Alternatives needed to control diamondback moth as pyrethroid resistance grows

The need for alternative strategies to control diamondback moth (Plutella xylostella, DBM) has been highlighted by a new Rothamsted Research study which found three geographically separate samples were all resistant to pyrethroid insecticides.

Image: Christian Guthier (CC BY 2.0)
Image: Christian Guthier (CC BY 2.0)

The samples of DBM caterpillars were taken from brassica crops in Lincolnshire, Suffolk and Scotland.

Research leader Dr Steve Foster said: "Pyrethroids are normally the first choice of insecticides against moth pests but these tests indicate that resistance is present in the DBM population over a wide geographical spread."

He added: "If growers continue to use pyrethroids, this could be doubly damaging – not only would it not have an effect on DBM, it would be killing beneficial insects which attack DBM."

Foster will present his findings at an AHDB Horticulture workshop at PGRO near Peterborough on 24 January, which will provide the industry with an opportunity to discuss the implications of these on future pest management.

Pyrethroid resistance was first confirmed in one DBM sample from Lincolnshire in August. AHDB worked together with industry to produce an emergency 120-day authorisation for Benevia 10OD for use as an insecticide on a range of Brassica crops for DBM control.

"The Benevia approval meant growers had a product available that would work well alongside products containing spinosad as an active ingredient, but it does not currently have full label recommendation from the Chemical Regulation Directorate," Foster explained.

Have you registered with us yet?

Register now to enjoy more articles and free email bulletins

Sign up now
Already registered?
Sign in

Before commenting please read our rules for commenting on articles.

If you see a comment you find offensive, you can flag it as inappropriate. In the top right-hand corner of an individual comment, you will see 'flag as inappropriate'. Clicking this prompts us to review the comment. For further information see our rules for commenting on articles.

comments powered by Disqus

Read These Next

Pest & Disease Factsheet - Mealybugs

Pest & Disease Factsheet - Mealybugs

Vines, tomatoes and tropical plants are among those at risk.

Pest & Disease Factsheet - Bacterial and fungal canker

Pest & Disease Factsheet - Bacterial and fungal canker

A wide range of nursery stock can be susceptible to potential damage from various cankers.

Pest & Disease Factsheet - Spider mites

Pest & Disease Factsheet - Spider mites

Defences for protected and outdoor ornamentals.