Individual worker bees of F. varia were collected in small glass vials and killed by freezing. The last pairs of legs were cut off before chemical extraction, since workers of F. varia usually carry a considerable amount of plant resins in the corbiculae of their last pair of legs (Nogueira-Neto 1997). The cuticle lipids were extracted by immersion of the whole body in hexane (0.5 ml) for 1 min. Extracts (1 ml) were analysed in a gas chromatograph directly coupled to a mass spectrometer (SHIMADZU, model GCMS-QP2010), equipped with a DB-5MS chromatography column, using helium as the carrier gas. The column was initially set at 150 C for 3 min, then programmed at a rate of 3 C/min to
280 C, and then held at 280 C for 15 min. The carrier gas was helium at a flow rate of 1 ml/min. The injection mode was splitless and the injection temperature was 250 C. eparated compounds were identified from their mass spectra, using the software programme GCMS solutions for Windows