Lewis Smith, The Times 15 Sep 08;
The rasping summer sound of grasshoppers chirping in fields and meadows is to be used to help to track climate changes.
Grasshoppers, along with bush crickets, have been identified as the ideal insects for a public monitoring system. There is a now a scheme to record sightings of all 27 native species of grasshoppers and crickets in Britain based on the system that enabled scientists to follow the spread of harlequin ladybirds.
The harlequin, an invasive species that competes with and often eats native ladybirds, arrived from the Continent in 2004 and has spread rapidly.
The public reporting system that was introduced to monitor the ladybird is regarded by researchers as an outstanding success and they now intend to use it to find out how climate change is affecting other insects.
Climate change is driving insects and other creatures to find new places to live as temperatures rise too high for their comfort or make it possible for them to move into a previously unfavoured area. Grasshoppers and crickets are regarded as ideal for the project because they are easily picked out by the public from the huge array of other insects and are among the “most charismatic” of the nation’s creepy-crawlies.
Researchers are convinced that once members of the public “get their eye in” they will be able to spot all 27 species, along with a handful of foreign visitors.
Even if telling the difference between a wart-biter bush cricket and the large marsh grasshopper proves too much to manage on a stroll in the countryside, enthusiasts taking part can send photographs for experts to identify.
Butterflies have until now been used as the primary insect indicators of climate change in Britain because they are among the most visible and well-known.
Grasshoppers and crickets are regarded as valuable indicators of climate change because in many ways they are more sensitive to it than other insects. Researchers hope to harness public enthusiasm for them to provide a new source of data.
More than 60,000 records of ladybirds were generated by the Harlequin Ladybird Survey, 20,000 of the invasive species and a further 40,000 of native ladybirds.
Helen Roy, of the Centre for Ecology and Hydrology, said of the harlequin reporting scheme: “It’s been such a great way to get people involved and we got high-quality data.
“We now want to expand the system and we’ve chosen grasshoppers and crickets because they are charismatic and they are showing range expansion already. We want to use them in the same way the butterflies have been used to show expansion.”
Long-winged coneheads, a type of cricket species, have been expanding into new territories as temperatures have risen under climate change. Until the 1980s they were confined to the South Coast, but they can now be found north of Leicester.
Similarly Roesel’s bush cricket was largely restricted to the Thames and Solent Estuaries in the mid-20th century, but is now seen across Britain.
Other species may be declining and the project should also help to identify where a species is in trouble. The common grasshopper is among those giving concern and it is thought that higher temperatures are a factor.
Peter Sutton, a science teacher and an authority on grasshoppers and crickets, has been closely involved in the scheme, which is expected to begin in November.
“These insects are the foremost indicators of climate change and are responding dramatically to global warming,” he said.
“Temperature increases have allowed them to expand their habitat.”
