DUNE SPIDERS OF THE NEGEV DESERT WITH NOTES ON CERBALUS PSAMMODES (HETEROPODIDAE)

ABSTRACT

The community of spiders that burrow into the sand dunes of the northwestern Negev Desert was examined. Nine species were found, of which only two occurred on the unconsolidated, active dunes. The remainder occurred on the fixed bases of the dunes and the interdune depressions that were mostly covered by a biological crust. All spiders that dug their own burrows constructed vertical tunnels, which they excavated by carrying silk-sand bundles. Observations of Cerbalus psammodes (Heteropodidae) revealed it to be the Negev counterpart of the dominant heteropodid spiders occurring in the Namib dunes. Parallel characteristics include its large size, the method of burrow stabilization (but not of excavation), nocturnal activity, 1–2 m home ranges, predation on tenebrionid beetles, sexual size dimorphism, and maternal care.