[HELICONIUS] Antiaphrodisiac proved in melpomene

[James Mallet]

I thought you all ought to see this:

Schulz, S., C. Estrada and S. Yildizhan. 2008. An antiaphrodisiac in 
Heliconius melpomene butterflies. J. Chem. Ecol., 34: 1-12.
Abstract: Gilbert (1976) suggested that male-contributed odors of 
mated females of Heliconius erato could enforce monogamy. We 
investigated the pheromone system of a relative, Heliconius 
melpomene, using chemical analysis, behavioral experiments, and 
feeding experiments with labeled biosynthetic pheromone precursors. 
The abdominal scent glands of males contained a complex odor bouquet, 
consisting of the volatile compound (E)-beta-ocimene together with 
some trace components and a less volatile matrix made up 
predominately of esters of common C16- and C18-fatty acids with the 
alcohols ethanol, 2-propanol, 1-butanol, isobutanol, 1-hexanol, and 
(Z)-3-hexenol. This bouquet is formed during the first days after 
eclosion, and transferred during copulation to the females. Virgin 
female scent glands do not contain these compounds. The transfer of 
ocimene and the esters was shown by analysis of butterflies of both 
sexes before and after copulation. Additional proof was obtained by 
males fed with labeled D-13C6-glucose. They produced 13C-labeled 
ocimene and transferred it to females during copulation. Behavioral 
tests with ocimene applied to unmated females showed its repellency 
to males. The esters did not show such activity, but they moderated 
the evaporation rate of ocimene. Our investigation showed that 
beta-ocimene is an antiaphrodisiac pheromone of H. melpomene.

James Mallet
http://www.ucl.ac.uk/taxome/jim/