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Biocontrol of cabbage root fly by release of predators. - HH1830SFV

The predatory staphylinid beetle Aleochara bilineata will be released inundatively to determine whether biological control of a pest species using a predator can be achieved under field conditions in the UK. This predator has been chosen as the vanguard for this approach, as it develops as a parasitoid of the cabbage root fly, and so has a finely tuned system for locating this specific pest under field condotions. As this rove beetle is highly-active and flies readily, it should spread paridly through fly infested crops. While this mobility is an advantage provided conditions within the crop remain favourable, the predators may not take long to emigrate from the release fields should conditions become unfavourable. Therefore, a substantial part of the propsed project will be to study in detail all aspects of the dispersal/dispersion of the prdators and in particular the interaction between insect movements and the stimuli required to prevent the released predators from leaving fly-infested plants. Results from an earlier MAFF-funded project (HH1815SFV) indicated that under semi-field conditions (covered crops) low numbers (2/plant) of this predator gave good control of fly larvae on the roots of artificially infested Brassica plants. The current project will concentrate on taking the research to the next stage to determine whether control of fly larvae can be achieved in the open-field when the dispersal of the predators is not restricted and when the pest infection is not distributed regularly through the crop but varies widely from plant to plant. Work will be done to quantify how insecticide sprays, applied against other target species, affects predator numbers and how the released predators intreact with the wide range of other invertibares found in brassica crops. The overall aims are to show whether field infectations of the cabbage root fly can be controlled by inundatively releasing a predatory insect and to describe the impact that such releases could have on the biodiversity found in cultivated fields.
To identify the biological criteria that must be satisfied for biological control, involving the release of a predatory insect to control a pest species, to be successful under field conditions.
Project Documents
• Final Report : Biocontrol of cabbage root fly by release of predators.   (212k)
Time-Scale and Cost
From: 1999

To: 2002

Cost: £306,671
Contractor / Funded Organisations
Horticulture Research International
Biological Control              
Crop Pests              
Fields of Study