apha - david fouracre - asian hornet - bee prepared
TRANSCRIPT
Asian HornetOutbreak and response modelling
Background- who are APHA and what do we do?
• Animal and Plant Health Agency: An executive agency of DEFRA
• Role to safeguard animal and plant health- through working with vets, farmers and others
• Includes management of pests and invasive species which may have a negative impact on the UK
Asian Hornet… what is it?
• Asian Hornet is considered an Invasive Non-Native Species • Introduced to France in 2004 (native to Southern and Central Asia)• Rapidly spreading and establishing in continental Europe
Asian Hornet… why do we care?• Asian Hornet is likely to have a
significant impact on bee population in GB
• Additional cost would be reduced pollination, therefore a negative effect on plant health
• Public health risk and social concern, with Asian Hornet being closely associated with urban environments
Asian Hornet… what can we do?• Monitor for potential arrival (via bee-keepers and
public)• Work with colleagues in France to better
understand ecology and impacts• Develop techniques for finding and destroying
any nests• Work out potential arrival points, rates of
spread, likelihood of establishment, and costs of eradication
Approach• Overall requirement: To develop a spatial model that can give us a
probability of control from a given arrival point• Two tiered model:
1. lifecycle element (simulates AH spread) 2. response element (simulates human response)
• Model is spatial- takes into account landscape variability for spread and response
• Developed as a Python script, and deployed through ArcGIS desktop
Spread/lifecycle• Based on habitat suitability• Urban/suburban habitats are
‘best’, open/exposed areas (such as moorland) are ‘worst’
• Dispersal distance also accounted for
Overall landscape dispersal• Dispersal surface and habitat suitability are
added together (with a higher weighting given to dispersal)
• Simple Map Algebra (Raster Calculator) used to come up with an overall probability surface
• Nests are randomly dispersed across this surface (using sampling tools from Geostatistical Analyst)- each nest generates 4 – 20 new nests
Response• Attempts to quantify possible effort to
eradication• A search function attempts to ‘control’ the
spread• Built around the ability of a search unit (2
people) to cover ground over a month• Assumes that distance from road and
landscape type will be major factors in how long it takes to search an area
Response
1. Search begins at a random location
2. Search covers set amount of ground each month
3. Discoverable nests are removed from the production model
The Model
• Start location can be interactively placed on map
• User sets the month the start nest arrives, the full model run length, and the state of first nest
• The delay to discovery is set, along with the search resource and search type
Outputs• Spread scenarios show that
Asian Hornet may spread quickly in the UK
• Confirms what has been seen in France
• Control element is intended for use as part of a contingency package
• Further validation and engagement with bee-keepers is required
