The reserve is noted for its large and varied butterfly population.

Others try to help the butterfly population by planting native plants which rare or threatened butterflies feed on.

Existing up-to-date records on butterfly populations made it unnecessary to visit about 20 percent of the sites.

The trust wants to gain an insight into the county's butterfly population.

"Spraying for mosquitoes can have a dramatic effect on butterfly populations," he said.

But actually it spreads disease among butterflies, mixes butterfly populations and puts them where they're not supposed to be.

The practice greatly reduces the butterfly population and shows an astounding ignorance of how the environment works.

He did an exhaustive study into the effects of pollution on the local butterfly population.

But when average temperatures warmed slightly above a critical threshold, the entire butterfly population would suddenly crash.

The site has been subject to illegal raves in the past, which have significantly harmed the butterfly population.