Just as it seemed that this wet summer couldn’t get any worse, an explosion of biting, stinging pests is on the way. Although the weather was a washout for us, it was bliss for many insects.

Mosquitoes have been breeding in rainwater that has collected in buckets, pots and children’s toys left out in the wet weather. The result is an upsurge in itchy, inflamed bites. The NHS Direct helpline has reported a rise in the number of calls relating to bites and stings.

More worrying is the prospect of the arrival of the Asian tiger mosquito in Britain. Found in France, Germany and the Netherlands, where it thrives in warm, damp summers, it has also become established in northern Italy, where it transmits chikungunya fever, a disease that causes fever, intense headaches, joint pains and insomnia.

Wasps have also revelled in the humidity, with pest controllers reporting sightings of far larger nests. “These used to be the size of a basketball two to three years ago, but now nests can reach from the floor to the ceiling in people’s attics,” Savvas Othon, technical director of Rentokil, said. “Before, we saw around several thousand workers in a nest, now there are more like 18,000.” Even worse is the arrival of hornets, a cousin of the wasp, yet three times larger and far more aggressive.

A more benign nuisance are the swarms of fungus gnats, tiny black flies that are difficult to swat. These are attracted to breath and are enjoying the humid air.

So far, the wet weather has helped to keep down the flea population, but cats and dogs could be about to experience a lot more scratching if the temperature rises, as is forecast. “Humid conditions are definitely good for fleas, and if it becomes warm outside and people turn on their central heating indoors at night, then the flea population could suddenly accelerate,” Maggie Fisher, a veterinary parasitologist, said.

The legacy of last summer’s rains also lingers on. A big upsurge in rat numbers has been reported in Hull. They were flushed out of their holes by the rising waters during last summer’s floods. Since then they have had a perfect breeding season and are spreading to areas that were unaffected by the floods.

Gardeners are experiencing an onslaught of monstrous slugs. These belong to the black Arion ater group of slugs that ranges in colour from orange to black, reaching up to 10cm long. Although the numbers of slugs are not quite as alarming as last year, the problem is that the heaviest rains have come in August, which will hit the planting of new crops. However, it is actually the smaller, less visible slugs that are far more numerous and do most damage.

There is some good news. Oak trees in West London have been under attack from the oak processionary moth, but the Forestry Commission has started a vigorous spraying campaign to wipe out the moths’ nests and the signs are that they have contained the infestation, at least for now.