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Managing Spotted Wing Drosophila (SWD) in the UK: Determining its distribution and seasonal population dynamics. - CH0203

Spotted wing drosophila (SWD) is a newly arrived, highly damaging pest of a wide range of soft and stone fruits which spreads and can build up very rapidly. Females have a serrated ovipositor enabling them to lay eggs in fruit as it starts to ripen, unlike our native Drosophila species that can only lay eggs in overripe fruit. Larvae feed inside the fruit causing a rapid degradation in fruit quality rendering it unmarketable. Temperature and humidity conditions in UK soft and stone fruit crops, especially polytunnels are probably ideal for SWD. Experience in other countries indicates that monitoring for adults and for larval infestation in fruit through the season in all crops at risk is vital. Control is by programmes of sprays of organophosphate, synthetic pyrethroid and spinosyn insecticides, targeted against adults. Once egg laying females have been recorded, a 7 day programme of sprays of suitable insecticides is applied, from when the fruit starts to colour to the end of harvest, rotating insecticide groups to reduce the risk of resistance. If the pest becomes widespread in the UK, there will be a significant increase in the use of broad-spectrum pesticides. This will have adverse environmental consequence as well as seriously disrupting IPM and could make production of some crops much more difficult or even impossible in the UK.

In this project, the distribution of SWD in the UK and the seasonal population dynamics of its different life stages in relation to crop ripeness and wild hosts, which are unknown in the UK, will be quantified to inform control tactics. The relationships between adult catches in monitoring traps and larval attacks in different vulnerable fruits and common UK wild hosts will also be quantified.

The project forms part of a larger programme being funded by industry and has been agreed by the UK industry to meet their vital requirements, filling gaps that are not being addressed in research programmes in other countries. Industry will be involved in selecting study sites and carrying out observational work at these sites. It addresses Defra’s Evidence Investment Strategy 2010-2013 (updated 2011) policy Annex 2, Section 10. Crops. Section 24. Plant health, Bee Health and Plant Varieties and Seeds. It is vital for maintaining the viability and profitability of the UK’s important soft and stone fruit industries. SWD seriously threatens the sustainability of production of these crops in the UK.
To determine the distribution and seasonal population dynamics of all life stages of SWD in different cropping situations and especially polytunnel crops on fruit farms in the UK
Time-Scale and Cost
From: 2013

To: 2014

Cost: £75,000
Contractor / Funded Organisations
East Malling Research
Horticulture Development Council (HDC)