Interesting behaviour of two wolf spiders Hogna spenceri and H. transvaalica in South Africa (Araneae: Araneidae)

Chelicerae flashing, an interesting behaviour observed in the wolf spiders Hogna spenceri (Pocock, 1898) and H. transvaalica (Simon, 1898), is discussed. Both species are African endemics. The general morphology of the species is discussed and photographs of live specimens are provided showing how the chelicerae colour changes. Notes on their lifestyle, distribution and conservation status are provided.