Pheromone content of azinphosmethyl-susceptible and -resistant obliquebanded leafrollers (Lepidoptera: Tortricidae) as a function of time of day and female age

Abstract

AbstractThe effect of time of day and age on the amounts and ratios of four pheromone compounds [(Z)-11-tetradecenyl acetate (Z11-14:Ac), (E)-11-tetradecenyl acetate (E11-14:Ac), (Z)-11-tetradecenol (Z11-14:OH), and (Z)-11-tetradecenal (Z11-14:Al)] was compared in azinphosmethyl-susceptible (susceptible) and -resistant (resistant) female obliquebanded leafrollers, Choristoneura rosaceana (Harris). The amounts of all four pheromone compounds varied during the hour before and five hours after the onset of scotophase. The glands of resistant females contained approximately one half the amount of Z11-14:Ac and Z11-14:OH as the glands of susceptible females during the second and third hours of scotophase, and between 50 and 70% as much Z11-14:Al as the glands of susceptible females during the hour before and second to fourth hours of scotophase. The glands of susceptible and resistant females contained similar amounts of E11-14:Ac. The relative amounts of each of the four pheromone compounds were affected by time of day but not by resistance status. There was a negative linear relationship between the amounts of each of the four compounds and female age in both types of females. The amounts of Z11-14:Ac and E11-14:Ac declined at similar rates with age in susceptible and resistant females; the amounts of Z11-14:OH and Z11-14:Al declined more rapidly with age in susceptible than in resistant females. The relative amounts of the four compounds were not affected by female age. Temporal variation in the relative amounts of pheromone in susceptible and resistant C. rosaceana may be associated with similar variation in the emission of pheromone and corresponding temporal variation in the relative attractiveness of the two types of females.