Notes on the pollination of the perfume flowers of Gloxinia perennis (Gesneriaceae) by euglossine bees / Notas sobre la polinización de las flores perfumadas de Gloxinia perennis (Gesneriaceae) por abejas euglossine

During a field course held at the ¿Tropenstation La Gamba¿ 2005, the pollination of cultivated Gloxinia perennis (Gesneriaceae) was studied. The flowers provide fragrance as a floral reward for male euglossine bees. Three species of euglossine bees (Eulaema meriana, two Euglossa species of different size) were observed to visit the flowers, all collecting the fragrance in the usual way. However, only Eulaema meriana was large enough to touch the anthers and stigma and proved an effective pollinator. Flower visitation by Eulaema meriana was in the early morning, starting with dawn and lasting for approximately one hour. No overlap with visitation of other bees was observed. The bees seem to follow a ¿first come, first served¿ strategy. The Euglossa species visited the flowers in a staggered way in the subsequent morning hours, with some overlap. The time of visitation and back-loading of the collected fragrance was closely linked with the species and size of the bees. From earlier and the present observations, it may be concluded that the flowers of Gloxinia perennis are specifically adapted to the pollination by Eulaema bees, even though the fragrance is not specifically addressed to them.