Nectar sugar concentration in W. pillansii varied widely,
ranging between 8.5 and 25%, with a mean (±SE; this notation
will be used hereafter) of 16.6 (±1.1; N=21 flowers). Sugar
content ranged between 0.093 and 0.273 mg/µL (0.179±0.058).
When among-flower differences in nectar features were
correlated with variations in yeast density, both nectar
concentration and sugar content showed a significant declining
trend with increasing yeast density (Fig. 4). There was a
significant negative correlation between yeast density and sugar
content (Rs =−0.463, P=0.039), and between yeast density and
nectar concentration (Rs =−0.470, P=0.037).