IUCN SSC Mid-Atlantic Island Invertebrates Specialist Group

Species

BackAtheta dryochares Israelson, 1985

Atheta dryochares Israelson, 1985

Rove beetle (English); Escaravelho-de-asa-curta (Portuguese)

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Insecta
  • Order: Coleoptera
  • Family: Staphylinidae
NT Near Treatened
IUCN Red List Status:

Countries of Occurrence:
Portugal - Azores

Archipelago(s):
Azores

Reviewer/s:
Danielczak, A.

Contributor/s:

Facilitators / Compilers/s:


Assessment Rationale:

Atheta dryochares is an endemic species present in Faial, Pico, Graciosa, São Jorge, Terceira, S. Miguel and Sta. Maria islands (Azores, Portugal). It has a relatively large extent of occurrence (EOO = 25,220 km²) but a small area of occupancy (AOO = 104 km²). However, the AOO is overestimated since the real size of native forest fragments is 40 km². The species occurs in medium and high altitude in hyper-humid pristine forests associated with the canopy of endemic trees. Based upon the number of locations that have ongoing threats it is assessed as Near Threatened.

Geographic Range:

Atheta dryochares is an endemic species present in Faial, Pico, Graciosa, São Jorge, Terceira, S. Miguel and Sta. Maria islands (Azores, Portugal) (Borges et al. 2010; Borges, unpublished data), known in Natural Forest Reserves of Caldeira do Faial (Faial), Caveiro and Mistério da Prainha (Pico), Topo (São Jorge), Biscoito da Ferraria, Pico Galhardo, Caldeira Sta. Bárbara e Mistérios Negros and Terra Brava (Terceira); Pico da Vara, Atalhada and Graminhais (S. Miguel); and Pico Alto (Sta. Maria). The extent of occurrence (EOO) is ca 25,000 km² and the maximum estimated area of occupancy (AOO) is 104 km².

Regions:
Portugal - Azores
Extent of Occurrence (EOO):
25000 (km2)
Area of Occupancy (AOO):
104 (km2)
Elevation Lower Limit:
400 (m)
Elevation Upper Limit:
1200 (m)
Biogeographic Realms:
Palearctic
Presence:
Extant
Origin:
Endemic Azores
Seasonality:
Resident

Population:

The species is particularly abundant in the canopy of endemic trees, and subpopulations are known in seven islands (Faial, Pico, Graciosa, São Jorge, Terceira, S. Miguel and Sta. Maria). The species presents a stable population. The habitat is protected and we assume no impact for the population.

Habitat and Ecology

This species occurs in native forests dominated by Ilex perado subsp. azoricaLaurus azoricaErica azoricaJuniperus brevifolia and Vaccinium cylindraceum, in the islands of Faial, Pico, São Jorge, Graciosa, Terceira, S. Miguel and Sta Maria (Azores). This species has an altitudinal range between 400 and 1200 m. It is a predator that lives under bark, and is associated with lichens and bryophytes of endemic trees, being active during the night. Based on seasonal data from SLAM traps obtained in several islands between 2012 and 2016, the adults are active all year, being most abundant in spring and summer (Borges et al. 2017).

Major Threat(s):

In the past, the species has probably strongly declined due to changes in habitat size and quality (Triantis et al. 2010; Terzopoulou et al. 2015). Currently the most important ongoing threats to this species are Cryptomeria japonica wood & pulp plantations management and the spread of invasive plants namely Pittosporum undulatumClethra arboreaand Hedychium gardnerianum since are changing the habitat structure, namely decreasing the cover of bryophytes and ferns in the soil and promoting the spread of other plants. Based on Ferreira et al. (2016) the habitat will further decline as a consequence of climate change (increasing number of droughts and habitat shifting & alteration).

Conservation Actions

The species is not protected by regional law. Its habitat is located in regionally protected areas (Natural Parks of Faial, Pico, São Jorge, Terceira, S. Miguel and Sta. Maria). Degraded habitats should be restored and a strategy needs to be developed to address the future threat by climate change. Formal education and awareness is needed to allow future investments in restore habitats invaded by invasive plants. Further research is needed into its ecology and life history in order to find extant specimens in another islands and obtain information on population size, distribution and trends. It is also necessary a monitoring plan for the invertebrate community in the habitat in order to contribute to perform a species potential recovery plan in some islands where invasive plants are changing habitat structure. A monitoring every ten years using the BALA protocol will inform about habitat quality (see Gaspar et al. 2011).