Skin-deep discrimination

Chemical communication plays a crucial role in the complex societies of social insects such as ants, bees, and wasps. Several ant species recognize nestmates on the basis of a cocktail of dozens of hydrocarbons in their cuticle. However, cuticular hydrocarbons (CHCs) are known to vary with reproductive status in some species, suggesting they also play a role in the recognition of castes within colonies. In the 11 August PNAS, Vincent Dietemann and colleagues at the University of Würzburg provide evidence that this is indeed the case (PNAS, DOI:10.1073/pnas.1834281100, August 11, 2003).

Dietemann et al. used solid-phase microextraction to extract CHCs from individuals of Myrmecia gulosa, an ant native to Australia. Analysis of the extract confirmed that the cocktail of CHCs differs between reproductive queens and infertile workers from the same colony, with two compounds, both containing 25 carbon atoms, being characteristic of queens. Purified CHC extracts from...