Join the RHS today and support our charitable work
Free personalised gardening advice
RHS members get reduced ticket prices
RHS members get free access to RHS Gardens
Free entry to RHS members at selected times »
Reduced prices on RHS Garden courses and workshops
020 3176 5800
Mon – Fri | 9am – 5pm
Help us achieve our goals
Join the RHS today and support our charity
The rosemary beetle (Chrysolina americana) originates from southern Europe and has been found in Britain since the mid-1990s. The larvae and adults feed on the foliage of rosemary and related plants.
Rosemary beetle is an insect that eats the foliage and flowers of various aromatic plants, such as rosemary, lavender, sage, thyme and some other related plants.
Rosemary beetle has spread rapidly since first being found breeding in central London in the late 1990s. It is now widespread throughout England and Wales. It is established in Scotland, present in Northern Ireland and may be established in parts of the Republic of Ireland.
Both the adult beetles and the larvae feed on the foliage and flowers of host plants, and are most active between late summer and the spring.
Seen the rosemary beetle? We would like to know.
As part of RHS research we would like to know where the rosemary beetle has been seen.
Please submit your records via our rosemary beetle survey (expected time to complete survey = two minutes).
Submissions to our pest and disease surveys are stored permanently in an anonymised form in order to monitor the spread of the pest or disease. We may contact you within 2 months of your submission in order to verify your sighting but your personal data will not be permanently stored in connection with your submission and will be deleted after 1 year. We publish and share only non-identifiable data from survey submissions (such as a six figure grid reference) with third parties and the public for the purposes of scientific research and advancing understanding among gardeners.
Thank you to everyone who has submitted records – read a blog about the surveys
Watch an animated map of the results from the Rosemary beetle survey (links to YouTube)
Rosemary beetle is fairly easy to spot;
Host plants often survive light infestations without any noticeable adverse affects and so control is usually always necessary.
Hand picking can help to keep beetle numbers below the level at which serious damage occurs. With the taller forms of rosemary and lavender, the beetles and larvae can be collected by tapping or shaking the branches over newspaper spread underneath the plant.
Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)
During mid-summer rosemary beetle can be present on host plants as adult beetles that usually do little or no feeding. In late summer they commence feeding, mating and laying eggs. These hatch after about ten days and both adults and larvae will feed on the foliage throughout autumn to spring during periods of mild weather.
When fully fed, the larvae go into the soil to pupate. Adult rosemary beetles emerge from pupae in the soil in early summer. There is one generation a year but because the adults are long-lived, there can be some overlap between the new and old generations of adult beetles. Because of this, adult beetles can be found at almost any time of year.
Alder leaf beetle
Blue mint beetle
Broad been seed beetle
Chemical labels explained
Chemicals: using a sprayer
Chemicals: using safely and effectively
Citrus and Asian longhorn beetles
Flea beetles on brassicas
Fuchsia flea beetle
Ground beetles and rove beetles
Herbs in containers
Protect your garden
RHS statement on pesticides in horticulture
Willow leaf beetles
the RHS today and get 12 months for the price of 9
RHS members can get exclusive individual advice from the RHS Gardening Advice team.
We're a UK charity established to share the best in gardening. We want to enrich everyone's life through plants, and make the UK a greener and more beautiful place.