02430nas a2200217   4500008004100000020001400041245014900055210006900204260000800273300001200281490000700293520161600300100002101916700002501937700002001962700002501982700002602007700002202033700002202055856013502077       2010                        eng d  a0937-740900aPheromone of the elm bark beetle Scolytus laevis (Coleoptera: Scolytidae): stereoisomers of 4-methyl-3-heptanol reduce interspecific competition0 aPheromone of the elm bark beetle Scolytus laevis Coleoptera Scol  cSep  a179-1870 v203 aStereoisomers of 4-methyl-3-heptanol (MH) are pheromone components of several Scolytus bark beetles. The elm bark beetle Scolytus laevis (Coleoptera: Scolytidae) has in previous studies been caught in traps baited with commercial MH containing all four stereoisomers, but the lure has been considered a weak attractant. In this study, we addressed the question whether stereospecific responses by S. laevis to stereoisomers of MH might contribute to its niche separation from other sympatric Scolytus species. Using GC-MS, we analyzed extracts of hindguts and abdomens from male and female S. laevis and the sympatric S. triarmatus. We also tested all four MH-stereoisomers individually and in combinations in the field to determine their role for S. laevis. All four stereoisomers were synthesized via a boronic ester method with 1,2-dicyclohexylethanediol as chiral director. In addition, the (3S,4R)-stereoisomer of MH was prepared through enantioselective, lipase-mediated transesterification of a mixture of the four stereoisomers of MH. Females of both species contained small amounts of syn-MH, and males contained trace amounts of anti-MH. The anti stereoisomer (3R,4S)-MH was attractive to male and female S. laevis, whereas the syn stereoisomer (3S,4S)-MH acted as an inhibitor or deterrent and reduced the catch when added to the attractive isomer. The syn isomer is the main aggregation pheromone component of the larger and sympatric S. scolytus and possibly also of S. triarmatus. The avoidance response of S. laevis to the (3S,4S)-stereoisomer may reduce interspecific competition for host trees.1 aAnderbrant, Olle1 aMatteson, Donald, S.1 aUnelius, Rikard1 aPharazyn, Philip, S.1 aSantangelo, Ellen, M.1 aSchlyter, Fredrik1 aBirgersson, Goran  uhttps://weevil.myspecies.info/pheromone-elm-bark-beetle-scolytus-laevis-coleoptera-scolytidae-stereoisomers-4-methyl-3-heptanol-re