Unveiling the History of a Peculiar Weevil-Plant Interaction in South America: A Phylogeographic Approach to Hydnorobius hydnorae (Belidae) Associated with Prosopanche americana (Aristolochiaceae)

Abstract

Interspecific interactions take place over both long and short time-frames. However, it is not completely understood if the interacting-partners persisted, migrated, or expanded in concert with Quaternary climate and landscape changes. We aim to understand whether there is concordance between the specialist weevil Hydnorobius hydnorae and its parasitic host plant, Prosopanche americana in space and time. We aim to determine whether Prosopanche had already established its range, and Hydnorobius later actively colonized this rare resource; or, if both host plant and herbivore expanded their range concomitantly. We performed population genetic, phylogeographic and Bayesian diffusion analysis of Cytochrome B sequences from 18 weevil localities and used paleodistribution models to infer host plant dispersal patterns. We found strong but uneven population structure across the range for H. hydnorae with weak signals of population growth, and haplotype network structure and SAMOVA groupings closely following biogeographic region boundaries. The ancestral areas for both Hydnorobius and Prosopanche are reconstructed in San Luis province within the Chaco Biogeographic province. Our results indicate a long trajectory of host-tracking through space and time, where the weevil has expanded its geographic range following its host plant, without significant demographic growth. We explore the past environmental changes that could underlie the boundaries between locality groups. We suggest that geographic dispersal without population growth in Hydnorobius could be enabled by the scarcity of the host plant itself, allowing for slow expansion rates and stable populations, with no need for significant demographic growth pulses to support range expansion.

Evolutionary history and colonization patterns of the wing dimorphic grasshopper Dichroplus vittatus in two Argentinean biomes

“…Several works suggested that terrestrial Patagonian taxa and some aquatic species probably survived glacial periods in southern refugia or alternatively recolonized the area from northern latitudes 56 – 59 . Recent studies revealed insights about the survival areas during glaciation periods in species distributed in non-glaciated Argentine plains 16 – 18 , 60 . Lately was proposed a suitable refuge area for populations of an endemic shrub towards the north of the 35° south latitude of Central Argentina during Pleistocene glaciations and a southeast direction of the range expansion during interglaciations 17 .…”

Phylogenetic and comparative analyses of Hydnora abyssinica plastomes provide evidence for hidden diversity within Hydnoraceae

“…The family Hydnoraceae consists of the two genera Hydnora [ 16 ] and Prosopanche [ 17 ]. The former being distributed from Southern Africa to the Arabian Peninsula and Madagascar, the latter from South to Central America [ 18 , 19 ]. This holoparasitic family of root parasites is among the oldest parasitic angiosperm lineages [ 20 ], and places within the magnoliid order Piperales.…”

Prosopanche: A remarkable genus of parasitic plants

“…Some Prosopanche are harvested and sold for their edible fruits, or their rhizomes, which are purported to have anti-asthmatic properties or are used as an expectorant (Cocucci, 1965;Cocucci & Cocucci, 1996).The last comprehensive of monograph of Prosopanche was written in 1965 by A. Cocucci, in which he concluded there were just two species in the genus. Recent work has focused on their ecology, for example, interactions between Prosopanche and the associated specialist Hydnorobius weevils that interact with them (Ferrer & Marvaldi, 2010;Sequeira et al, 2018), or the discovery of new species; otherwise, Prosopanche has received very little attention in the literature in the last 60 years (de Carvalho et al, 2021). Furthermore, Prosopanche has never been cultivated outside of its native range (Thorogood et al, 2022).…”