Bugging the bugs to save threatened species

Published Date: 10 January 2011
By John von Radowitz

Scientists involved in a conservation project have been bugging the homes of stag beetle larvae.

Tiny microphones are being used to eavesdrop on the white grubs that live in buried rotting wood. The larvae make rasping sounds known as "stridulation", which experts believe are used as a form of communication.

Listening to the larvae is one new technique being tried out to get a better idea of stag beetle numbers.

The stag beetle, Lucanus cervus, can reach a length of several centimetres. Well known for the dramatic "antlers" sported by males, it was once common but is now classified as "nationally scarce" in the UK.

Attempts to conserve it have been hampered by the lack of reliable population monitoring.

Scientists are also experimenting with ginger to lure flying beetles into aerial traps to be counted. They discovered adult stag beetles find ginger irresistible. It contains large amounts of alpha copaene, a chemical known to attract insects that live in dead and decaying wood.

The mini-microphones provide a means of detecting and tracking larvae without damaging their underground habitats.

They are being used alongside sensors that detect chemicals emitted by the grubs.

The team found stag beetle larvae stridulation patterns are very different from those of other insect species.

"Stridulation is likely to be a form of communication between larvae," said study leader Dr Deborah Harvey, from Royal Holloway, University of London. "It increases if larvae are handled or placed in solitary confinement."

The new technique could help conserve other rare species, she said, adding: "Acoustic detection of insects as a sampling method is very underused, but we believe it could have great potential in detecting larvae in the field."

http://news.scotsman.com/news/Bugging-the-bugs-to-save.6684903.jp