Figure 3: Experiments to identify the female sex pheromone.

Frequency of decision for sample or control of naïve L. heterotoma males in a y-tube experiment when choosing between the control and (a) the odour of virgin L. heterotoma females, (b) an extract of L. heterotoma females, (c) the CHCs or (d) the iridoid compounds from the female extract. (e–h) Total ion current chromatograms illustrating the manipulation of the iridoid fraction of the female extract and the frequency of decision in the corresponding y-tube experiment when testing the manipulated iridoid fraction against the control. Compounds p1 and p2 were tentatively identified as iridodials; p3 was behaviourally inactive and thus not identified; p6 is (+)-isoiridomyrmecin; p7 was tentatively identified as a third iridomyrmecin; x denotes contaminations. P-values (rounded to the third decimal) are given for the two-sided binomial test (a–h). Bar colours indicate sample (blue) and control (brown). For each experiment n=30.