| Attraction to bark/phloem/xylem disks of Pinus radiata D. Don was demonstrated, with I. p. maritimus Lanier (Coleoptera: Scolytidae) females exhibiting a higher attraction than males. Attraction of males and females to male infested disks and to captured male volatiles increased with increasing dosage. Attraction of males and females to female infested disks and to captured female volatiles was demonstrated. Increasing numbers of females in male galleries reduced the attractiveness of infested disks to either sex. Increasing numbers of females, tunneling separately from males in the same disk, reduced attraction of males. Increasing concentrations of male and female volatiles released in a one-to-one ratio decreased attraction for both sexes combined. Attraction of both sexes to volatiles derived from males and females tunneling together, increased with increasing dose. Hence, both sexes produce an aggregation pheromone, and interaction between the sexes often reduces male and female attraction. |
