Headspace volatiles from both nasonov and tarsal glands from ten foraging bees were routinely extracted using the protocol described by Jarau et al., (2006) . Glands were dissected by excising the 6 th and 7 th abdominal tergite region (nasonov gland) between the tarsus and metatarsus region (tarsal gland) in sterile saline solution and soaking in lml of pentane for 24 hours at room temperature (24°C), thereafter evaporating the solvent under a gentle stream of nitrogen gas to adjust 100µl per pair of glands (e.g., 10 nasonov glands in 500 µL pentane /10 tarsal glands in 500 µL pentane), thus 100µl of the pooled extracts corresponded to the gland content of one individual bee (one bee equivalent).
Extracts were stored in -20 o C until ready to use for chemical analyses. A pure pentane control was subjected to similar evaporation process.
Extracts were stored in -20 o C until ready to use for chemical analyses. A pure pentane control was subjected to similar evaporation process.
