One of these, a recent Defra Horticulture LINK project led by East Malling Research, highlighted good crop hygiene, early introduction of large numbers of predatory mites (Neoseiulus cucumeris) and the use of blue roller traps positioned along polythene tunnel legs as important methods for gaining control.
In an additional study in 2014, HDC-funded entomologist Clare Sampson of the University of Keele surveyed strawberry-producing businesses that are failing to gain adequate control of WFT and compared them with businesses that are successfully controlling the pest.
The results showed that control was most successful on one-year-old crops where well-maintained regular predator release strategies were employed from or before first flower, using N. cucumeris combined with Stratiolaelaps scimitus (formerly Hypoaspis miles) and/or Orius species and blue sticky roller traps. In each case, crop-protection spray programmes that are harmful to predators were avoided.
Control was found to break down where there was a large carry-over of thrips from the previous season, predators were released too late, insufficient N. cucumeris were released early in the season and crop-protection products that harm predators were used when predatory mites were being released or during their establishment.
The full project report can be found on the publication page of the soft-fruit section of the HDC website.
Horticultural Development Company
For details on all HDC activity, visit www.hdc.org.uk