Assessment Rationale:

This species is present at four locations on the outermost fringe of the island where it is associated with the endemic Scrubwood (Commidendrum rugosum (Dryland) DC.) (Clark and Benoit 1977; Mendel, Ashmole and Ashmole 2008). The habitat quality is certainly declining at two of the sites (Turk's Cap and Great Stone Top) as a result of alien invasive plants (e.g. Schinus terebrinthfolius Raddi) being spread in bird faeces; and at another site (Blue Point) continued habitat quality is dependent ongoing conservation work. Invasive, non-native predatory species will also be putting pressure on this species by competing with it as well as by direct predation. The species is also judged to be severely fragmented as a result of the fragmented nature of its habitat. It has an extent of occurrence of 44 km² and is therefore, assessed as Critically Endangered

Geographic Range:

Endemic to the island of St Helena where it occurs in the east and far south of the island; all four sites are within one kilometre of the coastline

Population:

Habitat quality at two sites (Signal House cliff top Scrubwood site and Great Stone Top) is decreasing due to the spread of alien invasive plant species arriving as seed in bird droppings; these sites are also very difficult to access. The habitat quality at Blue Point is dependent on continued conservation work and would deteriorate rapidly if this ceased. Several invasive, non-native predatory species including the spider Xeropiger tridentiger(Pickard-Cambridge, 1869) and the centipede Scolopendra morsitans Linnaeus, 1758 will also be adding pressure to the species by competition for resources as well as potential direct predation. It is therefore inferred that the population of this species is declining

Habitat and Ecology

This species is restricted to the arid outer fringes of the island. Three of its sites are classified as desert, the fourth is low mixed scrub surrounded on three sides by desert. Endemic Scrubwood (Commidendrum rugosum (Dryland) DC.) is present at all four sites and St Helena Tea Plant (Frankenia portulacifolia (Roxb.) Spreng.) is also present at the Turk's Cap site. The precise relation of the spider to the plants is unknown but it is speculated that it may be a specialist predator on one of the herbivorous species associated with these plants such as the planthopper 'Atlantisia' leleupi Dlabola, 1977 (currently in need of a replacement generic name)

Major Threat(s):

Habitat quality at two sites is decreasing due to the spread of alien invasive plant species arriving as seed in bird droppings; these sites are also very difficult to access for maintenance. The habitat quality at Blue Point is dependent on continued conservation work and would deteriorate rapidly if this ceased. Several invasive, non-native predatory species including the spider Xeropigo tridentiger (Pickard-Cambridge, 1869) and the centipede Scolopendra morsitans Linnaeus, 1758 will also be adding pressure to the species by competition for resources as well as potential direct predation

Conservation Actions

Research should be undertaken to identify the precise habitat requirements of this species; indeed any research and monitoring of it would be of value