Making the invisible visible: determining an accurate national distribution of Elater ferrugineus in the United Kingdom using pheromones

To date, conservation-status saproxylic beetle species in the UK have been monitored by chance findings or by monitor-based observational studies. Here, using Elater ferrugineus as our target species, we present the first national distribution survey carried out in the UK or across mainland Europe on such a species using chemicals produced by the insect.

Over 3 years, mark-release-recapture studies were performed across the UK, using 416 lured (pheromone) traps monitored by volunteer recorders; the first survey in Europe to do so. Traps were baited with 7-methyloctyl- (Z)-4-decenoate, a compound previously identified as a female sex pheromone.

The results were used to plot a distribution map and investigate factors that may influence the distribution, including summer temperatures, possible habitat availability and larval food source.

The survey revealed a south-eastern distribution of E. ferrugineus in the UK, which was suggested by previous casual studies.

A correlative model was fitted to the data, indicating that 55% of the variation in the distribution of E. ferrugineus was explained by climatic variables (temperature and wind speed).