SWD push & pull

October 2017 – September 2021

Christina Conroy

Christina obtained her BSc and in Animal Behaviour and Welfare and MSc in Entomology from the Harper Adams University.

Drosophila suzukii is the major European horticultural pest threatening the UKs horticultural industry. It was first detected in the UK in 2012 and is the only UK Drosophila species to have a distinctive ovipositor which can oviposit its eggs in ripening fruit. Fruit damage is caused by larvae feeding inside the fruit and secondary infections (e.g. fungus) brought in by the oviposition hole. Crop protection currently relies on the use of multiple insecticide sprays (often broad-spectrum), counter to the aims of DEFRA and the European Commission which advise reducing pesticide usage. Removal of damaged fruit, exclusion netting, and good hygiene practices are also used to reduce D. suzukii pest incidence, but currently, no control strategy can keep D. suzukii under control. A new integrated pest management strategy is therefore required.

In response to reduced temperature and light, the D. suzukii summer morph larvae transitions into the winter morph. The latter has delayed ovary development, larger wings, and increased abdominal melanisation (increasing UV absorption). It is now known that the winter morph infests fruit in the spring. Research has shown that the summer and winter may respond differently in the presence of semiochemicals. A new integrated pest management strategy should, therefore, be adapted to control both morphs.

This PhD project focuses on ‘Developing a ‘push-pull’ strategy for the management of D. suzukii’. Repellents are used to push an insect from the crop and an attractant pulls the insect into a trap.

Research progress

Christina has succesfully defended her thesis in 2022 and is now working for Berry Gardens as a crop protectio specialist.


  1. May 2018: Winner – The Early Researcher Prize
  2. July 2018: Winner – Unleash Your Ingenuity Award
  3. November 2018: Runner Up – Best Poster (AHDB, EMR – Soft Fruit Day)
  4. November 2018: Winner – Best Poster (Berry Gardens Research and Agronomy Conference)
  5. October 2019: Highly Commended Poster (2019 Postgraduate Researcher Excellence Awards)
  6. November 2019: Winner – Best Poster (AHDB, EMR – Soft Fruit Day)
  7. November 2019: Winner – Best Poster (Berry Gardens Research and Agronomy Conference)
  8. February 2020: Winner – RES Student Essay Prize (Royal Entomological Society)
  9. June 2020: The David Miller Travel Award
  10. July 2020: The Worshipful Company of Fruiterers Student Award
  11. January 2021: Second place for the ‘Best Final Year Presentation’ at the AHDB Crops PhD Conference
  12. April 2021: Highly Commended Poster (Postgraduate Researcher Excellence Awards)