Functional morphology in male euglossine bees and their ability to spray fragrances (Hymenoptera, Apidae, Euglossini)

Abstract - Male orchid bees (Euglossini) collect fragrant substances from exogenous sources and accumulate them in modified hind tibiae. The subsequent fate of these fragrances is unknown. Here, a new hypothesis is presented that orchid bee males are capable of actively spraying off the stored fragrant substances. The fragrances are hypothesized to be transferred to the mid tibial tufts, which are then held such that when the hind wings are vibrated the jugal combs hit the tibial tufts and spray off the fragrances. To test this hypothesis, the morphology of mid tibial tufts and hind wing jugal combs was examined on male Euglossini from all known genera. The functional link between the two morphological structures could be established, including the generation of aerosol clouds. It is postulated that during the so-called "ventilating" behavior at their courtship sites the animals spray fragrances and this hypothesis is discussed with respect to previously published observations and assumptions.