Countries of Occurrence:
Saint Helena - British Overseas Territory
Pryce, D. & White, L.
Facilitators / Compilers/s:
This scarce insect is restricted to the highest portion of the island where it is believed to be associated with two species of endemic fern (Dicksonia arborescens L'Hér. and Diplazium filamentosum (Roxb.) Cronk). It appears to be declining and was not found during the most recent survey of this area (Mendel, Ashmole and Ashmole 2008), despite this being a group particularly targeted by the research. Although it has not been seen since March 1967 the species is from an obscure and poorly studied family of beetles and could well still be present. It has an extent of occurrence (EOO) and area of occupancy (AOO) of 8 km² and the population is considered to be severely fragmented. Therefore, it is assessed as Critically Endangered
Endemic to the island of St Helena, in the South Atlantic Ocean, where it is confined to the upper parts of the High Central Ridge
The species was scarce when first found by Wollaston in 1875; he found it at Diana’s Peak, Mount Actaeon and High Peak (Wollaston 1877). It was found to be very scarce during the two expeditions by the Royal Museum for Central Africa in 1965-6 and 1967 with four specimens found along the High Central Ridge and one at Cabbage Tree Road (Basilewsky 1972). No specimens were encountered during the Peaks survey of 2005-6 (Mendel, Ashmole and Ashmole 2008). Taking into account the relative survey efforts and current declines in habitat quality it is inferred that the population is declining
This species has been swept from Tree Fern (Dicksonia arborescens L'Hér.) and Black Scale Fern (Diplazium filamentosum (Roxb.) Cronk) in cloud forest on the High Central Ridge of the island. The larvae presumably feed in the dead wood of these species and the adults on decaying plant matter and associated unidentified fungi. The species is flightless so presumably not an efficient disperser
There has been a general decline in habitat quality and an increase in the number of invasive non-native predators (e.g. Formicidae). Global warming is also a potential threat to habitat quality
Any research and monitoring of this species would be of value. Of critical importance is the continued expansion and linking of habitat fragments as well as removal of invasive non-native species where this is possible.