Unwelcome insect tourists who love the British weather

THE warm, damp weather hasn’t been much to write home about recently.

But while it seems like it’s just another disappointing British summer, the conditions – particularly down south – have been ideal for mosquitoes.

The unusually warm spring, followed by a damp June and July has created a longer breeding season for insects. According to NHS Direct statistics, there were 9,654 calls about bites and stings between May 2 and August 21 this year, up from 8,244 calls for the comparable period last year – a rise of 17 per cent.

Not all these bite complaints are due to mosquitoes – they could be attributed to bedbugs, midges and other insects, but anecdotal evidence suggests their numbers are increasing.

It’s difficult to record accurately mosquito numbers in the UK, but the authorities are trying to do just that. The Health Protection Agency (HPA) has organised the Mosquito Recording Scheme to look into where and how mosquitoes live and breed.

Meanwhile, the Chartered Institute of Environmental Health, with help from the HPA, has created Mosquito Watch, a voluntary reporting system geared towards collecting and analysing various specimens.

There are an estimated 33 species of mosquito in the UK, most of which – apart from bothering people as they try to enjoy their picnics – aren’t a major health risk. Problems only tend to arise when Britons travel to countries with malaria, dengue or other mosquito-borne diseases.

Malaria in England had effectively been eradicated by the 1950s, largely due to the draining of much of the marshland where mosquitoes bred. But with the growth of global travel there are now around 2,000 cases a year of the disease in the UK. In many cases mosquitoes have been found on aircraft, or in luggage, from countries where the disease is prevalent. On rare occasions, people may have even contracted malaria in Europe and North America, so-called “airport malaria”.

Richard Moseley, technical manager with the British Pest Control Association (BPCA), says mosquitoes appear to have become more prevalent in the UK recently.

“We are aware that they appear to have cropped up in the UK more frequently and the warm, damp conditions are perfect conditions for mosquito breeding.

“Insects are weather-dependent and the longer you have these conditions the more likely they are to breed in larger numbers.”

Mosquito can be bothersome, but in this country – unlike many in the tropics – they aren’t a matter of life or death. However, there are some potentially dangerous species getting closer to our shores. The Asian Tiger mosquito, known for its white and black striped pattern, has been found in parts of Italy and southern Germany and has reportedly been spotted in Belgium.

Although it doesn’t carry malaria, it does transmit West Nile virus, Yellow Fever and dengue.

So should we be worried? “We should always be concerned by the potential arrival of non-native species, and we do appear to have more mosquito activity,” says Moseley. “With climate change, we have to accept that our climate may become more suitable for insects that would not have survived here previously, and they might bring problems we haven’t had to deal with in the past.”

Dr James Logan, lecturer in medical entomology at the London School of Hygiene and Tropical Medicine, says although we have mosquitoes in this country, including potential malaria-carrying species, there is no proof they have grown in numbers. “We have anecdotes that people are getting bitten more but there is no firm scientific evidence to support this,” he says.

Dr Logan, who is also a Fellow of the Royal Entomological Society, believes the dangers posed by mosquitoes in the UK are relatively small.

“There is some evidence that climate change could support more of these mosquitos in the future and we are keeping an eye on this. But it’s important to remember that Malaria was endemic in the UK during the ‘50s but we got rid of it because we have such a good health system,” he says.

“We do have mosquitos here that are capable of carrying the disease and we do have people coming into the country with malaria, but we don’t have the big outbreaks they have in the tropics because we have the resources to deal with it.”

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For more advice about bites and stings visit www.nhs.uk/nhsdirect