🐛

Rosemary Beetle

Chrysolina americana

Not yet photographed by the community

Jewel-like metallic purple-and-green; spreading northward.

Species Profile

Not formally listed; common and widespread species of no conservation concern.

Lifespan: 1–2 years
Size & Weight: 8–11 mm in length
Habitat: Gardens, herb beds, and Mediterranean scrub where rosemary and related aromatic plants grow.
UK Distribution: Found across southern England and Wales, with increasing range northwards; resident year-round in milder regions, though populations may fluctuate seasonally.
Diet: Feeds on the foliage of rosemary, lavender, sage, and other aromatic plants in the Lamiaceae family.
Predators: Ground beetles, spiders, and parasitoid wasps; also preyed upon by birds.
Mating Season: April to October, with peak activity in spring and autumn.
Breeding: Females lay eggs singly or in small clusters on host plants; larvae develop through four instars before pupating in soil; typically one or two generations per year in the UK.
Behaviour: Highly mobile and often seen flying between plants; both adults and larvae feed visibly on foliage, sometimes causing noticeable damage to ornamental herbs. They are most active in warm weather and overwinter as adults in protected sites.

Did You Know?

•The Rosemary Beetle has a distinctive iridescent green and red or purple colouration that varies between individuals and populations.
•It was first recorded in the UK in 1994 in southern England and has since expanded its range northwards, likely due to climate warming and increased cultivation of rosemary as an ornamental plant.
•Both larvae and adults feed on the same host plants, making them capable of causing significant damage to prized rosemary specimens.
•The beetle produces a distinctive smell when handled or threatened, a defensive mechanism common in leaf beetles.
•Heavy infestations can completely strip rosemary plants of foliage, though healthy plants typically recover in the following growing season.

🐛

No photos yet

Be the first to photograph a Rosemary Beetle and share it with the community.