Fig. 1. A group of four large pines in rocky terrain colonized by Ips acuminatus and (one of the trees) Phaenops cyanea second summer after their death (A). Section of upper trunk entirely covered by I. acuminatus galleries (B). In trees where the bark has fallen off, it is easy to ascertain the presence of I. acuminatus based on its characteristic galleries using binoculars or a digital camera with a sufficient zoom (here about 15x).

Fig. 2. Diameter distribution of pines (n = 96) colonized by Ips acuminatus.

Fig. 3. Frequency distribution of tree group sizes (no. of adjacent dead trees forming a group) colonized by Ips acuminatus.