This project will focus on the oak lace bug (OLB) Corythucha arcuata (Heteroptera: Tingidae) an invasive Hemipteran insect introduced from its native range in N. America into Europe, and which was first detected in Europe in Italy in 2000 (Bernardinelli & Zandigiacomo, 2000).
Since its accidental introduction it has spread rapidly over a wide geographical area and is now found in over a dozen other European countries. In some countries, such as Hungary and Croatia its population has reached substantial levels where there is now serious concern that the pest may have significant impacts on oak health, as well as potentially increase the susceptibility of oaks to other pests and diseases.
OLBIE – Work packages
The project is comprised of six work packages with inter-related objectives that will address key questions and gaps in the knowledge of the oak lace bug (Corythucha arcuata) particularly in relation to the biology, dispersal, control and management options.
Work package 1: Project Management and Co-ordination (Lead: FR)
- Overall project management and co-ordination of delivery and results reporting.
- Establish website
- Communication strategy
Work package 2: Review evidence of impacts (Lead:
- Impacts on growth and development – linked to defoliation/canopy loss/% canopy affected. Assessment of all tree age classes, are young trees susceptible to mortality? Dendrochronology studies?
- How is acorn production (numbers and size)/germination rates/seedling survival affected?
- Interactions with other abiotic/biotic factors (probably only detectable over longer periods of time) – is there increased susceptibility following drought or defoliation by other insects, and fungi? Consider also cumulative impacts of drought + defoliators (e.g. oak processionary moth or gypsy moth) + Corythucha arcuata + wood borers + oak mildew.
- Do impacts differ between forest and urban settings?
- What insect pest population levels cause what levels of damage? How quickly do populations build up to these levels once established?
- Why are there apparent differences in the impacts between Italy/Switzerland where there appear to be no accounts of serious damage/impacts and the seemingly heavily affected areas in Hungary/Croatia?
- Identify and prioritise research and evidence needs
Work package 3: Prevention and detection (Lead: BFW, Austria)
- Developing surveying techniques/protocols to detect Corythucha arcuata as early as possible in new areas
- Reviewing, evaluating and testing early detection methods/trapping techniques
- Evaluation of potential pathways
- Is it possible to monitor spread in a cost-effective manner?
- Which control approaches are feasible in response to early detection?
Work package 4: Natural and human mediated spread (Lead: FR)
- What are the natural rates of spread?
- What spread is there with commodities, timber, firewood, plant trade, – how did arcuata get introduced into Europe? Can it be introduced again at other sites? How is it being spread within Europe?
- Any evidence of hitch-hiking?
- Consider climate effects on rates of spread and numbers of potential generations per year.
Work package 5: Pest management (Lead:
- Chemical control options? Methods of application? Consider approaches in urban and forest settings.
- Biological control options? What are the predators/parasitoids associated with Corythucha arcuata in its native range? Is it possible to augment existing European predator/parasitoid communities?
- Are there any management approaches to dealing with the pest in the countries where it is well established?
- Treatment options for felled trees, logs, timber prior to transportation? Is debarking or chemical control an option since adult arcuata over winter in bark crevices and cracks
- Host resistance? Is there any evidence that there are less susceptible species of oaks?
- Is any control viable/cost effective or is it inevitable that oak lace bug will spread across Europe (cf Sycamore lace bug)?
Work package 6: Engagement (Lead:
- Raise awareness of OLB (& OLBIE) to stakeholders and the general public
- Outreach programmes?
- Observatree/Life Artemis – citizen science projects (searching/trapping for the pest; raising public awareness; webinars; posters; booklets)
- Review impacts of aesthetics of brown/discoloured oaks in urban environments (cf horse chestnut trees and Cameraria ohridella)
- Explore social acceptance of potential control and management approaches (cf work on oak processionary moth in UK)
The main objective(s) that will be considered by the collaborators involved in the project will include:
• What are the impacts of this insect pest on oak growth and fecundity, and why is there such variability in the insect’s apparent impacts across Europe (i.e. high impacts in Croatia and Hungary, and seemingly low impacts in Italy and Switzerland?)
• What are the key pathways for movement of the insect pest and how can we better protect against the risk of further introductions and wider European spread?
• What are the rates of natural spread, and what are the key human mediated means of dispersal of the pest?
• What are the best survey strategies to try and detect the pest as early as possible?
• What control and management approaches are available, cost-effective and of use in dealing with this pest? Is there scope for biological control? And ultimately is there scope for preventing or limiting spread in the case of successful establishment?
Observatree – Oak lace bug
Evaluation of the pest status in Europe of the oak lace bug (Corythucha arcuata): Poster presented at IUFRO conference in Quebec City
Forest Research are the project co-ordinators