(T_eff, log g)-diagram with stars that show no clear periodic variability on timescales typical for δ Sct and γ Dor pulsators (open triangles), stars identified as red giants (open squares), stars that exhibit stellar activity (bullet), and a Cepheid (cross). The cross at the right top corner represents the typical error bars on the values: 290 K for T_eff and 0.3 dex for log g. The solid thick black and light grey lines mark the blue and red edge of the observed instability strips of δ Sct and γ Dor stars, as described by Rodríguez & Breger (2001) and Handler & Shobbrook (2002), respectively. In the on-line version of the paper the open squares, open triangles, bullets, and crosses, are red, blue, black, and black, respectively.