• Acoustics;
  • insect traps;
  • longifolene;
  • sound production;
  • transects;
  • volatiles

Abstract.  1. The stag beetle, Lucanus cervus is Nationally Scarce in the UK, yet no methods exist for monitoring the abundance of adults or presence of the subterranean larvae.

2. Here, we describe the design of an aerial flight interception trap that can be used to catch adults. Various lures were tested and ginger root was found to attract both sexes in equal numbers.

3. Road transect surveys of adults killed by vehicles were found to produce reliable estimates of the total abundance of both sexes in areas up to about 12 km from the survey.

4. A novel use of radial diffusive samplers is described to infer the presence of larvae. Both larvae and adult females produce longifolene, which is highly attractive to males.

5. Larvae produce a characteristic stridulation pattern, which can be recorded and distinguished from sounds produced by other saproxylic beetles that may co-occur with L. cervus.

6. We conclude that aerial traps baited with ginger, combined with road transect surveys can be used to monitor population abundance of adults, while detection of longifolene and the characteristic stridulation pattern can be used to reveal larval presence, without destroying their fragile habitat.