Floral visitors of Mormodes maculata (Orchidaceae, Catasetinae) and pollinarium placement on a specialized orchid bee

Background and Aims: Mormodes is the only orchid genus exhibiting floral handedness (enantiostyly), a trait presumed to promote cross-pollination. Despite this unique floral morphology, little is known about its reproductive biology or pollinators. The aim of this study was to characterize the floral visitors of two varieties of Mormodes maculata and assess the subsequent positioning of their pollinarium. Methods: We conducted field observations on 12 flowering individuals of Mormodes maculata representing two floral varieties, M. maculata var. maculata and M. maculata var. unicolor. We observed, captured, and identified floral visitors and documented the specific body region of the bee where the pollinia were attached. Key results: We identified Euglossa obrima as the pollinator of Mormodes maculata after observing an individual carrying a laterally attached pollinarium, consistent with the flower’s handedness. We also recorded Eulaema polychroma as an occasional floral visitor, exclusively to M. maculata var. maculata, but without evidence of effective pollination. Conclusions: Our findings reveal a highly specialized pollination mechanism in Mormodes maculata, driven by the interaction between floral handedness and a specialized orchid bee. This high degree of specialization should be considered when developing conservation strategies for the species.