Net Precipitation Within Small Group Infestations Of The Mountain Pine Beetle

This publication supplements Wood & Bright's 1992 catalogue of the world's Scolytidae and Platypodidae (bark beetles), updating the taxonomy of these two families to nearly the end of 1995 and including all known literature references to the end of 1994 (plus references to articles missed in the earlier bibliography). References which provide new information on taxonomy, host plants, or biology of a species are also included. The format of the supplement closely follows that of the 1992 catalogue. Each genus & species is listed with its page number from that catalogue; additional information on figures, distribution, hosts, and references to other subject areas are given. The publication also includes lists of host plants, arranged by scientific name, and the beetles attacking them.

Tree losses resulting from infestation by the mountain pine beetle (Dendroctonus ponderosae Hopkins) were measured in two stands of lodgepole pine (Pinus contorta Dougl.) where the beetle population had previously been epidemic. Measurement data showed that larger diameter trees were infested and killed first. Tree losses ranged from 1 percent of trees 4 inches (d.b.h.) to 87 percent of those 16 inches and greater d.b.h. Numbers of adult beetle emergence holes averaged 1.3 per square foot of bark area in trees 7 inches d.b.h. and 62 in trees 28 inches and greater d.b.h. The observations indicate that large infestations of mountain pine beetle depend on the presence of large diameter trees within a stand of lodgepole pine, thus implying that beetle population growth is food-limited.