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Improved viral bioinsecticides for the control of apple pests. - HH1834STF

Growers are under considerable pressure to reduce pesticide residues on food resulting in a need to develop alternative environmentally friendly strategies which are at the same time more competitive with chemical insecticides. Factors such as development of insecticide resistance and other environmental issues may compensate for any differences in production costs of viral and chemical insecticides. The main objective is to investigate and /or evaluate pathogenic viruses from four important UK pests on apples for the production of improved viral insecticides. In the case of the codling moth (where insecticide resistance has already developed in Europe) an improved Cydia pomonella granulovirus lacking EGT (ecdysteroid UDP-glucosyl transferase), produced in the last MAFF funded project (HH1823S), will be evaluated on apples. A new recombinant CpGV expressing a toxin from the itch mite Pyemotes tritici will also be produced and evaluated using a diet-based bioassay. In recent years the summer fruit tortrix (Adoxophyes orana) has also become an important UK pest and A. orana virus isolates collected in the UK will be purified, characterised and evaluated for the control of this pest. In addition, there will be a new initiative to isolate viruses from rosy apple aphid and apple sawfly. The knowledge gained should provide a realistic foundation for the assessment of the commercial potential of at least two of these viruses which will help the UK growers and supports the MAFF policy objective which aims to ensure that UK growers can respond to the increasing pressure to reduce pesticide usage.

To investigate and/or evaluate pathogenic viruses from four important UK pests on apples for the production of improved viral insecticides.

The main objective is the development of components of an IPM programme for the control of four major pests of orchards using insect viruses.

1.Produce a recombinant Cydia pomonella granulovirus with a faster speed of kill compared to wild type virus.
2. Isolate and characterise baculoviruses found in Adoxophyes orana in the UK.
3.Isolation and subsequent characterisation of viruses isolated from apple sawfly and rosy apple aphid.

The three objectives are not interdependent

Objective 1 is directed towards the development of a detached apple based bioassay to compare the efficacy of CpGV-M1 and CpGV EGT- in reducing apple damage. This is an artificial situation and discounts possible behavioral effects resulting from the different viral infections e.g. possible differences in the efficiency with which the larvae are able to target the apples in the presence of foliage or their preference for foliar feeding. Depending on the outcome of the apple bioassays, it may be necessary to include some bioassays on small apple trees for a more appropriate comparison in order to confirm the validity of the simpler bioassay.
Objective 3 encompasses a new area of research and as a result the outcome is unpredictable. Initially virus extraction will be performed on field collected specimens of the insects, however, it may be necessary to try and establish temporary colonies of these insects to produce sufficient numbers of insects.
Project Documents
• Final Report : final report   (2749k)
Time-Scale and Cost
From: 1999

To: 2003

Cost: £531,379
Contractor / Funded Organisations
Horticulture Research International
Biological Control              
Organic Farming              
Pest Control              
Fields of Study