Invasive rosemary beetles spread as autumn warms

What's happened

A Guardian Country Diary entry notes rosemary beetles spreading in UK herb borders amid warmer autumns, threatening rosemary, lavender and other Lamiaceae. RHS monitors sightings and urges hand-picking where possible as the invasive species establishes in the UK.

What's behind the headline?

• The beetle’s emergence signals how warming climates allow non-native pests to establish in new regions.
• Hand-picking is recommended, which places responsibility on gardeners rather than chemical controls.
• Focuses on ornamental herb gardens rather than crops, suggesting wider ecological consequences as predators remain scarce.
• The piece highlights a tension between aesthetic gardening and plant health, with practical steps for readers.

How we got here

The Guardian piece describes rosemary beetles, Chrysolina americana, as a Mediterranean species first recorded outdoors in the UK in 1994. The population has grown with warmer autumns, expanding in herb borders and threatening rosemary, lavender and sage. RHS is collecting sightings to monitor spread.

Our analysis

- The Guardian reports on rosemary beetles spreading in UK herb borders as autumn warms. It notes the beetle’s Mediterranean origin and lack of natural UK predators, with RHS monitoring sightings and advising hand-picking where possible. - The Guardian quotes the author and foraging expert about beetle behavior and spread.

Go deeper

• Are rosemary beetles likely to affect other herbs in my garden?
• What signs indicate an infestation beyond leaf damage?
• Should I use insecticides or rely on hand-picking as a control?

More on these topics

• Associated Press - News agency company

  The Associated Press is an American not-for-profit news agency headquartered in New York City. Founded in 1846, it operates as a cooperative, unincorporated association. Its members are U.S. newspapers and broadcasters.

• Long Island - Island in New York State

  Long Island is a densely populated island in the southeast part of the U.S. state of New York, in the northeastern United States.