“One of the most remarkable species of insects that I obtained during a recent (December, 1915, and January, 1916) visit to Lord Howe Island is a large wingless phasma, Karabidion (formerly Eurycantha) australe, Montr. It appears to have been taken by almost every natural history visitor to the island, and, in fact, once their hiding-places are known, specimens may be taken in practically unlimited numbers. During the day they remain concealed in hollows in upright or slightly sloping stems of living trees, but their presence may be detected by examining the ground at the foot of the trees, where heaps of their excrement, sometimes amounting to bushels, may be found. The hollows are seldom less than eighteen inches in length, and are sometimes much longer; suitable ones are probably used for years. On examining the heaps of droppings, frequently both fresh and newly-hatched eggs may be found, the females apparently simply extruding their eggs as soon as these are ready” (Lea, 1916).
Worldwide, there are about 0.75–1 million known species of insect (class Insecta) (IUCN 1983), of which 72 species are currently regarded as extinct (IUCN 2000). The majority of these extinct insects came from island communities, particularly those that exhibited a high degree of endemism. Globally the principal causes of insect extinctions include deforestation, changes to aquatic environments, atmospheric pollution, loss of hosts, the introduction of exotic plants and animals, over-collecting and the use of pesticides (IUCN 1983). The largest of the extinct insects is the Lord Howe Island Stick-Insect (D. australis (Montrouzier)).
Conservation of this species should have a high priority. There are a number of issues that will follow from this study, namely the establishment of the breeding population on LHI- dependent on knowing their biology and behaviour, the threat of the weed, morning glory Ipomoea cairica, the removal of the rat population, and the most difficult issue to confront will come from us (humans) perception of insects as just bugs or pests. This species is not a pest and during the course of this project one of the major outcomes will be to high light the species vulnerability and the importance of insect (invertebrate) conservation.
The above photograph was taken by Nicholas Carlile, and the full article of the rediscovery can be found in Biodiversity and Conservation 12:1391 -1403, 2003. David Priddel et al.