Slugs and snails retake top spot of most bothersome garden pests

Common garden slug slithers along a leaf in close up macro photo
Common garden slug slithers along a leaf in close up macro photo

Slugs and snails have returned to the top of a gardeners' pest list for the last year as people spent more time on green-fingered activities in the coronavirus lockdown.

The gastropods, a perennial foe for many garden owners, knocked the invasive box tree caterpillar off the top spot.

It is the first time they claimed first since 2017, and comes amid reports of damage to crops of potatoes and beans.

Vine weevils were ranked second in the Royal Horticultural Society's (RHS) list, which surveyed gardeners.

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Slug in the garden eating a lettuce leaf. Snail invasion in the garden
Slug in the garden eating a lettuce leaf. Snail invasion in the garden

The box tree caterpillar, which strips box plants of their leaves, tumbled to third place for 2020 as reports of the species fell by 40%.

Its spread has slowed down after rapidly growing in Northern England and Wales, the RHS said.

The society added its gardening advice service saw an 88% increase in pest and disease enquiries throughout 2020 as people spent more time in the garden during lockdown and social distancing restrictions.

Rounding off the top five pests were ants and the woolly aphid.

In order, the rest of the top 10 was the glasshouse red spider mite. the fuchsia gall mite, glasshouse thrips, the rosy apple aphid and the capsid bug and glasshouse mealybug.

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A pretty Box Tree moth Caterpillar (Cydalima perspectalis) feeding on a box bush in the UK.
A pretty Box Tree moth Caterpillar (Cydalima perspectalis) feeding on a box bush in the UK.
Ant drinking water on leaf of laurel, Woking, Surrey, UK.
Ant drinking water on leaf of laurel, Woking, Surrey, UK.

Andrew Salisbury, principal entomologist at the RHS, said: "The pests and diseases that gardeners commonly face on their plots has fluctuated over the last 25 years but some age-old problems persist.

"With gardens taking on a more important role in supporting wellbeing and the environment it's important that research into management and mitigation of them continues and our rankings help inform this focus.

"It’s also imperative that we continue to anticipate future threats such as the disease Xylella, which is already present in Europe, and the Marmorated stink bug, to protect our gardens for the future."

The top garden diseases reported in 2020 were: Honey fungus, pear rust, leaf spot and canker of Prunus, rose black spot, bracket fungi, powdery mildew of Prunus, blossom wilt of fruit trees, phytophthora root rots, rose powdery mildew and brown rot of fruit.

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