first annual meeting forest insects & their allies current ... › biology › files › 2015...
TRANSCRIPT
1
First Annual Meeting
Forest Insects & their Allies
Current Research and Future Challenges
Thursday 16th April 2015, 10-4pm; Edge Hill University
Convenor: Anne Oxbrough
Contents
Overview 1
Schedule of Talks 2
Delegate List 3
Abstracts: Talks 4 - 12
Abstracts: Posters 12 - 15
Programme Overview
This meeting provides a forum for those interested in the field of forest ecology
to discuss current research and policy specifically related to forest insects, including
their management (e.g. pest species) and conservation. The target audience is
academics, students, practitioners and other stakeholders. This meeting received
funding from the British Ecological Society and is supported by its Forest Ecology
Group and the new Forest Insects and their Allies Special Interest Group within the
Royal Entomological Society.
9.45-10.15 Registration; Tea, Coffee, Biscuits [Business B004]
10.15-10.30 Welcome to the new special interest group
10.30-12.10 Talks
12.10-13.30 Lunch; Posters [Biosciences Foyer]
13.30-14.30 Talks
14.30-15.50 Discussion; Tea, Coffee, Biscuits [Business B004]
16.00 Conclusion and close
2
Schedule of Talks
Morning Session Chair: Anne Oxbrough
Time Title Speaker
10.15-10.30 Welcome; Why do we need a Forest Insect Special Interest Group?
Anne Oxbrough
10.30-10.50 Observations on recent surveillance for Anoplophora glabripennis by FC England
Barnaby Wylder
10.50-11.10 Ground-dwelling spider diversity in rare European oak and yew woodlands and the impact of grazing
Lauren Fuller
11.10-11.30 Thoughts on Priorities for the Conservation of Woodland Invertebrates: with aspen as an example
Alan Stubbs
11.30-11.50 Relative importance of tree species and genetic diversity for insect herbivory in boreal forests
Sandra Barantal
11.50-12.10 Can equitably mixed plantation forests support an arthropod fauna associated with both tree species?
Anne Oxbrough
Early Afternoon Session Chair: Lauren Fuller
13.30-13.50 Feeding preference and response to olfactory cues in the large pine weevil, Hylobius abietis (Coleoptera: Curculionidae)
Katrina Dainton
13.50-14.10 Can ground-based assessments of forest biodiversity
inform the biological condition of the canopy
assemblage?
Anne Oxbrough
14.10-14.30 Applications of Bioacoustics in Monitoring Forest Ecosystems
David Chesmore
Late Afternoon Discussion Session Chair: Anne Oxbrough
14.30-15.50 Round Table Discussion: Tabling of Discussion Topics Future Directions (meetings, research targets, symposia)
All
15.50-16.00 Conclusion and Close
Anne Oxbrough
3
List of Attendees
Name Organisation Email
Anne Oxbrough Edge Hill University [email protected]
Ceri Watkins Oxford University museum of
Natural History
Barnaby Wylder Forestry Commission [email protected]
Sam Jones International Pheromone
Systems LTD
David Chesmore University of York [email protected]
Lauren Fuller Forestry Commission [email protected]
Alan Stubbs Buglife [email protected]
Katrina Dainton Harper Adams [email protected]
Sandra Barantal Royal Holloway [email protected]
Neil Bennett Edge Hill University [email protected]
Ashley Lyons Edge Hill University [email protected]
Jon Delf Liverpool University [email protected]
Scott Hayward Birmingham University [email protected]
4
Book of Abstracts – Talks
Relative importance of tree species and genetic diversity for insect herbivory in
boreal forests
Sandra Barantal1, Kasey Barton2, Simon Morath1, Julia Koricheva1 (1) School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, UK, TW20 0EX.
(2) Botany Department, University of Hawaiʻi at Mānoa, 3190 Maile Way, Honolulu, HI 96822
Tree diversity alters ecosystem processes such as insect herbivory, with species-rich stands
often being less susceptible to insect damage than monoculture stands. While most of
previous studies focused on the effects of plant species richness, the effects of others
components of biodiversity such as intraspecific diversity are less investigated, especially in
forest ecosystems. We examined the relative effects of tree inter- and intraspecific diversity
on insect herbivore damage using two comparable long-term forest diversity experiments
established in boreal forests of SW Finland in 1999-2000. The tree species diversity
experiment manipulates tree species diversity (from 1 to 5 tree species planted per plot)
and the genetic diversity experiment manipulates genetic diversity of silver birch (from 1 to
8 clones planted per plot). Herbivory measurements were done on silver birch (the common
tree species between the two experiments) on 5 trees per plot in the species experiment
and 5 trees per clone per plot in the clonal experiment in early and late season in 2004,
2009 and 2014. Damage by different feeding guilds (chewers, rollers, gallers, miners) was
quantified separately. We showed significant effects of both species and genetic diversity
on insect herbivory but with opposite patterns for generalist insects (chewers). Damage due
to chewers significantly increased with genetic diversity but decreased with species
diversity. Overall, damage by specialist feeding guilds (miners and gallers) decreased with
diversity, with gallers showing an associational resistance in both clone and species mixed
stands and miners showing an associational resistance in species mixed stands only. Finally,
we found the magnitude of species richness effects on insect herbivory was higher than
genetic richness effects.
5
Applications of Bioacoustics in Monitoring Forest Ecosystems
David Chesmore
Department of Electronics, University of York, Heslington, York, YO10 5DD
Advances in low power, low cost and high speed computing have the potential to
substantially improve knowledge of forest ecosystems, biodiversity and tree health.
Bioacoustic signal identification in particular has a variety of application including rapid
biodiversity assessment, detection and identification of rare saproxylic insects in wood and
invasive pests such as Asian and Citrus Longhorn beetle (Anoplophora glabripennis and A.
chinensis), and improving early detection of tree damage. The talk will examine each of
these areas giving examples of the in-situ detection of the larvae of A.
glabripennis/chinensis and native Coleopteran pests (e.g. Anobium punctatum, Agrilus
biggutatus) together with future developments in holistic monitoring of tree health
(mechanical damage, decay, insect damage). The talk will also consider the development of
long term data loggers and wireless networks for long term continuous monitoring over
large geographic scales. The final part of the talk will consider the development of
automated species identification systems for rapid identification of acoustically active
animals, birds and insects and give examples of recently deployed systems. If time permits,
a demonstration of acoustic signals from live A. punctatum larvae will be given.
6
Ground-dwelling spider diversity in rare European oak and yew woodlands and the
impact of grazing
Lauren Fuller
Forest Research, Forestry Commission, Alice Holt
In Ireland only 2 % of the total land area is native woodland, which tends to be small and
fragmented. Killarney National Park in south-west Ireland contains the most extensive semi-
natural woodland in the country, and includes oak (Quercus petraea) and yew (Taxus
baccata) woodlands which are internationally protected. Here, over-grazing by large
populations of red deer (Cervus elaphus) and Asian sika deer (Cervus nippon) have lead to
changes in overstory and understory vegetation species composition and structure. This
study presents the first description of ground-dwelling spider fauna in the rare woodlands
of Killarney National Park and asked (1) do these rare woodlands support rare or specialist
species, (2) does deer grazing have an effect on spider abundance, richness and species
composition in the park, (3) what management recommendations can be made for deer in
the park? Active ground-dwelling spiders were sampled in the oak and yew woodlands of
the park by pitfall trapping within deer-proof exclosures and adjacent grazed controls. Four
spider species classified as vulnerable were collected from these woodlands: Agyneta
subtilis occurred in the oak and yew woodlands but Saaristoa firma, Tapinocyba insecta and
Walckenaeria dysderoides were collected only in the oak woodland. Killarney National Park
may be important for five species, not typically found in plantation forests, which rely on
nationally scarce habitats. Deer grazing was linked with decreased ground dwelling spider
abundance and species richness in the oak woodland by reducing structural diversity of the
habitat. Fewer effects of grazing were detected in the yew woodland, possibly due to
increased culling in the area. Results provide evidence that controlling deer grazing is
important for woodland biodiversity in Killarney National Park. Incorporating deer into
woodland management in the park is recommended to maintain low grazing levels which
will prevent woodland closure and maintain ground vegetation diversity.
7
Feeding preference and response to olfactory cues in the large pine weevil,
Hylobius abietis (Coleoptera: Curculionidae)
Katrina Dainton
Harper Adams University
Hylobius abietis is a major pest of coniferous clear-fell and restocking Eurasian forestry
sites, which provide an abundance of suitable habitat and where adult weevil herbivory
causes seedling mortality. Despite extensive research into H. abietis biology and control
methods, gaps remain in the understanding of H. abietis feeding preferences and
behaviour. This study investigated the feeding behaviour of Hylobius abietis in choice and
no choice tests with five tree species: Pinus sylvestris (Scot’s pine); Pinus nigra var.
corsicana (Corsican pine); Picea sitchensis (Sitka spruce); Betula pendula (Silver birch) and
Larix decidua (European larch). The impact of volatiles released from prior herbivory was
also investigated in paired choice tests between artificially girdled and non-girdled twigs of
the same tree species. Y-tube and four-choice olfactometer experiments further
investigated adult H. abietis responses to olfactory cues from food stimuli. Pinus sylvestris
was preferred, Betula pendula was not preferred and overall hierarchal feeding preference
order of P. sylvestris > P. sitchensis > P.nigra var. corsicana > L. decidua >> B. pendula.
Feeding rates did not differ between males and females, but males were more active in
response to olfactory cues than females and showed some aggregation tendencies. A
number of adults were parasitised during experiments, which is discussed in terms of
potential biological control agents. All results are discussed in relation to Integrated Pest
Management strategies.
8
Can equitably mixed plantation forests support an arthropod fauna associated with
both tree species?
Anne Oxbrough 1, Sergio Garcia-Tejero 1, John Spence 3, John O’Halloran 2
1 Edge Hill University; 2 University College Cork, Ireland; 3 University of Alberta, Canada
Tree species composition is a key driver of forest biodiversity, influencing structural
components of the environment from soil and litter to vegetation layers and the canopy,
and ecosystem processes, such as nutrient cycling. Single species stands, particularly
intensively managed monoculture plantations, are typically more homogenous in habitat
structure and the biotic communities supported, than mixed stands. Thus, international
forest policy increasingly promotes the establishment of mixed plantation stands as an
alternative to enhance biodiversity in plantations. Research by Oxbrough et al 2012 has
shown that there is limited biodiversity value from an additional canopy species comprising
15-40% of the mix, at least for the groups studied (ground-dwelling spiders and Carabid
beetles, and night-flying macrolepidoptera). This paper determines the potential
biodiversity value of equitable mixes (50:50% ratio of each tree species) in Irish plantations,
using ground-dwelling spiders, carabid beetles and staphylinid beetles as indicator groups.
Implications for forest policy, where recommendations are often based on the proportion
of each mix component, are discussed.
9
Can ground-based assessments of forest biodiversity inform the biological
condition of the canopy assemblage?
Scott M. Pedley1, Anne Oxbrough2, Rebecca D. Martin1, Sandra Irwin1, Thomas C.
Kelly1, John O’ Halloran1 1 University College Cork, Ireland; 2 Edge Hill University, UK.
Biological assessments of forest systems often involve a single ground-invertebrate
sampling method that either ignores or indirectly infers the biological component of the
non-sampled canopy. Pitfall trapping for ground-active arthropods is a widely implemented
technique for biological assessment in forested and open habitats. Although much evidence
highlights the biases of pitfall trapping, this evidence comes from open habitat crop and
grassland systems. In forest system where much of the biodiversity is within the three
dimensional aboveground structure, management recommendations based solely on
ground sampling may not represent the majority of the forest biota. We provide evidence
from combined ground and canopy sampling of three major forest types within the study
region. We use canopy insecticide fogging to compare to more traditional ground-based
pitfall trapping and use spiders as a comparative species-rich biota that is able to colonise
most terrestrial habitats and is strongly affected by changes in environmental condition.
Both types of sampling defined community composition differences between the forest
types in a similar manner; therefore, either method could be used to evaluate differences
and test management regimes in well-replicated experiments of forest type. However, if
detailed information regarding habitat guilds, body size or habitat inventorying is required
then separate targeted surveys are required. Comparisons using solely species incident
obtained by either survey method should be avoided. This coarse metric reduces data
complexity, is strongly influenced by non-specialist species and can be highly susceptible to
sampling effort and methods especially in habitats that contain numerous uncommon
species.
10
Observations on recent surveillance for Anoplophora glabripennis by FC England
Barnaby Wylder
Forest Health Officer, Forestry Commission, North West Region
The Forestry Commission England Tree Health Team were requested to undertake
surveillance of trees surrounding, and look at material within the actual premises of
companies importing products using wood packaging material (WPM) coming from places
with a potential risk of carrying Anoplophora glabripennis (Asian Longhorn Beetle) during
the winter months of 2014/15. A non-exhaustive desk-top exercise identified over 300
potential points for surveillance across the five regions of England, of which over 100 were
surveyed. Although no live Asian Longhorn Beetle were identified, larval galleries and
pupation chambers were occasionally intercepted, and there were around 20 instances
where expert advice was sought from Forest Research entomologists. Findings did include
signs suggestive that WPM was not being treated appropriately in all instances to ensure no
insects would survive processing, along with systemic failures to adhere to regulations for
treating, preparing and identifying WPM particularly associated with one country, with
occasional infringements from other countries.
11
Thoughts on Priorities for the Conservation of Woodland Invertebrates: with aspen
as an example
Alan Stubbs
Vice-President, Buglife – The Invertebrate Conservation Trust
Aspen is recorded from nearly all 10 squares except for most outer islands so its fauna
ought to be safe, even without paying any attention to it. Yet there have been 8 extinctions
of aspen dependent British insects since 1900 and a further 9 are Priority Species within the
Biodiversity Action Plan. Taking for granted that invertebrates can look after themselves
and flourish is not an option if habitat conservation and maintaining biodiversity is to be
taken seriously.
At the first meeting of this SIG, I table some of the other priority issues,, such as the need
for flowers (scrubs & herbs); Deer browsing (sapling/coppice inhibition & herb layer
reduced to monocotyledons); Ride & glade quality: Structure; Planting new woodland needs
planting of key shrubs and herb layer; Saproxylic habitat (decaying wood etc., tree cohort
age gaps); Woody debris in streams; Importance of ground water seepages, springs and
streams; Options for enhancing invertebrate faunas in plantations; Re-establishment of lost
species from woods/choices and practicalities; Pest control measures (especially when
impinging outside commercial forests).
It is important to clarify what is known and where the significant gaps in knowledge need
addressing.
12
Book of Abstracts – Posters
Do mixed conifer species stands support greater spider diversity than
monocultures.
Neil Bennett, Edge Hill University
Biodiversity is key to underpinning ecosystem function in forests; as such UK forest policy
aims to support biodiversity through sustainable forest management. Large-scale planting
across the UK has seen an increase in monoculture plantations. However, they are
unnatural and are thought to support lower biodiversity than semi-natural forest. One way
to promote biodiversity is to establish more diverse forest types such as mixes. This project
aimed to examine differences in spider assemblage structure between monocultures and
50:50 mixed-species stands in an established experimental site in Gisburn forest. We found
that there was little difference in species richness and abundance across forest types but
the spider communities supported differed significantly. We suggest that in order to
support forest biodiversity in the long term, mixed species stands should be considered as
an essential practice in forest management.
13
Can spruce plantations support a diverse and forest-associated arthropod fauna?
Anne Oxbrough1, Veronica French2, Patrick Smiddy2, Sandra Irwin2, Thomas C.
Kelly2, John O’Halloran2
1Edge Hill University; 2University College Cork
Plantation forests constitute a large proportion of the forest estate in many countries,
particularly in the temperate regions of Europe. In countries like Britain and Ireland, a large
proportion of these plantations are comprised of non-native conifers, particularly Picea
sitchensis and Picea abies. Furthermore, cover of natural woodlands is declining and they
are becoming increasingly fragmented within intensively managed agricultural landscapes.
In light of this, it is important that the potential of these plantations to support a diverse
flora and fauna, particularly of forest-associated species, is assessed. We compared
arthropod diversity in pure stands of P. sitchensis and P. abies, and also in P. abies mixed
stands with native species to that in native woodlands in forty five sites across Ireland.
Spiders and Carabid beetles were sampled with pitfall traps and moths were sampled using
light traps. A range of environmental parameters were measured including vegetation
cover, stand structure, soil attributes, and landscape variables such as forest cover.
Invertebrate species composition and richness differed between plantations and native
woodlands, particularly for key forest-associated species. However, conifer dominated
stands mixed with native species did not support fauna associated with semi-natural
woodlands. Responses also differed by taxonomic group. At the stand scale arthropods
were related to litter and vegetation cover, whereas amount of forest cover within 1km was
important for moths. These findings suggest that forest policy aimed at promotion of
biodiversity in plantations should support greater diversity of stand structure and tree
species composition. Although planting of species of native provenance has increased in
recent years, particularly in mixed stands, this trend should be encouraged further, by
increasing the proportion of these species in a mix.
14
Selection appropriate sampling methods for ground-dwelling arthropods in
biodiversity assessment
Sergio Garcia-Tejero 1, Stephane Bourassa 2, Anne Oxbrough 1
1 Edge Hill University, United Kingdom; 2 University of Alberta, Canada
Appropriate arthropod sampling schemes are essential for sound conservation and ecology
studies. Pitfall trap sampling is a favoured method when surveying litter-dwelling arthropod
assemblages such as spiders and beetles. However, pitfall trap captures are affected by
differences in species behaviour and may bias captures towards larger and highly mobile
species. On the other hand, direct litter sampling methods provide much more accurate
estimations of species abundance and may find species not detected by pitfall traps but
may require higher fieldwork effort. In this study we compared the performance of pitfall
trap and Berlese-Tullgren extraction methods for surveying litter-dwelling spiders, carabids
and staphylinids in a variety of forest types in Canada, with the aim of informing best
practice for biodiversity assessment. Number of captures varied highly between the studied
groups, sampling methods and forest habitats. Some species were exclusively captured by
one method while the numbers of others greatly differed between both techniques. The
advantages and flaws of these sampling tools are discussed focusing on their cost-efficiency
and its accuracy to render proper composition patterns for biodiversity, ecology and
conservation studies.
15
The role of environmental heterogeneity in determining arthropod diversity in
boreal forests
Anne Oxbrough 1, Sergio Garcia-Tejero 1, Stephane Bourassa 3, John O’Halloran 2,
John Spence 3
1 Edge Hill University; 2 University College Cork, Ireland; 3 University of Alberta, Canada
Forest management typically leads to homogenous environments at stand and landscape
scales, as well as at a small-scale, among microhabitats. There is a need to determine the
influence of this homogeneity on forest biodiversity. Arthropods are key components of
forest biodiversity, playing functional roles in food webs as herbivores, predators, as a food
source for mammals and birds, but also as decomposers and pollinators. We measured
environmental heterogeneity (as measured by structural characteristics, soil parameters
and stand type) in the boreal mixed woods of Alberta, Canada. Arthropods from several
functional groups (spiders, carabid and staphylinid beetles) were collected with pitfall traps
across a range of successional stages and following clear-cutting. We found that habitat
heterogeneity was greater in mature stands and later successional stages, and management
had the greatest effect on beta diversity and heterogeneity at small scales (20-40m).