[en] Since its description by Krüger, there is so much confusion in the taxonomy of the Bombus laesus-group and this one has always raised discussion within the scientific community. Previously considered as a separate subgenus (Laesobombus Skorikov), now included into the Thoracobombus Dalla Torre, Bombus mocsaryi and Bombus laesus were merged into a single taxon called Bombus laesus. In this paper we attempt to shed some light in this confusion by studying the male cephalic labial secretion. This chemical composition is reported for the first time. The bumblebee male cephalic labial secretions act as sexual attracting pheromones and they are known as generally very species-specific. Therefore, the strong differences between the secretion on B. mocsaryi and B. laesus lead to take these taxa as good separated species.
