Chemical Communication in the Honey Bee Scarab Pest Oplostomus haroldi : Role of ( Z )-9-Pentacosene
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Date
2012Author
Fombong, Ayuka T
Teal, Peter E A
Arbogast, Richard T
Ndegwa, Paul N
Irungu, Lucy W
Torto, Baldwyn
Language
enMetadata
Show full item recordAbstract
Oplostomus haroldi Witte belongs to a unique
genus of afro-tropical scarabs that have associations with
honey bee colonies, from which they derive vital nutrients.
Although the attributes of the honey bee nest impose barriers to communication among nest invaders, this beetle still
is able to detect conspecific mates for reproduction. Here,
we show, through behavioral studies, that cuticular lipids
serve as mate discrimination cues in this beetle. We observed five steps during mating: arrestment, alignment,
mounting, and copulation, and a post-copulatory stage, lasting ~40–70 % of the total mating duration, that suggested
mate guarding. Chemical analysis identified the same nine
straight-chain alkanes (C23–C31), six methyl-branched alkanes (6), and five mono-unsaturated alkenes in the cuticular lipids of both sexes. Methyl alkanes constituted the
major component (46 %) of male cuticular lipids, while
mono-unsaturated alkenes were most abundant (53 %) in
females. (Z)-9-Pentacosene was twice as abundant in
females than in males, and ~20 fold more concentrated in
beetles than in worker bees. In mating assays, (Z)-9-pentacosene elicited arrestment, alignment, and mounting, but not
copulation, by male beetles. These results represent the first
evidence of a contact sex pheromone in a scarab beetle.
Such contact pheromones may be an essential, cryptic
mechanism for arthropods associated with eusocial insects.
Publisher
University of Nairobi