BACKGROUND

Blackberry leaf midge, Dasineura plicatrix, has recently developed as a serious pest of blackberry and has now spread to raspberry in the UK and elsewhere in Europe. It attacks the shoot tips killing out the terminals, stunting growth and causing branching. Growers consider that it significantly affects yield in both crops, and they currently have no method of predicting or monitoring the severity of attacks or of timing application of control measures if necessary.

OBJECTIVES

This project aims to complete work on identification of the female sex pheromone of D. plicatrix started under HDC studentship CP38. The two components of the pheromone will be fully identified and synthesised. The pheromone blend will be optimised for attraction of male midges in field tests and the resulting traps and lures made available to growers for evaluation. Effective monitoring of this pest will contribute to HDC project SF102 on the biology and integrated control of blackberry leaf midge on blackberry and raspberry.

RESULTS

• During 2010 the chemical structures of the two components of the female sex pheromone of the blackberry leaf midge have been identified and their stereochemistry determined.
• Lures containing the two synthesised components attract male D. plicatrix to traps; the single components are virtually unattractive.
• During 2011 the potential of the traps for monitoring populations of D. plicatrix and the damage caused will be investigated.