Assessment Rationale:

Megaselia miguelensis is an Azorean-endemic eutroglophile species known from a single island, S. Miguel (Azores, Portugal). It has a very small Extent of Occurrence (EOO = 4 km²) and Area of Occupancy (AOO = 4 km²). The species is very rare and only known from a single subpopulation in a single cave; with the area surrounding the cave being heavily impacted by human activities. 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. A habitat management plan is needed and one is anticipated to be developed during the coming years. We also suggest as future conservation measures the regular monitoring of the species and fencing the entrance of the cave where the species occurs. The species is assessed as Critically Endangered (CR). 

Geographic Range:

Megaselia miguelensis is single island endemic species known from S. Miguel island (Azores, Portugal) (Borges et al. 2010), occurring in only one lava tube cave (Gruta da Agua de Pau). The species can also potentially occur in the surrounding environment. The Extent of Occurrence (EOO) is 4 km² and the maximum estimated Area of Occupancy (AOO) is 4 km².

Population:

The species is very rare and only known from a single subpopulation in S. Miguel island. The area surrounding the cave is heavily impacted by human disturbance.

Current Population Trend: Decreasing

Habitat and Ecology

The ecology and traits of this species are unknown. Phorids are usually found in damp habitats, in the presence of different kinds of decomposing plant and animal matter, including human corpses (hence the name coffin flies), on flowers and fungi or on ant nests and beehives, among others. Larvae, besides being found in the aforementioned habitats can also be found in faeces, in gastropods, as internal parasites of other arthropods, or as parasites or commensals of ants and termites (McAlpine et al. 1987). Most adults feed on nectar or on the liquids exuded by carrion and dung. Some species can be a vector of food contamination. Some species of the genus Megaselia feed and develop on fungi and are considered pests of cultivated mushrooms, while others develop in decaying material organic material, trash and sewers or on carrion. Megaselia miguelensis is an eutroglophile species (i.e. epigean species able to maintain a permanent subterranean population), being known from only one lava tube.

Systems: Terrestrial 

Major Threat(s):

The main current threats to this species are the degradation of habitat quality, due to urbanisation and construction, and recreational cave visitation. However, there are several future potential threats: climatic changes (Ferreira et al. 2016) that can change the conditions inside the cave, but also changes in the nearby infrastructures, potential human recreational activities with cave visitation, and geological events (volcanic activity and earthquakes). 

Conservation Actions

This species is not protected by regional law. The present situation of this species needs to be assessed and further research is needed into its population, distribution, threats, ecology and life history. A monitoring plan for the invertebrate community is necessary in order to contribute to the conservation of this species. As a future conservation measure, the creation of a fence in the entrance of the cave could be considered. A habitat management plan is needed and one is anticipated to be developed during the coming years.