|
Pheromone Group
|
| Homepage |
| Agenda (What's up?) |
| Pheromones ? |
| Research |
| Publications |
| Courses |
| Popular science |
| Photos |
| Links |
| Site running since Sept 25, 1995. |
|
Section of Chemical Ecology/Ecotoxicology |
Dept. Ecology |
|
Lund University |
|
||||||
| ||||||||||
Chemical communication and dispersal ecology in Osmoderma eremita
The hermit beetle Osmoderma eremita lives exclusively inside hollow deciduous trees. It is dependent on large amounts of wood mould, i.e. rotten, loose wood mixed with insect fragments, fungi, and old bird nests. It is today threatened throughout its range in Europe because its habitat has become increasingly fragmented in the modern agricultural landscape. Due to its status as indicator species of the diverse insect fauna associated with hollow trees, it has high conservation priority according to the European Union's Habitat Directive.
 An old oak, the habitat for many threatened saproxylic beetles, with Lindgren funnel traps for non-destructive trapping.
The hermit beetle is known for its fruity plum-like scent, which can be perceived by the human nose at distances of tens of meters. We have identified this odour as (R)-(+)-γ-decalactone, and shown that it is released exclusively by males and functions as a sex pheromone for attraction of conspecific females. The odour is emitted in large amounts and can be detected inside hollow trees with traditional headspace sampling techniques.
We have shown that O. eremita beetles are equipped with olfactory receptor neurones (ORNs) that are specific to the (R)-enantiomer of γ-decalactone, and they lack ORNs for detection of the opposite enantiomer. As the racemic mixture of this compound is much cheaper to purchase compared to the pure (R)-enantiomer, the blend can be used for cost-effective monitoring of this species. We are also using radio telemetry to track movements of O. eremita females to study their dispersal capacity, and how vulnerable they are to habitat fragmentation. A miniature tag is attached to a beetle that has been captured in a pheromone trap, i.e., is dispersing, and its subsequent movements are recorded. Using mark-release-recapture data and radio telemetry, and pheromone-baited traps suspended from oak branches to capture beetles during their dispersal, we hope to get more robust estimates on dispersal distances and population sizes of this threatened species.
References:
Larsson, M.C., Hedin, J., Svensson, G.P., Tolasch, T. and Francke, W. (2003) Characteristic
odor of Osmoderma eremita identified as a male-produced pheromone. J. Chem. Ecol.
29:575-587. [download pdf]
Svensson, G.P., Larsson, M.C. and Hedin, J. (2004) Air sampling of its pheromone to monitor
the occurrence of Osmoderma eremita, a threatened beetle inhabiting hollow trees. J.
Insect Conserv. 7:189-198. [download pdf]
Svensson, G.P. and Larsson, M.C. (2008) Enantiomeric specificity in a pheromone-kairomone
system of two threatened saproxylic beetles, Osmoderma eremita and Elater
ferrugineus. Journal of Chemical Ecology, 34:189-197. [download pdf]
| ||||||||||
