This is a pioneer study on the chemical communication of butterflies, particularly for the very diverse family Hesperiidae (4,000 species worldwide). The genus studied is formed by very similar species that cannot be easily differentiated by taxonomists. How can these butterflies recognize mates precisely and avoid hybridization? By using GC-MS analyses, a total of 125 different compounds exclusively present in the male scent-organs were documented. Great interspecific differences and much narrower intraspecific variability in the chemical profiles were observed. As a result most species can be identified based on their chemical profiles, except for a closely related species pair for which hybridisation is common in nature. The dynamics of chemical versus genetic distances indicate two different phases: a faster, but more variable, initial chemical divergence at lower genetic divergences (probably related to speciation) and a slower and constant differentiation (drift). This is the first time that a comparative chemical analysis is performed in Hesperiidae and the results suggest that this is a group with a great potential for the study of chemical communication that deserves further attention. The study has been led by researchers at R. Vila's lab and has been recently published in Organisms Diversity and Evolution magazine. Ref article: Morphological and chemical analysis of male scent organs in the butterfly genus Pyrgus (Lepidoptera: Hesperiidae). 2014. Hernández-Roldan et al. Org Divers Evol; DOI 10.1007/s13127-014-0170-x