Title: Population biology of Spotted Wing Drosophila (Drosophila suzukii)

Supervisor(s): Prof Mike Bonsall (Zoology [email protected] - 01865 278916) with colleagues from University of Lincoln (Professor Mat Goddard; School of Life Sciences) and University of Cambridge (Professor Steve Russell; Department of Genetics)

Dates: August/September 2017

Project Proposal:

Drosophila suzukii is an invasive species that attacks ripening fruit on the plant, unlike other Drosophila species which only feed on overripe or spoiled fruit (EPPO, 2010; Rota-Stabelli et al. 2013). D. suzukii was found for the first time in the UK in wild blackberry in Kent in August 2012 (Harris and Shaw 2014) and is now a serious pest in most soft and stone fruits in the UK.

Drosophila suzukii is now widespread worldwide causing substantial crop and financial losses. In 2008 economic losses for California, Oregon and Washington were 40% (blueberries), 50% (caneberries), 33% (cherries) and 20% (strawberries), approximately $511 million in damages annually (Bolda et al. 2010; Goodhue et al. 2011). In 2009 in California D. suzukii destroyed ~25% of cherry crops, 80% of Oregon peach crops and 20% of raspberry crops (Agriculture Canada newsletter). The annual costs to control D. suzukii in Oregon’s affected small fruit industries was $12-16 M p.a. (Julian et al. 2011), not including market loss, processing the fruit or rejection through higher pesticide levels (Haviland and Beers 2012). Similar losses or damage have occurred in Europe; France (2011) 100% cherry in some regions (Weydert 2011); Spain (2011) 100% cherries, 10-40% peaches, 20% strawberries (Colomar et al. 2011); Italy (2012) 50% strawberry (Ginez and Mazollier, 2013) and Italy (2013) 25-30% cherry (Agricoltura Notize).

Female D. suzukii have serrated oviscaps that cut through the fruit skin allowing eggs to be inserted. A single female can lay up to 60 eggs per day and 200–600 eggs in her lifetime randomly distributed on fruits, which develop into larvae. The larvae cut breathing holes and feed turning the fruit flesh brown and soft (Walsh et al. 2011). Further, these damaged areas are open to infection from a range of microbes.

Effective control of this insect pest requires knowledge of ecology and basic population parameters, such as population size, spatial and temporal structure, so as to best and most efficiently employ control options. However, we lack the most basic of information on the population biology of this pest.

We have access to population-level information from collaborations with the East Malling Research Institute, Agricultural and Horticulture Development Board, James Sutton institute (Scotland), and Goettingen (Germany), we will access population-level data concerning the presence of D.suzukii across space and through time. In this short project we will develop simple ways to begin to describe the population structures and dynamics of spotted wing Drosophila using conventional and Bayesian statistical methodologies. This will be essential in developing integrated approaches to developing management for this invasive pest.

This project will complement understanding of fundamental aspects in population biology (Bonsall et al. 2014) and, other ecological work on D. suzukii (Buser et al 2014, Günther et al 2015).