Assessment Rationale:

This species is believed to be restricted to the north of the Island of Tenerife, in the Canary Islands in Spain. It was described in the 1980s from the environments of the city of La Laguna, mainly in an agricultural area next to the University. The original area of the species had an extent of c. 16 km2 with two known locations. As yet there are no further records from outside the zone. In the intervening 30 years there has been a large reduction in the agricultural area next to the University. 

The species is assessed as Endangered (EN) under criteria B2ab(iii) based on the loss of habitat within the only known subpopulations on Tenerife, with inferred loss of mature individuals. M. Neiber (pers. comm. 2016) reported that he failed to locate the species in the known habitats during optimum sampling conditions in 2015. Since then Ibanez and Alonso resurveyed in February 2016 and failed again to locate the species. They plan further to repeat this survey in spring 2017 (M. Neiber pers. comm. 2016). Further research is urgently needed to establish the native status of the population, as well as the population trend and current distribution.

Geographic Range:

This species is believed to be restricted to the Canary Islands. It was described from north of Tenerife where it occurs in the environments of the city of La Laguna, mainly in agricultural areas next to the University. It was described from an area of c. 16 km2 with two known locations in the 1980s. There are no further records from outside the zone. The origin of the species is unknown. The situation of detection arises some doubts on the endemic status of the species which also might have been introduced from unknown origin.

Population:

The description was based on more than 180 specimens, so the species is supposed to be represented in high number in the field. M. Neiber (pers. comm. 2016) reported that he failed to locate the species in the known habitats during optimum sampling conditions in 2015. Since then, Ibáñez and Alonso resurveyed in February 2016 and failed to locate the species again. They plan further to repeat this survey in spring 2017 (M. Neiber pers. comm. 2016).

Habitat and Ecology

The species was detected in a rural, anthropogenic area nearby the city of La Laguna, and in autochtonous lowland shrub vegetation (Piso-Basal). The situation of detection arises some doubts on the endemic status of the species which also might have been introduced from unknown origin.

Major Threat(s):

There are no known threats to the species, although the slugs of this genus can become a pest species in agricultural fields. In the intervening 30 years since it was described there has been large reduction in the agricultural area next to the University, as it is converted for industrial and university use, and hence the habitats and area of occupancy (AOO) have significantly declined.

Conservation Actions

Research is urgently needed to establish the native status of the population, as well as the population trend and current distribution.