Byers, J.A. 1981a. Pheromone biosynthesis in the bark
beetle, Ips paraconfusus, during feeding or exposure
to vapours of host plant precursors. Insect Biochemistry
11:563-569.
Sampling headspace air from inside male Ips paraconfusus nuptial chamber
in ponderosa pine, Pinus ponderosa
Abstract--
The quantities of trans-verbenol, myrtenol and the pheromone,
cis-verbenol, in the hindguts of males and females increased in linear
proportion following exposure to increasing concentrations of vapor
of the host plant precursor, (-)-alpha-pinene. Males produced
significantly more of these compounds than females. Differences
between males and females in the ratios of compound production were
indicated. The concentrations of myrcene, alpha-pinene and other
monoterpenes volatilized in male nuptial chambers in ponderosa pine
(Pinus ponderosa) were quantitifed as well as the amounts in phloem.
Males do not appear to ingest sufficient phloem to obtain enough of
the host plant precursor, myrcene, to account for production of the
pheromones, ipsenol and ipsdienol, but they may consume additional
amounts of myrcene in oleoresin/xylem. Comparisons of ipsenol,
ipsdienol and cis-verbenol production in males when feeding or
exposed to precursor vapors at various concentrations indicate that
under natural conditions, myrcene used in pheromone biosynthesis
primarily enters the beetle via the digestive tract.
Chemical Ecology
