Periodical and age-related variation in chemical communication system of black cutworm moth, Agrotis ipsilon

Periodical and age-related changes in sex pheromone signaling and response were studied in the black cutworm moth, Agrotis ipsilon. Females began to c all on the first night after eclosion and called mainly during the second h alf of the scotophase. The percentage of females calling increased from 1- to 3-day-old Females and decreased from 3- to 6-day-old females (P < 0.001) . One-day-old females called later in the scotophase than 2- and 3-day-old females (P = 0.016). The quantity of Z7-12:Ac, Z9-14:Ac, and Z11-16:Ac in p heromone gland extracts of 1- to B-day-old females varied with rime of the photoregime, increasing during scotophase and decreasing during photophase (P less than or equal to 0.001). These oscillations were described by using equations containing angular terms with a period of 24 hr. The quantities of Z7-12:Ac and Z9-14:Ac, but not of Z11-16:Ac, varied with female age duri ng the calling period (P < 0.001, P = 0.021, and P = 0.529, respectively). The ratios of Z9-14:Ac and Z11-16:Ac to Z7-12:Ac did not change with age or time during calling period. Male response to female pheromone in a wind tu nnel increased with age and time of the scotophase. The type of response ex hibited by the males (taking flight, oriented flight, and pheromone source contact) was affected by both age and time of the scotophase (P < 0.001).