Byers, J.A. 1981b. Effect of mating on terminating aggregation
during host colonization in the bark beetle, Ips paraconfusus. Journal of Chemical Ecology 7:1135-1147.
Female Ips paraconfusus showing rainbow colored stridulatory organ on top of head
Abstract--
Attraction of male I. paraconfusus to male-infested ponderosa pine
logs was inhibited by volatiles from logs infested with mated males
and females over an 8-day period in the field. The response of
females during this time was not significantly inhibited by these
volatiles. Synthesis of the male-specific pheromones, ipsenol and
ipsdienol, appeared negligible after 8 days in males allowed to mate
with 3 females in these logs while males alone contained levels of
these pheromones at about half their maximum rate. The decline in
pheromone production in mated males appears to result, in part, from
a reduction in the activity of the biosynthetic system that converts
the host monoterpene, myrcene, to ipsenol and ipsdienol. Mating and
feeding have no effect on the biosynthetic system that converts the
host monoterpene, (-)-alpha-pinene, to the pheromone, cis-verbenol
in either males or females. The reduced production and release of
pheromones by males after mating may play a major function in the
process of terminating the aggregation phase of host colonization.
Chemical Ecology