BackHeminothrus oromii Morell & Subías, 1991

Heminothrus oromii Morell & Subías, 1991

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Arachnida
  • Order: Acari: Oribatida
  • Family: Camisiidae
DD Data Deficient
IUCN Red List Status:

Countries of Occurrence:
Portugal - Azores




Facilitators / Compilers/s:

Assessment Rationale:

Heminothrus oromii is an endemic species of the Azores (Portugal), being described from a few locations in Terceira and S. Miguel islands. From the species' description, it potentially has a very small Extent of Occurrence (197 km2 ) and Area of Occupancy (16 km2 ), but these are are likely underestimates, as this species probably has a wider distribution through the soil component of the islands. It can be assumed that this species is affected by human activities and invasive plant species that alter the natural structure and composition of the soil. Future climatic changes and increased risk of droughts will also affect this species. The present situation of this species needs to be further assessed and further research is needed into its population, distribution, threats, ecology and life history; while conservation of natural habitats and invasive species control could potentially aid this species' conservation. Based upon the incomplete knowledge regarding this species' population, distribution, threats and ecology, it is not possible to accurately estimate the extinction risk of the species and it could theoretically fall into any category. Therefore, this species is assessed as Data Deficient (DD).

Geographic Range:

Heminothrus oromii is an Azorean endemic oribatid mite species known from Terceira and S. Miguel islands (Azores, Portugal) (Borges et al. 2010), being described from two sites in the Nature Reserve of Caldeira Sta. Bárbara e Mistérios Negros in Terceira, and from the Natural Forest Reserve of Pico da Vara (Tronqueira) in S. Miguel. From the species' description, the Extent of Occurrence (EOO) would be ca. 197 km² and the Area of Occupancy (AOO) would be 16 km².

Portugal - Azores
Extent of Occurrence (EOO):
197 (km2)
Area of Occupancy (AOO):
16 (km2)
Elevation Lower Limit:
Elevation Upper Limit:
Biogeographic Realms:
Endemic Azores


No current population size estimates exist for this species. As an oribatid mite, this species is possibly common and widespread in the soil habitat. Current Population Trend: Unknown.

Habitat and Ecology

The ecology and traits of this species are unknown. Oribatid mites are associated with organic matter in most terrestrial ecosystems, being found throughout the soil profile, in surface litter, on grasses, shrubs or in the bark and leaves of trees, among other habitats. Oribatida are also one of the most numerically dominant arthropod groups in the organic horizons of most soils (Behan-Pelletier 1999). Heminothrus oromii has been collected from native heathland and forest, but also from Calluna vulgaris and Cryptomeria japonica. Systems: Terrestrial.

Major Threat(s):

A lack of information regarding the present range of this species precludes an assessment of potential threats. Nevertheless, it can be assumed that this species will be affected by future habitat declines as a consequence of climate change (Ferreira et al., 2016) and increased droughts. Other factors that affect habitat quality like land use changes, pesticides and nutrient loads or invasive plants might also affect this species. The forest in Tronqueira is being degraded by the spread of invasive plants (Hedychium gardnerianum and Clethra arborea), which are changing the habitat and soil structure. 

Conservation Actions

The species is not protected by regional law, but part of its habitat is in regionally protected areas (Natural Parks of Terceira and S. Miguel). Invasive plants and land-use changes are likely one of the main current and future threats, and conservation of native habitats and invasive species control could potentially aid this species' conservation. The São Miguel Natural Park administration is currently starting control measures of the invasive plants. A LIFE PRIOLO project started with a restoration of degraded habitats increasing the area of pristine forest. A habitat management plan is needed and one is anticipated to be developed during the coming years. Further research is needed into its population, distribution, threats, ecology and life history; and it is necessary to develop a monitoring plan for the invertebrate community in order to contribute to the conservation of this species.