Notes on pollination ecology and floral scent chemistry of the rare neotropical orchid Catasetum galeritumRchb.f.

Abstract

The neotropical orchid genus Catasetum embraces about 180 species that produce perfume as reward for pollinators (i.e. male euglossine bees). Among the ca. 1000 perfume‐rewarding plants, Catasetum species are the best studied with respect to their natural history. Nevertheless, the pollination ecology of most species (> 80%) remains unknown. Here, we investigated the pollination ecology and floral scent chemistry of C. galeritum, a rare species endemic to the poorly investigated Brazilian Amazon. Flowers of C. galeritum were visited only by male bees of Eufriesea superba. Its perfume bouquet was composed of six volatiles, with 1,4‐dimethoxybenzene accounting for about 85% of the total scent discharge. Curiously, this compound is a potent attractant of more than 40 euglossine species. The absence of euglossine species other than Ef. superba on flowers of C. galeritum might be, therefore, be mediated by a modifier effect of another compound(s) in its floral scent bouquet.

Pollination of the strongly scented Sarcoglottis acaulis (Orchidaceae) by male orchid bees: nectar as resource instead of perfume

“…In orchids, to determine if a floral visitor act as pollinator, it is essential that both removal and deposition of pollinia occur, since the pollen located within these structures may not be easily dispersed from some species, such as Epidendrum paniculatum (Pansarin 2003), Rodriguezia bahiensis (Carvalho & Machado 2006) and Catasetum (Carvalho & Machado 2002; Milet‐Pinheiro et al . 2015, 2018; Brandt et al . 2020), among others.…”

The role of volatiles in plant communication

“…The chemical complexity in floral scent entails interactions between neurons detecting individual chemical components, together producing the sensation of a bouquet, which is different from the sum of the individual components (Strutz et al ., ; Schiestl, ). An example for this is scent compounds that modify the attractive function of other molecules, as was shown, for example, in scent bouquets of orchids attracting fragrance‐gathering male euglossine bees (Milet‐Pinheiro et al ., ). Floral scent is mostly detected by insects with neurons located on the antennae, but recently olfactory neurons on the tip of the proboscis have also been characterized (Haverkamp et al ., ).…”

Flora of Ferruginous Outcrops Under Climate Change: A Study in the Cangas of Carajás (Eastern Amazon)

“…Some studies analyzed plant species of economic interest pollinated by bees ( Cavalcante et al, 2018 ; Krug et al, 2018 ; Beyerlein et al, 2019 ) or by complex systems involving multiple insects ( Dattilo et al, 2012 ; Campbell et al, 2018 ). A small additional amount of data is available on interactions between plants and pollinators in the region, including bees ( Moura et al, 2011 ; Novais and Absy, 2013 ; Ferreira and Absy, 2017 ; Oliveira et al, 2017 ; Milet-Pinheiro et al, 2018 ), beetles ( Seymour and Matthews, 2006 ; Gottsberger and Webber, 2018 ), moths ( Cruz-Neto et al, 2011 ), wasps ( Nazareno et al, 2007 ), birds ( Vicentini and Fischer, 1999 ), and bats ( Gribel et al, 1999 ). None of the quoted studies analyzed the potential impact of climate change on those interactions.…”