IUCN SSC Mid-Atlantic Island Invertebrates Specialist Group


BackStenoptilia meyeri Gielis, 1997

Stenoptilia meyeri Gielis, 1997

Plume Moth

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Insecta
  • Order: Lepidoptera
  • Family: Pterophoridae
CR Critically Endangered
IUCN Red List Status:

Countries of Occurrence:
Portugal - Azores


Paulo A.V. Borges

Danielczak, A.

Nunes, R.

Facilitators / Compilers/s:

Assessment Rationale:

Stenoptilia meyeri is an endemic species of S. Miguel island (Azores, Portugal) (Borges et al. 2010). It has a very small Extent of Occurrence (EOO = 8 km²) and Area of Occupancy (AOO = 8 km²). Currently Stenoptilia meyeri is under threat due to degradation of its habitat caused by the invasive plants Hedychium gardnerianum and Clethra arborea, which are changing the habitat structure, decreasing the cover of bryophytes and ferns in the soil, and promoting the spread of other plants. Based upon the small range, decreasing quality of the habitat and it being restricted to a single subpopulation, this species is assessed as Critically Endangered (CR).

Geographic Range:

Stenoptilia meyeri is a single-island endemic species from S. Miguel island (Azores, Portugal) (Gielis 1997). This species occurs in the Natural Forest Reserve of Pico da Vara (S. Miguel). The Extent of Occurrence (EOO) is 8 km2 and the maximum estimated Area of Occupancy (AOO) is 8 km2.

Portugal - Azores
Extent of Occurrence (EOO):
8 (km2)
Area of Occupancy (AOO):
8 (km2)
Elevation Lower Limit:
700 (m)
Elevation Upper Limit:
1000 (m)
Biogeographic Realms:
Endemic Azores


The species is possibly rare and only known from a single subpopulation. A continuing decline in the number of mature individuals is inferred from the ongoing habitat degradation due to invasions of alien plants (Hedychium gardnerianum, Clethra arborea).

Habitat and Ecology

This is cloud forest species that occurs in the hyper-humid Azorean native forests, surrounded by plantations of exotic trees (Cryptomeria japonica), with an altitudinal range between 700 and 1,000 m. We assume that this species is a specialist herbivore, but with unknown current details on its ecology.

Major Threat(s):

The most important ongoing threat to this species is the spread of invasive plants (Hedychium gardnerianum and Clethra arborea), which 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 decline as a consequence of climate change (increasing number of droughts and habitat shifting and alteration), which may drive this species to extinction, because it is dependent on humid forests.

Conservation Actions

The species is not protected by regional law, but its habitat is in a regionally protected area (S. Miguel Natural Park). 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. Further research is needed into its ecology and life history in order to learn about the ecological requirements of the species and the feeding substrate of the larva; and further surveys and monitoring are required to clarify its population size, trends and distribution into other forest areas of S. Miguel island. An important first step in creating a potential specific species recovery plan is monitoring the entire invertebrate community of this habitat and creating an area-based management plan. Monitoring every ten years using the BALA protocol will inform about habitat quality (e.g. see Gaspar et al. 2011).