05 August, 2021

Plant phylogeny as a major predictor of flower visitation by nitidulid beetles, a lineage of ancestral angiosperm pollinators

by Carlos M. Herrera and J. Carlos Otero

Two individuals of Brassicogethes aeneus (Nitidulidae)
on flowers of
Sisymbrium crassifolium (Brassicaceae)

Beetles are considered the ancestral, oldest pollinators of animal-pollinated plants, and they pollinate many extant species all over the world. Little is known, however, on which factors explain the broad differences among plant species in prevalence of beetle pollination. We studied differences among plant species in flower visitation by “pollen beetles” of the family Nitidulidae, using quantitative pollinator data for 251 plant species from well-preserved montane habitats in southeastern Spain. Nitidulids were recorded in flowers of 25% of the species considered, their distribution being clustered on certain plant lineages (Ranunculales, Malvales, Rosales, Asterales) and remarkably absent from others (Fabales, Lamiales). None of the environmental or macroscopic floral features considered predicted nitidulid visitation, thus revealing that plant phylogeny was the single best predictor of nitidulid pollination in the plant communities studied.

Read the scientific publication in JPE.

04 August, 2021

Testing for apomixis in an obligate pollination mutualism

 by Jonathan T.D. Finch, Sally A. Power, Justin A. Welbergen and James M. Cook

A) The “coffee bush” Breynia oblongifolia
(Phyllanthaceae) in Richmond, NSW, Australia
B) female flowers C) male flowers with
enclosed stigmas and D) mature fruits.
Many Plants with a small number of specific pollinators may be vulnerable to fluctuations in the availability of those pollinators, which could result in pollination failure. Plants can develop mechanisms to mitigate the risk of pollination failure, such as apomixis. Apomixis is the clonal reproduction of plants through seeds without pollination or fertilisation.

We performed a flower-bagging experiment to test if the unisexual flowers of Breynia oblongifolia (Phyllanthaceae) could set fruit in the absence of its highly specialised seed-eating moth pollinators. Surprisingly, many bagged female flowers developed fruits, suggesting apomixis.

Read the whole summary in English.

Read the scientific publication in JPE.