The Saint Helena earwig or Saint Helena giant earwig (Labidura herculeana) was a species of earwig endemic to the isolated island of Saint Helena, in the south Atlantic Ocean. It is now considered extinct.
This is the world’s largest known earwig, attaining a length of up to 80 mm. A total of 40 specimens were collected from the Horse Point area during the two Belgian expeditions from the Royal Museum for Central Africa in 1965-6 and 1967 (Brindle 1970). Live specimens were not found at any other sites at this time although they reported fragments of dead individuals from the south and east flanks of Flagstaff. There are a couple of unconfirmed records that the species was present after this time and it was thought to be declining. Two expeditions were conducted by Paul Pearce-Kelly from the London Zoo in 1988 and 1993, however, they failed to find any trace of the species. Recent intensive survey work in the 1990s and 2000s by Philip and Myrtle Ashmole failed to locate the species in this or nearby areas (Ashmole and Ashmole 2003). Howard Mendel from the Natural History Museum in London also failed to find it during a visit with the Ashmoles in 2005-6. The habitat at Horse Point has been degraded as far as this species is concerned since the time of the Belgian expeditions by the removal of nearly all surface stones, under which specimens were then found, for construction purposes. There has also been potential increased predator pressure from mice and rats, and probably also from invasive non-native predatory invertebrates including spiders and the centipede Scolopendra morsitans Linnaeus, 1758. The only possible evidence that this species may have persisted beyond the time of the Belgian expeditions has been the discovery of fragments of dead individuals. A sub-fossil forcep and ninth abdominal tergite was found with bird bones in 1995 near Prosperous Bay. Two further ninth abdominal tergites have been recovered since. The first was found under a discarded piece of equipment in the centre of Horse Point Plain in 2013; the second in a small area at the Millennium Forest in 2014 where some remaining surface rock is present. However, this second fragment was found in a concentration of invertebrate remains in the lair of a predatory spider. As all of these remains are fragmentary and the insect itself relatively robust with remains persisting potentially for many decades it has to be assumed that these specimens had been dead for a considerable time. The species is large, charismatic and of iconic status on the island; while there is still a slim possibility that it may still persist in some remote location, the balance of evidence points towards the species being extinct. The last confirmed adult sighting was in May 1967.