FIGURE 1. The water-capturing surface of the fused overwings (elytra) of the desert beetle Stenocara sp.

a, Adult female, dorsal view; peaks and troughs are evident on the surface of the elytra. b, A 'bump' on the elytra, stained with Red O for 15 min and then with 60% isopropanol for 10 min, a procedure that tests for waxes. Depressed areas of the otherwise black elytra are stained positively (waxy, coloured), whereas the peaks of the bumps remain unstained (wax-free; black). c, Scanning electron micrograph of the textured surface of the depressed areas. Scale bars, a, 10 mm; b, 0.2 mm; c, 10 m.