|8 May 2012 |
Wild spring weather baffles bugs
By Victoria Gill
Science reporter, BBC Nature
The wettest April in more than a century has caused problems for UK butterflies, bees and other bugs.
Conservation charities, Butterfly Conservation and Buglife, said the weather was likely to limit some species' opportunities to forage.
If the unfavourable conditions continue, they could lead to population crashes.
Experts are particularly concerned about honeybees, which will not forage in the cold and could run out of food.
But some of the country's invertebrate population, such as snails and slugs, are likely to benefit from the deluge.
According to the Met Office, April 2012 was the wettest on record since 1910; the UK received an average 126.5mm of rain.
Butterfly Conservation's Richard Fox said that this was "flying season" for some of our rarest butterflies and that it had been "clobbered by awful weather".
"Spring specialists", normally seen flying in April, such as the common blue and brown argus, only emerged in early May.
More worryingly, some of our rarer species were "confused" into emerging early by unseasonably warm temperatures in March.
"The worry about this April is that the butterflies that did emerge will have poor breeding success due to the bad weather," explained Mr Fox.
For example, he said, "the Duke of Burgundy and the pearl-bordered fritillary (both endangered in the UK) produce just one generation a year, and they're flying now".
"They can't change when they emerge. [So] unless conditions improve in the next few weeks their opportunities to breed will be very limited and, we may see population crashes later in the year or next spring."
'Winners and losers'While the recent weather extremes will be bad news for some invertebrates, Buglife pointed out that some would benefit. Some freshwater-dwelling species, such as mayflies, caddisflies and stoneflies, which struggled in the recent drought, could bounce back as their waterways and pond habitats fill up.
And slugs and snails, which have very leaky, permeable skins and need moisture to survive, are likely to feed and breed more in damp conditions.
For bees, it is a more mixed picture.
Dale Harrison from Buglife said that native bumblebees were likely to fare well, as they are "robust and well adapted to our environment and unpredictable weather".
"Whereas, the honeybee is non native, and just is not designed to live with such weather extremes."
The British Beekeepers Association (BBKA) agreed that they were concerned about honeybees' ability to withstand the cold, especially in the spring when they have had so little time to build up food stores.
Gill Maclean, a BBKA spokesperson, said: "If they can't get out, they have to rely on the stores they have in their hive.
"They've been cooped up in the hive all winter living on those stores, so that could be a problem.
"We would advise beekeepers to check their bees have sufficient food."
There is evidence that beetle populations suffer during years when spring and summer are relatively cold and rainy, so conservationists are also concerned to see how threatened species such as the oil beetle will fare.
Mr Fox said that he would be watching the forecast closely. He added: "Time will tell."