Taxonomy and biology of the genus Isometroides Keyserling (Scorpionida)

Abstract

From an examination of specimens of the scorpion Isometroides Keyserling collected in Western Australia, South Australia, and New South Wales and a study of the literature, it is concluded that two described species must be regarded as one. I. angusticaudus Keyserling is considered a synonym of I. vescus (Karsch). The genus represents a unique adaptive level, especially in its specialized feeding behaviour. It is distributed throughout the semi-arid inland. These facts make it difficult to find a geographically imposed isolation whereby the genus, once established, could have speciated. Field observations on this rare scorpion are presented. It is widespread, occurring in woodland and semi-arid country. In habit it is terrestrial, vagrant, and is specialized for feeding on burrowing spiders.