Contact Sex Pheromones Identified for Two Species of Longhorned Beetles (Coleoptera: Cerambycidae)Tetropium fuscumandT. cinnamopterumin the Subfamily Spondylidinae (original) (raw)

2011, Environmental Entomology

Male Tetropium fuscum (F.) and T. cinnamopterum Kirby mated with live and dead (freeze-killed) conspeciÞc females upon antennal contact, but did not respond to dead females after cuticular waxes were removed by hexane rinsing. SigniÞcantly fewer males of each species attempted to copulate with live or dead heterospeciÞc females than with conspeciÞcs, indicating that mate recognition was mediated by species-speciÞc contact sex pheromones in the femaleÕs cuticular hydrocarbons. GC/MS analysis of T. fuscum elytra identiÞed n-alkanes and mono-methyl branched alkanes of which 11-methylheptacosane and 3-and 5-methyltricosanes were dominant in females. Full male responses, including copulatory behavior, were restored with application of enantiomerically pure synthetic (S)-11-methyl-heptacosane at 40 g /female (one female equivalent) but not with racemic or (R)-11-methyl-heptacosane. The cuticular hydrocarbons on T. cinnamopterum elytra included 11-methyl-heptacosane as well as n-alkanes, methyl-branched alkanes, mono-alkenes, and (Z, Z)-6, 9-alkadienes. (Z)-9-pentacosene, (Z)-9-heptacosene, and 11-methyl-heptacosane were female dominant, but only (Z)-9-pentacosene elicited precopulatory behaviors in conspeciÞc males at levels similar to those behaviors elicited by unrinsed females, but elicited copulation in fewer than half of males. At female equivalent dosages (10 g), neither (Z)-9-heptacosene nor (S)-11-methylheptacosane elicited responses in males that were signiÞcantly different from those responses to a rinsed female but when applied together, the proportion of males responding was signiÞcantly increased. 11-methyl-heptacosene is thus a contact pheromone component common to both species, which may explain the heterospeciÞc mating attempts by some males.