Mandibular gland component analysis in the head extracts of Apis cerana and Apis nigrocincta

Head extracts of workers and mated queens of the closely related species of Apis cerana and A. nigrocincta from Sulawesi, Indonesia were quantitativel y analyzed by gas chromatography-mass spectrometry for several mandibular g land components. The amounts of many compounds were significantly different between species for both queens and workers. Quantities of 10 of the 16 co mpounds quantified in queen bees differed significantly between the two spe cies. Of the three known mandibular gland retinue pheromone components in A . cerana queens [(E)-9-oxodec-2-enoic acid (9-ODA), (E)-9-hydroxydec-2-enoi c acid (9-HDA), and methyl p-hydroxybenzoate (HOB)], the amounts of 9-HDA a nd HOB were significantly different between species. Quantities of 6 of the 11 compounds quantified in worker bees differed significantly between the two species. This quantitative analysis supports the hypothesis that A. cer ana and A. nigrocincta are indeed separate species.