Species

BackHomoeodera edithia Wollaston, 1877

Homoeodera edithia Wollaston, 1877

Edith’s Fungus Weevil (English)

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

Countries of Occurrence:
Saint Helena - British Overseas Territory

Archipelago(s):
St. Helena

Assessor/s:
Pryce, D. & White, L.

Reviewer/s:
Gerlach, J.

Contributor/s:

Facilitators / Compilers/s:


Assessment Rationale:

 This is clearly a rare species. It has been found at three locations most often in association with the dead wood of unspecified endemic 'Cabbage Tree' species of the family Asteracea, it has also been found occasionally in Gorse (Ulex europaeus L.) and Smokebush Buddleja (Buddleja madagascariensis Lam.). The She Cabbage Trees (Lachanodes arborea (Roxb.) B.Nord.) with which it was associated at one of its three locations have been lost and it is not known if it has been able to persist in non-native vegetation at this location. The species has not been seen since May 1967. It has an extent of occurrence (EOO) and area of occupancy (AOO) both of 8 km² and the population is considered severely fragmented. While this species belongs to a group of invertebrates specifically targeted by a recent survey (Mendel, Ashmole and Ashmole, 2008) and was not found at this time, it does appear to have a requirement for dead wood in a particular rot state that may not have been met with during the survey and it could well still persist. The species is therefore assessed as Critically Endangered.

Geographic Range:

 Endemic to the island of St Helena, in the South Atlantic Ocean, where it is found at middle and upper elevations

Regions:
Portugal - Azores
Extent of Occurrence (EOO):
8 (km2)
Area of Occupancy (AOO):
8 (km2)
Elevation Lower Limit:
610 (m)
Elevation Upper Limit:
792 (m)
Biogeographic Realms:
South Atlantic Ocean
Presence:
Extant
Origin:
Endemic St. Helena
Seasonality:
Resident

Population:

 This species was described from a single specimen collected in 1875-6 (Wollaston 1877). During the two Belgian expeditions of the mid- to late 1960s it was found at three locations: the High Central Ridge, High Peak and at Rural Retreat Gut (Basilewsky 1972); at this time there were endemic She Cabbage Trees (Lachanodes arborea (Roxb.) B.Nord.) still present at the last site which have since been lost. The species was not found during the last major survey of its habitat (Mendel, Ashmole and Ashmole 2008), despite this group of beetles being a particular target of the research; however environmental conditions (seasonality) could explain this. With a general decline in habitat quality and an increase in the number of invasive non-native predators (e.g. Formicidae) it is inferred that this species is declining in numbers.

Habitat and Ecology

 This species is primarily associated with the dead wood of unspecified endemic 'Cabbage Tree' species of the family Asteraceae, and in particular with the fungi associated with this material; more than 87% of specimens have been collected specifically from this material. The only specified host plants material has been the rotting wood of a She Cabbage Tree (Lachanodes arborea (Roxb.) B.Nord.) - 6% of specimens; dead wood of non-native Gorse (Ulex eropaeus L.) - 6% of specimens, and the rotting trunk of non-native Smokebush Buddleja (Buddleja madagascariensis Lam.) - 0.6% of specimens (Basilewsky 1972).

Major Threat(s):

 There has been a general decline in habitat quality and the loss of one of its endemic host plants at one location. There is an increase in the number of invasive non-native predators (e.g. Formicidae). Global warming is also a potential threat to habitat quality with an increasing risk of extreme climatic events occurring.

Conservation Actions

 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.