male Pityogenes chalcographus searching for place to bore on Norway spruce
Byers, J.A. 1989a. Chemical ecology of bark beetles.
The purview of chemical ecology and the recent criticisms
of improper application of theory to bark beetle phenomena is
briefly discussed. Seven levels of research in chemical ecology are
presented as well as their relationship to research on bark
beetles. The biology and chemical ecology of several pest bark
beetles from North America and Europe are discussed in regard to
host-tree selection theories of random landing on trees or
attraction to semiochemicals. The diversity and similarities of
pheromone components among species are presented in relation to
their biosynthesis from host-tree precursors and in relation to the
ecological implications of de novo or precursor syntheses.
Individual variation in biosynthesis of, response to, and release
of pheromones is discussed. Olfactory perception of semiochemicals
at both the electrophysiological and behavioral levels is
presented. Orientation to semiochemicals during walking and flying
is discussed with reference to the significance of dose-response
curves for determining a compound's functionality in short- or
long-range communication. The regulation of attack density,
termination of the aggregation, mechanisms of attack spacing, and
recognition of host suitability are presented in the context of an
individual's avoidance of intra- and interspecifc competition.
Finally, a brief summary of topics where our understanding of the
chemical ecology of bark beetles and their associates is poorly
known is presented.