author(s)
Bridget O Bobadoye

abstract
The cognitive ability to identify and respond differently to the presence of either a nest mate or non-nest mate exists in many organisms and is vital for members of most social insect colonies. Bioassay experiments showed that all four bee species could successfully discriminate nest mates from non-nest mates, as they all exhibited more aggression when exposed to hetero-specific nest mate extracts than when exposed to con-specific nest mate extracts (within or between nest), although aggression between same species colonies was not significantly different, with the species Meliponula ferruginea (black) exhibiting the most aggression, followed by Hypotrigona ruspoli, and Plebeina hildebrandti, while the least aggressive was Hypotrigona gribodoi. A high number of guard bees opened their mandibles and even proceeded to attack at their nest entrances when presented with an extract from (between nest) con-specific non nest mates and (between species) hetero-specific non-nest mates compared to when presented with a solvent control. Gas chromatography revealed similar patterns of recognition cue compounds present in cuticular profiles and nest materials (nest entrance and involucrum sheaths) from the four African meliponine bee species. This comprised of alkanes, alkenes and methyl-branched alkanes ranging from C8-C35 with trace amounts of acids, esters, aldehydes and ketones. The electro-antennography response to 9-Hexadecenoic acid and β-Farnesene (E) is consistent with that in Apis mellifera which showed positive responses to tricosene and the 16-C and 18-C fatty acids in particular, which suggests a generality of signal function in nest mate recognition between these closely related bees of the same family.