

3P4,Canada. Tel.: (519) 253-3000 ext. 3754; Fax

Limiting the damage by non-indigenous species requires rapid determination of currentand potential distributions and vectors of dispersal, and development of appropriatemanagement measures. The emerald ash borer (Agrilus planipennis), a wood-boringbeetle native to South-East Asia, was rst reported in the Great Lakes region duringsummer 2002. The beetle poses an enormous threat to native ash (Fraxinus) speciesof North America, as untreated trees in infested areas of Ontario, Michigan andOhio suffer high mortality. We demonstrate that the borer has spread in NorthAmerica through a combination of diffusive range extension, associated with local ights, and by long-distance ‘jump’ dispersal associated with human movement ofinfested sapling or contaminated rewood. Probability of infestation was inverselyrelated to distance from borer epicentres but positively related to the size of humanpopulation centres. At least 9 of 39 populations that were rst reported in Michiganduring 2004 cannot be accounted for by local diffusion, raising the possibility thatother unidenti ed mechanisms may be contributing to the dispersal of the beetle. Inthe absence of quarantine, by 2005 all of Michigan’s lower peninsula was containedwithin the boundaries of potential diffusive range expansion. Infested ash saplingsalso were introduced from Michigan to Maryland during 2003, and subsequentlytransplanted to ve sites in Maryland and Virginia. Quarantine and eradicationmeasures have had mixed results: in the south-central USA, the species appears onthe brink of eradication, whereas its distribution has continued to spread during

2005 in the Great Lakes region despite extensive containment and quarantine meas-ures. Quarantine success in the Great Lakes region is encumbered by multiple dis-persal vectors, larger borer population sizes and by the more extensive geographicaldistribution that was achieved prior to implementation of control measures.KeywordsDispersal kernel, gravity model, Great Lakes, invasive, non-indigenous species,INTRODUCTION

Dispersal is fundamental to species distributions and ecology.

With a history that dates back to Darwin, dispersal remains one

of the most intensively studied elds in ecology (e.g. Clobert

et al., 2001; Bullock et al., 2002; Nathan, 2005). In recent years,

attention has focused on the relative contributions of local and

long-distance dispersal and their consequences for species ranges,

patterns of dispersal and population persistence (e.g. Lewis,

1997; Higgins & Richardson, 1999; Levin et al., 2003; Green &

Figuerola, 2005; Trakhtenbrot et al., 2005). Biological invasions

© 2006 Blackwell Publishing Ltddoc.guandang.net non-indigenous species represent an important appliedextension of dispersal ecology since, in many cases, human-mediated dispersal transports a signi cant number of individualsto distances farther from the source than they could dispersenaturally (e.g. Hebert & Cristescu, 2002). As with their counter-parts in basic ecology, invasion biologists have focused on therelative importance of local vs. long-distance dispersal (With, 2002,2004; Neubert & Parker, 2004; Hastings et al., 2005; Puth & Post,2005). Long-distance dispersants provide opportunities for‘nascent foci’ to develop, from which new populations orcoalescing nodes can be founded (Moody & Mack, 1988; Lewis,DOI: 10.1111/j.1366-9516.2006.00218.x71