Abstract
Pitfall traps were used to study the distribution and seasonality of darkling beetles (Tenebrionidae) at four sites in the Huraymala wadi of the Central Region of Saudi Arabia, from February 1988 to February 1989. Two of the four were cultivated and the others were uncultivated. In all 2386 tenebrionid specimens were trapped, representing 26 species. The most abundant were Mesostena puncticollis Solier, Zophosis sp, Adesmia cancellata (Klug), Scleron orientale Fab., Akis elevata Solier and Trachyderma philistina Reiche. The abundance and diversity of the beetles were significantly greater in uncultivated sites than that in the cultivated sites. M. puncticollis, A. cancellata and T. philistina were found in all sites. Zophosis sp. and A. elevata were found only in uncultivated sites. S. orientale, Gonocephalum rusticum (Olivier) and G. soricinum were found almost entirely in the cultivated sites. Numbers of tenebrionids trapped in winter and mid summer were low, they reached a peak in June. The rainfall over the two months preceding collection had an effect of 69–79% on beetle abundance.