The humble ginger root could be the key to conserving the UK's largest and most spectacular terrestrial beetle the stag beetle. Ecologists from Royal Holloway, University of London and the University of York have developed a series of new methods to monitor stag beetle numbers including ginger lures to trap adult beetles and tiny microphones to detect sounds made by the larvae in their underground nests. Conservation efforts have been hampered until now because ecologists lacked a reliable way of monitoring stag beetle numbers.
The new research, published in the Royal Entomological Society's journal Insect Conservation and Diversity, found that a combination of ginger-baited aerial traps to catch adult stag beetles, plus tiny microphones to record the underground larvae's sounds and samplers to detect the chemicals they emit, give an accurate picture of the species' abundance.
According to Dr Deborah Harvey, one of the study's authors: "Our new methods offer genuine promise for monitoring the population of this elusive and rare insect, one that we think is declining across much of its European range. We need to know where the stag beetle lives and in what numbers to be able to conserve it effectively."
Harvey and her colleagues discovered ginger was irresistible to adult stag beetles only after testing the attractiveness of many other fruit and vegetables including banana, strawberry, tomato and cherry as well as wine and beer. Ginger works because it contains large amounts of alpha copaene, a chemical known to attract other insects that live in dead and decaying wood.
By using ginger, and designing the trap using heavy duty plastic, Harvey was able to produce a very cost-effective trap, which is vital because most insect monitoring in the UK is done by a small army of dedicated but unfunded amateur recorders.
Using other methods of trapping insects, such as light traps or traps baited with food, do not
|Contact: Dr. Deborah Harvey|