Coexistence of Ammoxenus (Gnaphosidae) spider species on and between termitaria of Microhodotermes viator (Hodotermitidae) at a Karoo site

Abstract

Previous studies of some species of Ammoxenus spiders demonstrated them to be monophagous predators of certain termites. Upon observing Ammoxenus spiders preying on the hodotermitid, Microhodotermes viator, we examined the distribution of spiders on or off termitaria (termed heuweltjies) at the Tierberg-LTER study site in the Karoo using pitfall traps deployed monthly over two years. Four species of Ammoxenus were found, but only one, Ammoxenus pentheri, has been described, the other three being new to science. Their coexistence prompts questions concerning niche partitioning among several specialist predators. Our initial study revealed that Ammoxenus and other ground spiders were more abundant on heuweltjies than in the matrix between heuweltjies. The different Ammoxenus species appeared to be disparately associated or disassociated with heuweltjies and had different phenologies. This case of niche partitioning among specialist predators warrants further study.