The seven spot and the two spot, which until recently were common, are under threat along with the rarer five spot. Charity Buglife wants the government to do more to protect these UK varieties. They say that everyone should be vigilant for the species and record where it is. The Peterborough-based charity, also known as the Invertebrate Conservation Trust, says the harlequin also damages crops by eating fruit.
A survey was launched at London's National History Museum in March 2005 to track the spread of the voracious predator known to easily out-compete home bugs for food. Wildlife enthusiasts were asked to monitor their gardens for the harlequin which is black and red or orange and black.
How To Spot The Harlequin
* Tends to be rounder in shape than most UK native species
* About 5-8mm in size - similar to the common seven spot
* It has a white plate with a big black M-shaped marking on it, just behind the head
* Sighted bugs can be orange with between 15 and 20 spots
* Others may be black with two orange or red spots
* Some also seen to be black with four orange or red spots
Buglife director Matt Shardlow said at the time: ‘The harlequin may sound like a bit of a jester but there is nothing funny about it at all. There're a whole lot of problems it will bring with it. It out-competes native species and eats them. Everyone should be vigilant for the species and record where it is.’
The insect - originally from south-east Asia - has a huge appetite for greenfly, leaving little for native ladybirds who then starve. Worse still, organisers of the survey said, the harlequin would turn on other ladybirds if food resources diminished for the whole population. The invader will also prey on other types of insects, eating butterfly eggs, caterpillars and lacewing larvae.
Freelance insect expert Richard 'Bugman' Jones, who is based in East Dulwich, south London, told The-Latest : 'Eventhough the harlequin is only a tiny little beast it will get out of control in Britain because it will eat our native ladybird which will therefore become extinct.'
In January the government launched a massive cull of grey squirrels across England to try to halt declining numbers of the endangered native red population.
Minister Jim Knight said "humane and targeted pest control" would cull greys over the next three years in areas where red squirrels are being 'squeezed out'. Most UK reds are confined to Scotland, Cumbria, Northumbria, the Isle of Wight and islands in Poole Harbour.
They are weaker than grey squirrels, which also carry the squirrelpox virus. Mr Knight said the aim was not to completely eradicate the greys, which have a population estimated at more than two million - outnumbering red squirrels by 66 to one.
Grey squirrels were introduced to Britain from North America in the 19th Century and have thrived in lowland areas. But the European Squirrel Initiative, which campaigns for the protection of the red squirrel, called for more effective ways of controlling the grey population.
It said drugs should be considered to sterilise the greys. Despite the Americanisation of the name to "ladybug", ladybirds are actually beetles. Ladybirds are considered a sign of good luck in many cultures, and killing one is believed to bring misfortune. This may go back to a time when people first realised that lots of ladybirds around meant it would be a good season for growing food.
They might look cute, but ladybirds were found by early Australian farmers to be lethal killers ‚ of crop pests, that is. One such predator is a ladybird known as the mealybug ladybird, Cryptolaemus montroutizieri. These lay their eggs in the egg masses of common pest insects such as mealybugs. When the larval ladybirds hatch out, they immediately set about eating the mealybug eggs. As adults, ladybirds will also feed on both eggs and larvae of these pests.
Ladybirds are even being used to control insect pests in eucalypt plantations. They feed on the immature stage of the Eucalyptus leaf beetle. The results suggest tree plantations could benefit from the release of ladybirds early in the season when pests are laying eggs.