Floral biology of Schismatoglottis baangongensis (Araceae) in West Sarawak, Borneo

Abstract

The flowering mechanism, visiting insect activities, reproductive system, and floral scent composition of Schismatoglottis baangongensis a Northwest Bornean locally endemic limestone-restricted protogynous mesophyte were investigated. Anthesis started at dawn and lasted ca 29 h. Fruit set for open pollination (93 %) and restricted access pollination (88 %) were high. Colocasiomyia (Diptera, Drosophilidae) and Cycreon (Coleoptera, Hydrophilidae) were the main pollinators. Colocasiomyia flies present in much higher numbers than Cycreon beetles individually carried significantly less pollen load. Chaloenus (Chrysomelidae, Galerucinae) was inadvertent pollinators, and Atheta (Coleoptera, Staphylinidae) passive visitors. Pollen transferal between dissimilar insect genera (Colocasiomyia and Chaloenus) is reported for the first time. Low pollen/ovule ratio of S. baangongensis indicated an efficient pollination mechanism. Ester compound class floral odours, especially the dominant compounds 3-butenoic acid, 3-methyl-, methyl ester, were decisive in attracting pollinators. The spadix appendix of S.baangongensis was the main olfactory body although the spathe was detected to release an additional N-containing compound, an indole.

Thermogenesis in four species of Schismatoglottis Calyptrata Clade (Schismatoglottideae: Araceae)

“…The diurnal pollination of Schismatoglottis species of the Calyptrata Clade is mainly achieved by Colocasiomyia drosophilid flies (Diptera, Drosophilidae) and secondarily by Cycreon hydrophilid beetles (Coleoptera, Hydrophilidae) (Hoe & Wong 2016, Hoe et al 2018). The anthetic duration is relatively short, 25‐29h, and starts at dawn between 04:00 – 05:30 h. Pollinator attraction is mainly dependent on floral semiochemicals (ester compounds).…”

“…sp. nov., and in those reported in previous studies (Hoe & Wong 2016, Hoe et al 2018). However, the significant temperature increment in the pistillate and sterile zones is unique and so far has not been detected in other species of the Calyptrata Clade.…”

Review of the flower-inhabiting water scavenger beetle genus Cycreon (Coleoptera, Hydrophilidae), with descriptions of new species and comments on its biology

“…For example, various genera and species of Schismatoglottideae were sampled in Mulu National Park (Malaysia, Sarawak) from December 2017 to February 2018, but Cycreon beetles were only found in sampled species of Schismatoglottis (beetles were present in all sampled plants), whereas not a single specimen was found in inflorescences of Anadendrum, Aglaonema, Alocasia, Bucephalandra and Lasia. Additionally, the material collected from various inflorescences of the single aroid tribe Schismatoglottideae by Low et al (2014Low et al ( , 2016, Hoe & Wong (2016) and Hoe et al (2018) includes two very closely related subspecies only (Cycreon floricola floricola and C. floricola borneanus), despite consisting of more than 1000 specimens; not a single specimen of another Cycreon species was collected even in peninsular Malaysia, despite the sampled localities were close to those of two other species (C. armandi and C. adolescens). We suppose this may be caused by the focus on a single narrow group of host plants, and is congruent with the expected species-specific host preferences in Cycreon beetles.…”

“…Most of the megasternine species are associated with various kinds of decaying organic matter, like mammal dung (e.g., Smetana 1978, Ryndevich 2008, Ryndevich et al 2017, Arriaga-Varela et al 2017, humid forest leaf-litter (e.g., Deler-Hernández et al 2015;Fikáček et al 2009;Fikáček and Short 2006) or rotten seaweed (e.g., Smetana 1978;Ryndevich 2001). In contrast to this general pattern, few genera are known to inhabit the interior of various inflorescences: the Neotropical Pelosoma Mulsant has been collected inside Heliconia flowers (Archangelsky 1997), and the Neotropical Nitidulodes Sharp and Oriental Cycreon Orchymont, 1919 were recently reported to be associated to Araceae flowers (Bloom et al 2014;Low et al 2016;Hoe and Wong 2016;Hoe et al 2018). However, very little is known about the biology and the systematics of these genera.…”

“…Extensive sampling of insects associated with inflorescences of Malayan aroid plants was performed recently by Low et al (2014Low et al ( , 2016, Hoe and Wong (2016) and Hoe et al (2018) in order to study their pollination biology, and Takizawa (2010) in order to study the association of species of Chaloenus Westwood, 1861 (Chrysomelidae) with these inflorescences. As a result, a high number of Cycreon specimens from both Peninsular Malaysia and Borneo was accumulated.…”