Published online by Cambridge University Press: 10 July 2009
Ultraviolet-light and fermentation trap catches of adults of Mythimna convecta (Walker) in Victoria, Australia, could be related to the times of various stages of larval development in oat crops by means of a day-degree accumulation model. Mated females were more attracted to fermentation than ultraviolet-light traps, and predicted oviposition times closely coincided with fermentation trap catches. The phenological model successfully mimicked the observed larval instar development in the field. Peak moth flights occurred within three periods. The first peak period (October to mid-November) usually contained mated moths which generated larval populations in maturing oat crops; in 1983, these moths probably occurred in late August. The second (mid-November to December) contained unmated females; in 1983–84, moth flights during this period could be related to the emergence of moths from crops 70–130 km north of the trap site. The third peak period (January to February) also comprised unmated moths which had usually emerged locally and were probably emigrating.