Rosemary beetles feast on lavender, rosemary and sage, but are classified as a pest and if you see one the RHS would like to know
It looks like a sparkly ladybird – but despite its gorgeous glittery appearance the rosemary beetle has the potential to wreak havoc in gardens.
The insect – classified as a pest by the Royal Horticultural Society – emerges from the soil in early summer and enjoys feasting on many common garden plants.
Rosemary – from where the beetle takes its name – sage, thyme and lavender are all among its target foods, with some reports suggesting that larger numbers of the beetle would have the power – and the appetite – to strip entire bushes and plants bare.
The beetle originates in southern Europe and was first spotted in small numbers in the UK in the late Nineties and early 2000s.
In 2008 the RHS set up a survey to track the spread of the species because of the significant amounts of damage this non-native can cause.
Fast forward more than a decade and the RHS says the beetle has now become more widespread across the country and is continuing to crawl into all parts of the UK.
While the beetle has become more common among garden wildlife, the organisation continues to monitor its takeover and receives large numbers of records every year from people who head to its website to enter information they have gathered from their own gardens.
An RHS spokesman explained: "As well as engaging gardeners to discover and report what is in their garden this has helped us to provide accurate advice about the spread of the beetle and information on where it occurs.
"In future such data could potentially be investigated further to study rates of spread, effects of climate change (range shifts) and potentially more."
Adult beetles reportedly begin rapid feeding from late summer, ahead of laying their eggs which they leave on the underside of leaves. In the last few weeks, gardeners have started turning to social media to report sightings of the beetle.
Facebook gardening groups – and even some amateur photography groups captivated with their sparkly appearance – have posts from people asking what they are, how best to control them and sharing photographs of their colourful appearance.
One gardener asking for advice pleaded: "My rosemary and my sage have got rosemary beetle. They have chomped both plants to shreds. Gardening friends, do I chunk the plants out and start again?" while another wrote: "For something that looks so awesome and isn't much bigger than a ladybird these beetles do a lot of damage...this was found on the lavender this morning...and it's not going back there."
The RHS website has its own advice for those needing to control an outbreak of rosemary beetle.
In most cases, it says the host plant will survive without many noticeable affects, but close and careful monitoring is advised to spot damage before it can't be reversed.
It reads: "Check susceptible plants frequently so action can be taken before a damaging population has developed."
If the beetles can't be tolerated suggestions include removing individual insects by hand, picking them from affected plants, or with taller branches the beetles and its larvae can be collected by tapping or shaking branches and collecting the insects which drop on newspaper spread underneath.
Encouraging wildlife in the garden such as birds, frogs and predatory ground beetles who will eat the beetles and their offspring, is also said to be successful method for tackling a population getting out of control.
Gardeners who find rosemary beetles among their plants this summer can report their findings here. More advice for controlling an outbreak can be found on the RHS website.