Light trap data is used to illustrate a successful history of forecasting December outbreaks of Persectania ewingii (Westwood), southern army- worm caterpillars in Tasmanian cereal crops and pasture between 1954 and 2006. Spring catches varied by 2-3 orders of magnitude and large catches always preceded outbreaks. Thresholds indi- cating likely outbreaks were determined empirically and varied from trap to trap, being a spring catch of 50 moths for traps at Elliott and Ouse, but only eight for the trap at Cressy. Unusual early or late season outbreaks are also discussed. Comparisons among several traps in a network operated by the state agricultural agency are given and indi- cate considerable correlation. Outbreak years since 1912 are listed along with notes on early records of the pest. The identity of the species likely to have caused outbreaks is clarified as southern armyworm and common armyworm by examining light trap data and historic pest records to exclude several other Hadeninae or Spodoptera species.
Cite this article as:
Hill, L. (2013). A history of forecasting outbreaks of the southern armyworm, Persectania ewingii (Lepidoptera: Noctuidae) in Tasmania. Plant Protection Quarterly 28(1), 15-21.