A decade of sighting recorded by the public as part of the UK Ladybird Survey since 2005 has declared Harlequin ladybirds as the UK’s fastest invading species, reaching almost every corner of the country in just 10 years.

In a paper, published in the journal Ecological Entomology, Dr Roy and co-author Peter Brown, of Anglia Ruskin University, stated that the harlequin ladybird “has provided unique and detailed insights into invasion biology and such surveillance is critical to strategies for early-warning and rapid response”.

Dr Roy explained that the monitoring scheme has helped scientists to better understand the routes that alien species use to invade and how it might be possible to reduce the threat. The researchers have thanked the public for contributing thousands of sightings of ladybirds as part of the monitoring programme and for helping to create an invaluable dataset for large-scale and long-term research.

The harlequin ladybird, officially known as Harmonia axyridis, feeds on native ladybirds. The harlequins were first discovered in Britain in 2003, spotted in Essex and have since then spread as far as the tip of Cornwall and the Shetland Islands.

Dr Roy, asserted,” The harlequin is the fastest-spreading alien species on record that I can think of. It is now consolidating its presence in the UK”. It is reported that the Grey squirrels, American mink, ring-necked parakeets and muntjac deer are advancing at a rate far behind these harlequins.

These cannibalistic ladybirds are believed to be responsible for the decline of at least seven native ladybirds, recording a 44% decline in 2012. On a brighter note, Harlequins prey on a variety of smaller insects, especially aphids which can damage crops and garden flowers. Additionally, the number and proliferation of the native insects is kept in check by the harlequin.