Rosemary Leaf Beetle

Rosemary Leaf Beetle on Lavender (A new invaded to Ireland) © Barbara Graham

The Rosemary Leaf Beetle Chrysolima Americana is a small purple-striped green beetle, 8mm long that live on aromatic herbs such as Sage, Thyme, Lavender and of course Rosemary from which it gets the name. They originate from Southern Europe and were first detected in Britain in the mid 1990’s.

Up to last Wednesday 20th June 2012, these colourful little invaders were never recorded in Ireland.  Barbara Graham a keen outdoor enthusiast was taking photographs in the garden of her apartment complex in North Dublin City, when she noticed a very colourful little beetle munching at the Lavender plants.  She ran off numerous shots of at least 30 of these Rosemary Beetles, even mating couples.  While researching later on the internet, Barbara realized that these beetles were unusual to Ireland.  Two sample specimens were taken and sent to Cork for verification with the positive ID being returned that these were definitely Rosemary Leaf Beetles and probably the first ever recorded in the country.

Rosemary Leaf Beetle  © Barbara Graham

Rosemary Beetles are considered a pest and congregate among the leaves of herbs, which they feed on. The beetles lay elongated eggs beneath the leaves from September and continue to do so on warm days right through the winter. These hatch after a couple of weeks and the larvae feed on the plants for about three weeks before entering the soil to pupate. Two weeks later the adults emerge and continue munching through the leaves and laying their eggs to kick start the cycle once more.  Please let Invasive Species Ireland (http://invasivespeciesireland.com/) know if you have encountered these destinctive bugs in your garden.

John N Murphy