Horse chestnut scale insect

Time to act:

Jun, Jul, Aug, May, Sep

The horse chestnut scale insect was first found in the UK in the late 1960s, having come over from southern Europe. It is now widespread and common in the south of the UK and Ireland, and is spreading northwards. Mature, adult horse chestnut scale insects are up to 5mm long and can be found on the main trunk and branches. They drop off in summer, leaving white clusters of eggs.

Symptoms

Little damage is done to the host plant, but the insects can look unsightly. They suck sap from plants and produce honeydew, which can encourage sooty mould to develop. It's more of a problem in urban areas where temperatures are higher.

Find it on

horse chestnuts, magnolias, cornus, bay, lime and acer trees.

Advertisement

Organic

Scrape the eggs off by hand and move them to an alternative tree, or destroy them.

Chemical

Spray with an insecticide containing deltamethrin in midsummer.

Advertisement

Discover more ideas and inspiration

Related content

Aphids

Apple sawfly

Codling moth

Elephant hawk moth

Related offers

SAVE 10%

Subscriber only content

Save at Plants Galore

Save 10% on your shopping at Plants Galore, choosing from their great range of plants, as well as garden furniture, planters, wildlife accessories and more.

Unlock now

SAVE 20%

Subscriber only content

Save 20% at Hayloft

Hayloft is offering BBC Gardeners’ World Magazine subscribers an exclusive 20% discount across its entire range, from hardy perennials to evergreen and deciduous shrubs.

Unlock now

FREE P&P

Buy 1 get 1 free on acers

Buy one acer at Thompson & Morgan and you'll get another one free. Plus, there's also free p&p with this offer.

Use code: already applied

Order now