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Exploiting knowledge of western flower thrips behaviour to improve efficacy of biological control measures - HH3102TPC

The main objective of the proposed research is to reduce the use of chemical pesticides against western flower thrips (WFT) on protected horticultural crops, by exploiting new knowledge of WFT behaviour to improve the efficacy of novel biological control strategies. WFT is a major pest of both ornamental and edible protected crops, causing direct damage which reduces plant quality, marketability and yield, and acting as a vector for the very damaging tospoviruses, Tomato spotted wilt virus (TSWV) and Impatiens necrotic spot virus (INSV). Most growers of WFT-susceptible edible crops, and an increasing proportion of growers of protected ornamental plants now use biological control methods for WFT, within Integrated Pest Management (IPM) programmes. However, the majority of growers of ornamental crops still rely on pesticides for the control of WFT, and those growers using biological control methods on both ornamental and certain edible crops still need to use supplementary pesticides against thrips.

The novel approach to WFT control in this research aims to develop more effective strategies for using microbiological control agents as alternatives to chemical pesticides. The research will address DEFRA’s policy objectives of minimising the use of pesticides and promoting sustainable, adaptable and cost-effective horticultural production methods which meet consumer requirements for a safe food supply chain and environmentally-responsible growing systems. Underpinning research on the behaviour and activity patterns of WFT will identify where and when the microbiological control agents should be applied for most effective control. Strategic research on using improved knowledge of WFT behaviour and chemical ecology will aim to manipulate the activity of WFT with semiochemicals or with adapted cultural practices for increased contact and infection rates by the biological control agents. The results will allow practical methods to be developed for improved, more cost-effective control.

The microbiological control agents used in the research will be entomopathogenic nematodes and fungal pathogens. Pot chrysanthemums and cucumber will be used as contrasting representative host crops for WFT but the strategic approaches taken will allow the results to be potentially applicable to other horticultural crops. The research results will be applicable to other pests and natural enemies, because both microbiological control agents are known to be effective against pests other than WFT, and compatibility of the nematodes, fungal pathogen and semiochemicals with other biological control agents used in IPM will be determined.
1. To determine the spatial and temporal distribution and activity patterns of WFT on two contrasting crops, in order to identify the most effective hours and placement for applications of microbiological control agents to reach the target life stages (ADAS and Keele).

2. To quantify the efficacy and persistence of Steinernema feltiae and Beauveria bassiana against all WFT life stages on selected host plant material and growing media (ADAS and HRI).

3. To determine whether the efficacy of S. feltiae and B. bassiana can be improved by manipulating WFT behaviour with semiochemicals or by adapting use of glasshouse lighting (ADAS, IACR, Keele and HRI).

4. To quantify the effects of S. feltiae, B. bassiana and semiochemicals on other selected biological control agents used in IPM on protected crops (ADAS, HRI and IACR).
Project Documents
• Final Report : Exploiting knowledge of western flower thrips behaviour to improve efficacy of biological control measures   (937k)
Time-Scale and Cost
From: 2002

To: 2006

Cost: £499,724
Contractor / Funded Organisations
Pest Control              
Protected Cropping              
Sustainable Farming and Food              
Sustainable Production              
Fields of Study