9:04 a.m.
Predicting the development and spread of Emerald Ash Borer in Britain and Western Canada
Forest Entomology PhD Studentship
University of Toronto, Natural Resources Canada Canadian Forest Service, and Forest
Research UK
A PhD studentship is available to work as part of an international research group
investigating the risks of establishment by the invasive Emerald Ash Borer beetle into the
UK, northern Europe, and western Canada. By exploring the beetle's relationship with
temperature and host resistance, the project will determine how the cooler climates of
these regions will influence the life cycle and rate of spread of EAB, model its potential
impact upon different ash tree species, and ensure management strategies are the most
appropriate for the climatic context.
Introduction
Emerald Ash Borer, Agrilus planipennis (EAB) is a buprestid beetle native to China, Korea
and Japan where it is a secondary pest of stressed and moribund ash trees (Fraxinus
mandshurica and F. chinensis) and has no economic impact. Since its accidental
introduction into North America however, it has had a devastating impact on all native ash
species, including green, white and black ash (F. pennsylvanica, F. americana and F.
nigra), which are highly susceptible to attack. Trees are killed within 3-5 years, and
where the beetle is well established up to 99% of ash trees have been lost. Infestations
have been reported from large areas of southern Ontario and Quebec in Canada, and in 30 US
states, and the beetle is still spreading. Hundreds of millions of ash trees have been
killed in the USA and Canada to date.
EAB has also been accidentally introduced to Russia, where it has spread outwards from
Moscow on American green ash planted along roadsides. The threat to ash in Europe is now
severe as EAB spreads south-west in Russia into areas where European ash, Fraxinus
excelsior is a natural component of the landscape. From here the pest is expected to be
able to spread unhindered toward central and western Europe. There is still considerable
uncertainty however, over how susceptible F. excelsior is to attack. Field trials in the
USA suggest that it is highly susceptible to EAB, but observations in Moscow indicate that
not all F. excelsior are attacked and this species may possess a degree of resistance.
Another major uncertainty over the likely impact of EAB in Europe is how far and how
rapidly the beetle will spread, particularly in the cooler maritime climate of the north
and west. The current distribution of EAB in the USA, Canada and Moscow, encompasses areas
with a continental climate and relatively high summer temperatures. It is not known
whether EAB will perform equally well under a cooler and wetter climate such as that in
the UK, and whether this might limit its rate of spread, abundance, and impact on ash
trees.
Life-cycle duration and dispersal opportunities in insects are largely governed by
temperature. For example, Asian longhorn beetle (Anoplophora glabripennis) has also been
introduced into both North America and Europe, is similarly adapted to benefit from high
summertime temperatures. Analysis of a recent outbreak in the UK showed that the beetle
required 3 years to complete its life-cycle, compared to only 1 year in continental
regions with higher summertime temperatures. Limited opportunities for dispersal also
meant that the population remained small and contained, in a way not seen in warmer
climates. The cooler summer temperatures experienced in the UK and in western Canada may
similarly influence the life cycle and flight dispersal opportunities for EAB once it
establishes there. The limited data available on the thermal requirements for EAB suggests
an optimum development temperature of 25-30°C. In comparison, mean summer temperatures in
forest habitats in the UK and western Canada are often around 15-20°C. Thus in combination
with a potentially more resistant host tree in F. excelsior in Europe, it is possible that
EAB populations may increase and spread more slowly than has been observed to date. This
may provide opportunities to manage it in a way not achievable in its current outbreak
area.
Project aims
This project will determine the relationship between temperature and development rate for
all life stages of EAB, so that we can predict how the beetle will perform in the cooler
climate of the UK and western Canada. We will establish these relationships through a
series of experiments in which the different stages of the beetles are reared across a
range of temperatures (7-30°C), and on different Ash tree species suspected to vary in
their resistance to EAB. The data obtained will then be used to construct phenological and
population models to assess the likelihood of establishment in the UK, northern Europe,
and western Canada, as well as its potential rate of increase and spread, and likely
impact on forest health. These models in turn will provide a basis for assessing the
future economic impacts of EAB and an indication of the resources likely to be required in
the future to deal with an introduction and subsequent outbreak. Understanding the
potential rate of increase and spread into these new areas would enable hypotheses to be
tested comparing different management strategies.
Experimental research will be conducted by the PhD student at the Natural Resources Canada
Canadian Forest Service's Great Lakes Forestry Centre (GLFC) in Sault Ste. Marie,
Ontario, Canada; other studentship requirements will be fulfilled at the Faculty of
Forestry, University of Toronto. There will also be the opportunity to visit ongoing
Forest Research programs in the UK. Supervision will be provided by Dr Chris MacQuarrie
(GLFC), Dr Daegan Inward (Forest Research, UK), and Professor Sandy M. Smith (University
of Toronto).
Applications will be accepted up until December 2017, but Interested students are strongly
encouraged to contact project leaders as soon as possible to discuss an earlier start
date. Contacts include: Prof. Sandy M Smith, Faculty of Forestry, University of Toronto
(s. smith.a@utoronto.ca<mailto:s.smith.a@utoronto.ca>), Dr. Chris MacQuarrie,
Canadian Forest Service, Sault Ste Marie
(christian.macquarrie@canada.ca<mailto:christian.macquarrie@canada.ca>) or Dr.
Daegan Inward, UK Forest Commission
(Daegan.Inward@forestry.gsi.gov.uk<mailto:Daegan.Inward@forestry.gsi.gov.uk>).
Information on the formal application process and guaranteed stipend support for PhD
programs at the Faculty of Forestry can be found at:
http://forestry.utoronto.ca/phd-degree-requirements/ and
http://forestry.utoronto.ca/phd-and-mscf-funding/. Additional information for the
University of Toronto graduate school is available at:
https://www.sgs.utoronto.ca/prospectivestudents/Pages/Frequently-Asked-Ques….
Please Note: Funding will be available for 4 years and is targeted to Canadian citizens,
however exceptional international students (i.e. hold a competitive academic average of A
or better equivalency; see School of Graduate Studies admissions site for information on
equivalent international
qualifications<http://portal.sgs.utoronto.ca/current/admission/intdegequiv.asp>, and
meet all other academic requirements) may be considered if they are eligible for
post-graduate scholarships through the University of Toronto.
Research Scientist, Canadian Forest Service
Natural Resources Canada / Government of Canada
Christian.MacQuarrie@canada.ca<mailto:Christian.MacQuarrie@canada.ca> / Tel:
705-541-5666
Chercheur scientifique, Service canadien des forêts
Ressources naturelles Canada / Gouvernement du Canada
Christian.MacQuarrie@canada.ca<mailto:Christian.MacQuarrie@canada.ca> / Tél. :
705-541-5666
Tandberg 77055415666
Twitter @cmacquar