Nocturnal pollinatIon by Fungus gnats of the colombian endemic species, Pleurothallis marthae (orchidaceae: pleurothallidinae)

Abstract

Contemporary patterns of plant biodiversity result from the ecological and evolutionary processes generated by species interactions. Understanding these interactions is key for effective biodiversity conservation at the species and the ecosystem level. Orchid species often have highly specialised pollinator interactions, and the preservation of these is critical for in situ orchid conservation. The majority of orchid species occur in tropical regions, and information regarding their interactions is limited. We present data on pollinator identities, pollination mechanisms and flowering phenology of the Colombian endemic orchid, Pleurothallis marthae. We evaluated the mechanisms of attraction, the presence of osmophores, and the reproductive system of the species. Pleurothallis marthae is self-compatible with nocturnal anthesis pollinated by Mycetophila sp. (Mycetophilidae), probably attracted by a string fungus like smell liberated by the flower and Bradysia sp. (Sciaridae) that feed on nectar in the labellum. Osmophores and nectaries were detected in the epidermis of the sepals and petals. We present new evidence that the genus Pleurothallis is adapted to Diptera pollination. Our study indicates that the pollination mechanism of P. marthae is based on the nocturnal attraction of two species of fungus gnats, probably combining food attraction and brood place deception

A clarification of the distinctions between Pleurothallis talpinaria and Pleurothallis trimeroglossa (Orchidaceae: Pleurothallidinae) and an allied new species from Ecuador

“…data). These observations confirm the "uneasy alliance" comment by Luer (1998) Relatively little is known about pollination in Pleurothallis sensu Pridgeon et al (2005), but the few studies available suggest that Pleurothallis species are pollinated predominantly by Diptera and occasionally by Hymenoptera and Coleoptera (Archila & Chiron 2015, Calderón-Sáenz 2011, Duque 1993, Duque-Buitrago et al 2014. These scant field observations are being supplemented by micro-morphological studies of the labellum using scanning electron microscopy (SEM), which can be used to hypothesize putative pollination mechanisms for future field testing.…”

A new species of Pleurothallis (Orchidaceae: Pleurothallidinae) from Valle del Cauca, Colombia and a note on the relationship between subsections Macrophyllae-Racemosae and Antenniferae

“…Relatively little is known about the pollination of species of Pleurothallis sensu Pridgeon et al (2005), though most species are believed to be pollinated by Diptera and a few by Coleoptera and Hymenoptera (Duque 1993, Calderón-Sáenz 2011, Duque-Buitrago et al 2014. With regard to the role of labellar morphology in pollination in Pleurothallis sensu Pridgeon et al (2005) even less is known .…”

Two new species of Pleurothallis (Orchidaceae: Pleurothallidinae) allied to P. cardiothallis, with a note on flower activity

“…The information on the anatomy, palynology, and cytogenetics of the Pleurothallidinae is scarce relatively to the size of the subtribe (summarized in Pridgeon 2005), and even scantier are the studies on its reproductive biology (Chase 1985, Christensen 1992, 1994, Singer & Cocucci 1999 de Melo et al 2010, Endara et al 2010, Borba et al 2011, Pupulin et al 2012, Duque Buitrago et al 2013, Karremans et al 2016, Pansarín et al 2016, which somehow associate the mutual behavior of flowers and their pollinators. In Costa Rica, we documented some 30 specimens we interpret as P. cardiothallis from different localities on both watersheds of the Talamanca, Central Volcanic, and Tilarán mountain ranges (Fig.…”