Male Scent Emitted by Armyworms, Pseudaletia unipuncta and P. separata (Lepidoptera : Noctuidae)

Male scent compounds were detected in scent brushes on the 1st and 2nd sternite of Pseudaletia unipuncta and P. separata No chemicals were detected from posterior abdominal brushes and from hairs on genitalia of P. separata. Changes in male scent quantity with age in P. unipuncta were determined. The male isolated from the female had an average of 5.8 μg/brush benzaldehyde at day 1 after emergence. Benzaldehyde increased significantly until day 5 and attained its peak of an average of 11.2 μg/brush. It decreased significantly from day 5 to day 7, and also had a slight decrease until day 15. On the other hand, an average of 14.2μg/brush benzyl alcohol was detected at day 1. It decreased significantly with age and went down to almost zero on and after day 5. The males stimulated by the female had lower amount of benzaldehyde and had higher amount of benzyl alcohol than the virgin males of P. unipuncta. When air extraction of male scent was made in P. separata, onle benzaldehyde was detected during male courtship.