PC/SF 276 - Pheromone technology for management of capsid pests to reduce pesticide use in horticultural crops (HortLINK)

Summary/Findings: Capsid bugs are important pests of several high-value horticultural crops in the UK and many more worldwide.  In the UK, the common green capsid, Lygocoris pabulinus, and the European tarnished plant bug, Lygus rugulipennis are the most important species.  L. pabulinus, traditionally a pest of apples, pears and blackcurrants is an increasingly important pest of strawberries, blackberries and raspberries.  L. rugulipennis is an important pest of late season strawberries and of various glasshouse salad crops, notably cucumber.

• Crop invasion by capsids is sporadic and unpredictable, and, in the absence of effective control measures, capsid bugs cause severe economic losses. They cause damage at low population densities and are difficult to detect at such levels in normal crop inspections.
• Without accurate monitoring information, growers are forced to use remedial applications of broad spectrum insecticides. Although these treatments can be effective against capsids, they disrupt the biological control of other pests and can lead to the application of further sprays.  The recent outbreaks of pesticide-resistant western flower thrips on strawberry are probably due, at least in part, to routine spraying against capsids.
• The need to use broad spectrum insecticides for control of capsid bugs is a major bottleneck to the implementation of IPM and the quest towards pesticide-free foods.
• Effective monitoring systems for capsid pests would help to ensure that pesticides are only used where necessary, so reducing routine applications of broad-spectrum pesticides that disrupt IPM of these and other pests. They would also enable the use of more selective insecticides and biological approaches for which timing of sprays is critical.

The purpose of this project is to reduce use of broad-spectrum insecticides against capsid pests on a range of horticultural crops and to maintain or improve the level of control in both conventional and organic crops.  This will be achieved by building on previous research at EMR and NRI to develop effective and practical pheromone lures for monitoring three species of capsids.  Achievement of this will provide means to reduce substantially the need for prophylactic applications of broad-spectrum pesticides in several horticultural crops and encourage rational use of more specific approaches to control capsid pests and increase productivity. 

Objectives:

• To confirm identification of components of the female sex pheromones of pabulinus.
• To identify components of the female sex pheromone of tripustulatus.
• To determine factors affecting attraction of rugulipennis, L. pabulinus and L. tripustulatus to synthetic pheromone lures in laboratory and field. 
• To investigate the possibility of synergising the attractiveness of the pheromones of the three species with host plant volatiles in laboratory and field.
• To develop practical pheromone lures and traps for rugulipennis, L. pabulinus and L. tripustulatus.
• To calibrate pheromone traps for monitoring capsid pests in at least two field crops and one protected crop.

Project extension objectives:

• Improve and test the lure for rugulipennis so that it is long lasting and practical for use by growers
• Calibrate the trap for rugulipennis for use in pest monitoring to establish a treatment threshold for its use in late season strawberry and/or cucumber
• Develop an effective lure and trap for pabulinus with associated data for pest monitoring
• Encourage commercial production of traps and lures and produce grower information sheets on the use of the traps for monitoring capsids