Butterfly-wing pollination inScadoxusand other South African Amaryllidaceae

Abstract

Understanding the evolution of floral morphology requires information about the identity of pollinators as well as the specific mechanisms of pollen transfer. Based on preliminary field observations and floral structure, we hypothesized that pollination mechanisms involving the transfer of pollen on butterfly wings occur in several lineages of South African Amaryllidaceae. Here we report findings from a detailed study of butterfly-wing pollination in two subspecies of Scadoxus multiflorus and review the prevalence of this pollination mechanism among other Amaryllidaceae in southern Africa. We established that S. multiflorus subsp. katherinae is genetically self-incompatible and thus entirely reliant on pollinators for seed production. We determined that this subspecies is pollinated almost exclusively by large swallowtail butterflies, principally males of the mocker swallowtail Papilio dardanus cenea. Flowers of S. multiflorus subsp. multiflorus are pollinated by pierid and swallowtail butterflies. Pollen is deposited on the ventral surface of the wings of butterflies as they flutter over the strongly exserted stamens. We predict that butterfly-wing pollination occurs in at least nine species of South African Amaryllidaceae, which may reflect several independent origins of this mechanism. The flowers of these species are red or orange with strong herkogamy and are either bowl-brush or open-brush in shape. We provide maps of the distribution of pollen on the ventral surface of the wings of pollinators for four of these species. All four appear to be pollinated via the ventral surface of large butterfly wings, with the floral structure facilitating the process. These findings illustrate the importance of investigating pollen transfer mechanisms in order to understand patterns of floral diversification and floral convergence.

Seed dispersal by monkey spitting in Scadoxus (Amaryllidaceae): Fruit selection, dispersal distances and effects on seed germination

“…Scadoxus multiflorus subspecies katherinae (Baker) Friis & Nordal inhabits swampy areas surrounding streams within coastal forests in eastern Africa. Inflorescences are up to 1.5 m in height and have conspicuous bright red flowers arranged in a lax ball shape, which are pollinated by butterflies (Butler & Johnson 2020). Fruits ripen slowly over 4 months and change from green, through yellow to red in colour.…”

“…These radii were chosen as they represent the maximum that was practically feasible for searching given that the leaf layer on the forest floor makes searching for seeds exceptionally laborious. For S. puniceus , the number of seeds per plant was counted before dispersal, and for S. multiflorus , they were estimated from the mean number of fruits per plant in the population (Butler & Johnson 2020). The number of seeds per plant found within the search radius was then subtracted from the initial number of seeds recorded (or estimated) for that plant, and this number was determined to be the number of seeds that had been potentially dispersed further than the search radius.…”

Micromorphology and Anatomy of the Flowers in Clivia spp. and Scadoxus multiflorus (Haemantheae, Amaryllidaceae)

“…(Funnell, 2008). e results of butterfly-wing pollination in two subspecies of S. multiflorus and a review of the prevalence of this pollination mechanism among other Amaryllidaceae in Southern Africa was recently published (Butler & Johnson, 2020). Karyotypic features include organizations of the 5S and 45S rDNA loci, telomeres of S. multiflorus (Monkheang et al, 2016), and tracking biological footprints of climate change using the flowering phenology of the geophytes in Pancratium tenuifolium and S. multiflorus (Kwembeya, 2021).…”

Reconstructing Great Basin Butterfly-Pollen Interaction Networks over the Past Century

“…While butterflies are foraging for nectar with their elastic proboscis, pollen grains stick to their eyes, proboscis, frons, antennae, wings, and legs, which renders them as pollen carriers and potential pollinators (Willmer, 2011). Identification and quantification of the pollen grains found on the bodies of butterflies or other pollinators can provide information about the plants that an individual has come into contact with and can be used to create plant-pollen networks for various inferences, including assumptions that these networks estimate pollination networks (Butler & Johnson, 2020). Although the presence of pollen on insects is an imperfect indicator of which plants the insect provides pollination services to, it suggests an interaction with the reproductive floral parts of that species (Jennersten, 1984;Butler & Johnson, 2020).…”

“…Identification and quantification of the pollen grains found on the bodies of butterflies or other pollinators can provide information about the plants that an individual has come into contact with and can be used to create plant-pollen networks for various inferences, including assumptions that these networks estimate pollination networks (Butler & Johnson, 2020). Although the presence of pollen on insects is an imperfect indicator of which plants the insect provides pollination services to, it suggests an interaction with the reproductive floral parts of that species (Jennersten, 1984;Butler & Johnson, 2020). This method may provide an insightful alternative to the visitation networks that dominate the pollination network literature (Silberbauer et al, 2004;Kleijn & Raemakers, 2008;Jones, 2012;Scheper et al, 2014) since insects in visitation networks can include parasites and incidental visitors that are not picking up or transferring pollen (Ballantyne et al, 2015).…”