Floral visitors of Kluai Bua Si Som (Musa rubra - Musaceae): an ornamental plant in Thailand

Musa rubra, a native wild banana in Thailand, has aesthetic value as an ornamental plant given its showy inflorescence with colorful orange bracts. It flowers year-round, attracts birds and other animal visitors, and offers popular photo spots in gardens. The aim of this study was to examine the flowering time, flower visitors, and mating system of M. rubra in Mae Yom National Park, Phrae, Thailand. We recorded flowering time and both diurnal and nocturnal flower visitors. Diurnal visitors were recorded using direct observation and a camera trap between 6.00 and 18.00 h. Nocturnal visitors were recorded by an infrared camera trap between 18.00 and 6.00 h. In order to assess the mating system, we conducted a pollination experiment with three treatments: open (inflorescences exposed to all flower visitors), closed (inflorescences enclosed in mesh bags) and hand-pollinated (pollen transferred by hand from a male inflorescence to a female inflorescence). We collected all fruits 40 days later to determine seed set. It was found that bracts of female and male inflorescences open at 10.30±0.08 h and 10.27±1.11 h, respectively. Birds (Arachnothera spp.), hoverflies (Graptomyza longirostris), stingless bees (Apidea), and several butterflies (Nymphalidae, Papilionidae) visited M. rubra. Surprisingly, none of the pollination treatments resulted in seed set. It is suspected that M. rubra is self-incompatible, and that our population study may be the result of vegetative propagation (i.e., all individuals are genetic clones), thus explaining the lack of seed set in spite of certain pollen transfer. This study may provide important information about M. rubra cultivation and breeding for commercial purposes.