Defra - Department for Environment, Food and Rural Affairs.

Science Search

Science and Research Projects

Return to Science Search homepage   Return to Project List

Improved biological control of western flower thrips on chrysanthemums. - HH1838SPC

The main objective of the research is to identify and evaluate new methods to facilitate the development of improved strategies for biological control of thrips on protected chrysanthemums, to reduce the current reliance on pesticides, which is consistent with MAFF Policy objectives. The research will focus on the biology and control of western flower thrips, Frankliniella occidentalis (WFT), which is the main pest of protected chrysanthemums and the target of most pesticide usage on both pot and cut flower crops. Strategic research on the chemical ecology of the interactions involved within the host plant, pest and natural enemy complex will aim to identify plant semiochemicals which repel WFT from susceptible host cultivars and attract them to 'lure' plants where supplementary thrips predators, currently not used against WFT on ornamentals, can be targetted for improved, cost-effective control. This 'push-pull' strategy, together with underpinning research on the biology of WFT and its natural enemies on selected chrysanthemum cultivars, offers a novel approach to the development of sustainable non-chemical pest control systems for chrysanthemums. Pot chrysanthemums will be used as a model crop for the research, using cultivars at growth stages attractive to WFT as 'lure' plants. The development of robust biological control strategies for the control of thrips on chrysanthemums will lead to commercial uptake of Integrated Pest Management (IPM) on a crop which is currently treated with routine intensive pesticide programmes. The protected chrysanthemums industry will benefit from the research by having the opportunity for production of improved quality plants grown with sustainable, non-chemical, cost-effective pest control methods, which will enable UK growers to respond to the increasing demand for environmentally-friendly production techniques and reduced pesticide inputs, thus competing more effectively in world markets.
1. Identify a pot chrysanthemum cultivar which attracts WFT and which could be used as a `lure` plant, identify the role of the plant volatiles in that attraction and determine whether the host plant and volatiles also attract flying adult predators Orius laevigatus (ADAS and IACR).

2. Investigate the responses of WFT to non-host plant species and if repellent, identify the role of plant volatiles in that repellency and evaluate their effect on Orius laevigatus (IACR).

3. Quantify the spatial distribution of WFT adults, larvae and pupae on the selected `lure` chrysanthemum cultivar. (ADAS)

4. Quantify the establishment of Orius laevigatus and its searching ability and predation rate on WFT adults and larvae on the selected `lure` chrysanthemum cultivar. (ADAS)

5. Quantify the searching ability and predation rate of Chrysoperla carnea larvae on WFT adults and larvae on the selected `lure` chrysanthemum cultivar. (ADAS)

6. Quantify the searching ability and predation rate of Hypoaspis spp. on WFT pupae in compost and on capillary matting. (ADAS)

7. Evaluate methods for manipulating WFT behaviour and for improving biological control strategies. (ADAS and IACR)

8. Develop a formulation of the thrips antifeedant appropriate for use in the modified push-pull strategy.

9. Quantify the reduction of WFT numbers on ‘Swingtime’ plants by Hypoaspis miles over at least an 8-week period.

10. Quantify the reduction of WFT numbers on ‘Swingtime’ plants by a strategically-timed application of Steinernema feltiae.

11. Determine the efficacy of the modified push-pull strategy, combining the use of thrips attractant, antifeedant and multiple natural enemies.

Project Documents
• Final Report : final report   (162k)
• Final Report - Annex : annex 2   (524k)
• Final Report - Annex : annex 3   (602k)
• Final Report - Annex : report annex 1   (1161k)
Time-Scale and Cost
From: 1998

To: 2002

Cost: £249,466
Contractor / Funded Organisations
Biological Control              
Organic Farming              
Pest Control              
Fields of Study