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Heatwave brings a foretaste of global warming as scorpions and banana spiders colonise our shores and ladybirds turn flesh-eating 

Beauty and some not so lovely beasties invade tropical Britain 

By Roger Highfield, Science Editor

SWELTERING temperatures have altered the ecology of the nation: butterflies and moths 
have fluttered in from the Continent; creepie crawlie stowaways are settling down and 
spreading; and the ladybird has developed a taste for flesh.

A report on the impacts of mild winters and hot summers by the Institute of Terrestrial Ecology, Monks Wood, says some plants tended to leaf and flower earlier, animals became active and bred earlier and some species of plants and insects spread northwards.

It will probably take a long freezing winter to restore the natural balance. But it could be a sign of things to come if the greenhouse effect forces world temperatures to rise.

"Warming of the globe is not something that might happen in 50 years; it is happening 
now," said Dr Clive Cummins, scientific coordinator of the Terrestrial Initiative in Global Environmental Research. "There is every reason to believe the sorts of changes we are seeing are symptomatic of larger ones to come."

Wasps: A so-called European "Superwasp", Dolichovespula media, is extending its 
range in Britain. Since it arrived from the Continent during the 1980s, it has colonised 
the South Coast and is now making inroads into the Lake District and Darlington, said 
George Else, the Natural History Museum's entomology expert.

"Dolichovespula media should not be called a killer wasp," he said. "It is a large species, second in size to our native hornet, Vespa crabro; but its sting is no more severe than those of our other wasps and, as far as we know, it hasn't killed anyone."

Two other foreign wasps have also made the most of the weather: the Saxon Wasp, 
Dolichovespula saxonica, which looks very similar to the eight species of indigenous social wasp; and a solitary wasp, Plilanthus triangulum, called a Bee Wolf because females of the species prey on honey bee workers.

"It is not a social species and nests individually in the soil. Until four years ago it was a rarity and found only in East Anglia and the Isle of Wight," said Mr Else. "Now it is all
over South-East England.

Butterflies and moths: Hot weather on the Continent has triggered a population explosion of butterflies and moths, some of which have fluttered across the Channel, such as the Camberwell Beauty that originates in Scandinavia. One was spotted last week in a walled garden in Calder Bridge, Cumbria."It is interesting that the last major influx was in 1976, also a very hot year," said Mr Else.

Other visitors include the European Swallowtail, Clouded Yellow, Painted Lady - from north Africa - and Large White butterflies and the Hummingbird Hawk Moth, Macroglossum stellatarum, so-named because it can be seen hovering over flowers during the day-time.

The number of moth larvae infesting foodstuffs, such as nuts, grains and dried fruit, has increased markedly in the past few years. Clothes moths are also "doing quite well".

Spiders and beetles: Ladybirds have run out of their favourite food, aphids, which boomed during the spring thanks to the mild winter. Large numbers of the beetles have swarmed to the coast, where they cannot migrate any further. "They are looking for food and moisture, and can bite people," said Mr Else.

A black and brown spider, Steatoda noblis, that has repeatedly over the past century been introduced from the Canary Islands with bananas is likely to thrive in these warmer conditions, said Ian Burgess, deputy director of the Medical Entomology Centre in Cambridge.

"Generally speaking they are only found around buildings where they can stay relatively warm in the winter." But the spider has bred successfully in Britain in recent years.

Another newcomer that is spreading is the Wasp Spider, Argiope bruennichi, so named 
for its yellow stripes. The creature has become established along the coast from Dorset to Sussex, after moving in from the south of France, said Paul Hillyard, the NHM's spider expert. "They are quite a nice addition to our fauna," he added. Fleas: "For the flea, this weather is good," said Mr Burgess. "With 12 million cats and six million dogs, there is plenty to feed on."

Scorpions: The southern European scorpion, Euscorpius flavicaudis, probably arrived in 
imported food and is now making a home in southern England. British colonies occur in the most unlikely places, ranging from Ongar Underground station to Pinner, Colchester, Harwich, greenhouses across north London and Sheerness in Kent, where there is a colony of 1,000.

The warmer the weather, the more males seek sex and the more offspring that survive. 
The brown-yellow creature grows to about one inch, but it is unlikely to deliver much of a sting, said Mr Burgess. "It is a delicate, fragile little beastie."

Mosquitoes: Since the concern about global warming, there has been a discussion of the 
possibility of mosquito-borne malaria spreading across northern Europe. The parasite was present in Britain until the Second World War, when wetlands were drained and housing improved.

At least one colony of Anopheles algeriensis, which can carry malaria, is present in Anglesey and could spread, though this north African variety has little contact with humans, said Mr Burgess.

Terrapins: When terrapins grow to the size of dinner plates they are often released into ponds, said Dr Tony Gent, English Nature's reptile and amphibian ecologist. A survey to discover whether they are breeding has been launched by East Sussex Wildlife Rescue.

Of particular concern is Trachemys scripta elegans, the Red Eared Terrapin, which is imported in large numbers. "Viable eggs have been produced in Britain, so the potential is there," said Dr Gent. "Most counties probably have a pond with one or two in it. One Cardiff pond has several hundred."