The Desertas wolf spider, is a critically endangered spider species endemic to the Deserta Grande Island of the Madeira archipelago .
Adult numbers have been estimated at less than 5,000, making it one of the rarest spider species. It is also believed to be one of the largest wolf spiders on earth, with a 12 cm leg span for the female, somewhat smaller for the male (the Latin ingens means “huge” or “monstrous”). Coloration is grey and black with white spots on the legs.
The spider hides under rocks and crevices on their volcanic island, but its habitat is being invaded by the grass Phalaris aquatica, while the native vegetation is damaged by introduced goats and rabbits. The spider preys on smaller relatives, millipedes and other insects. It is capable of delivering a painful and venomous bite to humans.
IUCN Red List status: Critically Endangered
The Desertas Islands in Portugal are the sole home of the Desertas wolf spider where it inhabits a single valley in the north of the Island which is currently invaded by a non-native grass. This invasive species competes with the native flora and was subject to several eradication experiments, namely through fire and chemicals. Based upon the small single geographic range of the species which is currently in decline it is assessed as Critically Endangered.
