MAIISG

Assessment Rationale:

Homoeosoma picoensis is a single island endemic species restricted to Pico island (Azores, Portugal) (Borges et al. 2010). It has a very small extent of occurrence (EOO = 4 km²) and area of occupancy (AOO = 4 km²). There is a continuing decline in the EOO, AOO, extent and quality of habitat as well as the number of mature individuals as a result of major land-use change in the last 100 years and recent intensification in cattle production. Main recent past and ongoig threats are the invasive plants Pittosporum undulatum and Hedychium gardnerianum that are changing the habitat. Based on Ferreira et al. (2016) the habitat will decline as a consequence of climate change. Based upon the small geographic range of the species with only one location and continuing decline of its habitat area and quality, it is assessed as Critically Endangered.

Geographic Range:

Homoeosoma miguelensis is a single island endemic species restricted to S. Miguel island (Azores, Portugal) (Borges et al. 2010). It possibly lives in native vegetation in the Natural Forest Reserve of Pico da Vara and surrounding fragmented areas (e.g., Povoação at 300m asl; Meyer et al. 1997). The extent of occurrence (EOO) is 20 km² and the maximum estimated area of occupancy (AOO) is 20 km².

Population:

Homoeosoma miguelensis is possibly scattered and low abundant in S. Miguel island, occurring mostly in native vegetation but also in naturalized plants.

Habitat and Ecology

Preferably, the species occurs in areas of native forest, and fragmented areas of the surroundings; the larvae are supposed to feed on the Asteraceae plants. We assume that this species is a specialist herbivore, and flies in July at medium altitudes of the Povoação (Meyer et al. 1997). Altitudinal range: 200-600 m.

Major Threat(s):

In the past, the species has probably strongly declined due to changes in habitat size and quality, mostly the creation of pastures and Cryptomeria japonica plantations (Triantis et al. 2010). Currently invasive plants Pittosporum undulatum and Hedychium gardnerianum are changing some of the areas and decreasing the quality of the habitat. 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 in regionally protected areas (Natural Park of S. Miguel). Further research is needed into its ecology and life history in order to find extant specimens. Degraded habitats should be restored and a strategy needs to be developed to address the future threat by climate change. It is necessary a monitoring plan for the invertebrate community in the habitat in order to contribute to the conservation of this species. A habitat management plan is needed and anticipated to be developed during the coming years. Monitoring every ten years using the BALA protocol will inform about habitat quality (see e.g. Gaspar et al. 2010)