AN ALIEN invader has arrived in Wharfedale and could wipe out the native population.

But unlike the curious being famously captured on film on Ilkley Moor 25 years ago, an extra-terrestrial origin has been ruled out for the latest creature to land, and it is not associated with mysterious spacecraft.

The first reported sightings in Wharfedale of voracious non-native Harlequin Ladybirds came from Otley last summer.

Now it is believed the invader has spread west along the valley to Ilkley.

An unusual ladybird photographed in the Gazette's offices was identified by Wharfedale Naturalists' Society as almost certainly' a Harle-quin.

British naturalists are keeping a close eye on the spread of the Asian species around the country as it eats the eggs and larvae of other ladybirds and butterflies, harming the population of these species.

The Harlequin is usually bigger than native ladybird species, and can vary greatly in colour and pattern.

It is more hardy than native ladybirds, and more likely to be found out and about in the winter months, often getting into houses. It feeds mainly on aphids, regarded as a garden pest, but when food supplies are short it will eat the eggs and larvae of other creatures.

Anne Riley, of Wharfedale Naturalists' Society, said: "It is predicted to spread to most parts of the UK in a few years.

"It has been described as the most invasive ladybird species on Earth and poses a series threat to biodiversity.

"It is a large and voracious species and has the potential to out-compete native ladybirds and other insects for food."

The Harlequin Ladybird was introduced to North America in 1988, and has since become the most widespread ladybird species there.

It was first seen in Britain in summer 2004, and has steadily spread out from the south east of England, reaching the Midlands and Yorkshire.

It can also reproduce continuously through spring, summer and autumn, boosting its population ahead of native ladybirds.

Sightings and photographs of Harlequin ladybirds can be reported to The Harlequin Ladybird Survey researchers online at (www.harlequin-survey.org).