The male sex pheromone of the butterfly Bicyclus anynana: towards an evolutionary analysis.
BACKGROUND
Female sex pheromones attracting mating partners over long distances are a major determinant of reproductive isolation and speciation in Lepidoptera. Males can also produce sex pheromones but their study, particularly in butterflies, has received little attention. A detailed comparison of sex pheromones in male butterflies with those of female moths would reveal patterns of conservation versus novelty in the associated behaviours, biosynthetic pathways, compounds, scent-releasing structures and receiving systems. Here we assess whether the African butterfly Bicyclus anynana, for which genetic, genomic, phylogenetic, ecological and ethological tools are available, represents a relevant model to contribute to such comparative studies.


RESULTS
Using a multidisciplinary approach, we determined the chemical composition of the male sex pheromone (MSP) in the African butterfly B. anynana, and demonstrated its behavioural activity. First, we identified three compounds forming the presumptive MSP, namely (Z)-9-tetradecenol (Z9-14:OH), hexadecanal (16:Ald ) and 6,10,14-trimethylpentadecan-2-ol (6,10,14-trime-15-2-ol), and produced by the male secondary sexual structures, the androconia. Second, we described the male courtship sequence and found that males with artificially reduced amounts of MSP have a reduced mating success in semi-field conditions. Finally, we could restore the mating success of these males by perfuming them with the synthetic MSP.


CONCLUSIONS
This study provides one of the first integrative analyses of a MSP in butterflies. The toolkit it has developed will enable the investigation of the type of information about male quality that is conveyed by the MSP in intraspecific communication. Interestingly, the chemical structure of B. anynana MSP is similar to some sex pheromones of female moths making a direct comparison of pheromone biosynthesis between male butterflies and female moths relevant to future research. Such a comparison will in turn contribute to understanding the evolution of sex pheromone production and reception in butterflies.
Nieberding
Caroline M
CM
Evolutionary Biology Group, Institute of Biology, Leiden University, Leiden, The Netherlands. c.m.nieberding@biology.leidenuniv.nl
de Vos
Helene
H
Schneider
Maria V
MV
Lassance
Jean-Marc
JM
Estramil
Natalia
N
Andersson
Jimmy
J
Bång
Joakim
J
Hedenström
Erik
E
Löfstedt
Christer
C
Brakefield
Paul M
PM
D000819:Animal Communication; D000818:Animals; D002080:Butterflies; D004463:Ecology; D019143:Evolution, Molecular; D005260:Female; D005786:Gene Expression Regulation; D007700:Kinetics; D008297:Male; D052586:Mating Preference, Animal; D008954:Models, Biological; D012724:Sex Attractants / Q000378:metabolism*; D012726:Sexual Behavior, Animal; D012903:Smell; D014921:Wings, Animal / Q000502:physiology
D012724:Sex Attractants