Coextinction is magnifying the current extinction crisis, as illustrated by the eriophyoid mites and their host plants

Abstract

Coextinction is a major and growing threat to global biodiversity. One of the affected groups is the eriophyoid mites (Prostigmata: Eriophyoidea) which are highly host plant specific. They have been described from an enormous range of annual and perennial plants from grasses to giant forest trees. It is highly likely that there are huge numbers of undescribed eriophyoid species in the subtropical and tropical regions which harbor an extraordinary wealth of plant diversity. The global total of eriophyoid species is estimated to be at least 250,000 but it could be much higher. However, the continuing destruction and degradation of natural habitat, especially tropical forests, and climate change, together pose extreme, on-going threats to the eriophyoid mites because of their vulnerability to co-extinction with their host plants. It has been reported that one third of all the Earth’s plant species are now at risk of extinction. Together with enormous numbers of other invertebrate species, it is highly likely that many thousands of eriophyoid species are disappearing in the current mass extinction event. Population decline and co-extinction, especially of the invertebrates, are greatly accelerating total biodiversity losses. The termination of habitat destruction and degradation; establishment of large, representative protected areas; restoration of degraded areas; and rapid reduction of fossil fuel use, are urgent tasks. However, the long term conservation of biodiversity can only be achieved through comprehensive social, economic and political reforms across the world that prioritize environmental protection, peaceful coexistence, social justice and the sustainable use of resources.

Pest categorisation of Setoptus parviflorae

“…Most eriophyoid mite species, are closely linked to one or a small number of hosts (Ozman‐Sullivan & Sullivan, 2023). In the case of species belonging to the genus Setoptus , they are highly specific on plants of the genera Pinus or Tsuga .…”

Global patterns of the species richness and distribution of eriophyoid mites: a response to Li et al. 2023

“…The tropical rainforest arthropods, including mites, are the one of the most species‐rich groups of eukaryotic organisms on Earth (Basset et al, 2012). Most mite species are expected to inhabit tropical regions (Basset et al, 2012, 2015; Ozman‐Sullivan & Sullivan, 2023; Stanton, 1979; Stork, 2018; Sullivan & Ozman‐Sullivan, 2021, 2022; Tixier & Kreiter, 2009; Walter, 2001; Walter & O'Dowd, 1995; Walter & Proctor, 1998; Walter et al, 1994, 1998).…”

“…Sullivan and Ozman‐Sullivan (2021) estimated that there are 240,000 extant eriophyoid species, based on an estimate of 300,000 plant species worldwide (Cowan et al, 2006), and have since revised that estimate upward to at least 250,000 species (Ozman‐Sullivan & Sullivan, 2023), based on 320,000 described plant species (Christenhusz & Byng, 2016). Ozman‐Sullivan and Sullivan (2023) further stated that the actual number of eriophyoid species may be much higher because numerous host plant species have two or more eriophyoid species associated with them, and because Pimm and Joppa (2015) estimated the total number of plant species to be 450,000.…”

“…Moreover, most plant species are endemic to the tropics (Cazzolla Gatti et al, 2022; Christenhusz & Byng, 2016; Pimm & Joppa, 2015). For example, based on a checklist of eriophyoid mite species and their host plants in Brazil (Navia et al, 2021), Ozman‐Sullivan and Sullivan (2023) estimated that less than 1% of its plant species have been investigated for their eriophyoid mite fauna, based on Martins et al (2017) reporting of more than 35,000 plant species in Brazil. Projecting from the 234 eriophyoid species listed from just 233 plant species by Navia et al (2021), there may be 28,000 or more eriophyoid species in Brazil alone.…”

“…Most flowering plant species host at least one eriophyoid species (Fenton, 2002) and new eriophyoid taxa can be easily collected, especially on endemic, rare or non-economically important host plants (Chetverikov et al, 2021). Plant diversity is extremely high in tropical environments (Cazzolla Gatti et al, 2022;Christenhusz & Byng, 2016;Pimm & Joppa, 2015), so a huge number of undescribed eriophyoid species can be expected to be associated with them (Amrine et al, 2003;Fenton, 2002;Lindquist, 2001;Navia et al, 2021;Ozman-Sullivan & Sullivan, 2023;. Li et al (2023) reported that they conducted an analysis of the global patterns and drivers of eriophyoid mite diversity.…”