Characteristic odor of Osmoderma eremita identified as a male-released pheromone.
Osmoderma eremita (Scopoli) is an endangered scarab beetle living in hollow trees. It has mainly been known for its characteristic odor, typically described as a fruity, peachlike or plumlike aroma. The odor emanating from a single beetle can sometimes be perceived from a distance of several meters. In this paper, we show that the characteristic odor from O. eremita is caused by the compound (R)-(+)-gamma-decalactone, released in large quantities mainly or exclusively by male beetles. Antennae from male and female beetles responded in a similar way to (R)-(+)-gamma-decalactone in electroantennographic recordings. Field trapping experiments showed that (R)-(+)-gamma-decalactone is a pheromone attracting female beetles. Lactones similar to (R)-(+)-gamma-decalactone are frequently used as female-released sex pheromones by phytophagous scarabs. This is, however, the first evidence of a lactone used as a male-produced pheromone in scarab beetles. We propose that the strong signal from males is a sexually selected trait used to compete for females and matings. The signal could work within trees but also act as a guide to tree hollows, which are an essential resource for O. eremita. Males may, thus, attract females dispersing from their natal tree by advertising a suitable habitat. This signal could also be exploited by other males searching for tree hollows or for females, which would explain the catch of several males in our traps.
Larsson
Mattias C
MC
Department of Ecology, Lund University, SE-223 62 Lund, Sweden. mattias.larsson@vv.slu.se
Hedin
Jonas
J
Svensson
Glenn P
GP
Tolasch
Till
T
Francke
Wittko
W
D000818:Animals; D002628:Chemoreceptor Cells / Q000187:drug effects; D001517:Coleoptera / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D007783:Lactones / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D008297:Male; D009812:Odorants; D012724:Sex Attractants / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000502:physiology*
D007783:Lactones; D012724:Sex Attractants; C109757:decan-4-olide