Countries of Occurrence:
Portugal - Azores
Facilitators / Compilers/s:
Phthiracarus falciformis is an endemic species of the Azores (Portugal), having been described from one coastal lava tube (Gruta das Agulhas) in Terceira island. From the species' description, it has a very small Extent of Occurrence (4 km2 ) and Area of Occupancy (4 km2 ). However, these are likely to be underestimates, as this species probably has a wider distribution through the soil component of the island. 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 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, this species is assessed as Data Deficient (DD).
Phthiracarus falciformis is an endemic oribatid mite species known from Terceira island (Azores, Portugal) (Borges et al. 2010), having been described from the coastal lava tube of Gruta das Agulhas. From the species' description, the Extent of Occurrence (EOO) is ca. 4 km² and the minimum estimated Area of Occupancy (AOO) is 4 km².
No current population size estimates exist for this species. As an oribatid mite, this species in likely common and widespread in the soil habitat. Current Population Trend: Unknown
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). Phthiracarus falciformis was collected from the entrance of a coastal lava tube, but according to Morell and Subias (1991), oribatid mites are soil species and should not be considered as strictly cave species. This species is likely an eutroglophile (epigean species able to maintain a permanent subterranean population) (Borges et al. 2012). Systems: Terrestrial
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, urbanisation, pesticides and nutrient loads or invasive plants might also affect this species.
The species is not protected by regional law and Gruta das Agulhas is not a protected site. 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. Further research is needed into its population, distribution, threats, ecology and life history; and a monitoring plan for the invertebrate community is necessary in order to contribute to the conservation of this species.