MONITORING POPULATION LEVELS OF EIGHT SPECIES OF NOCTUIDS WITH SEX-ATTRACTANT TRAPS IN SOUTHERN ALBERTA, 1978–1983: SPECIFICITY OF ATTRACTANTS AND EFFECT OF TARGET SPECIES ABUNDANCE

Abstract

AbstractThe abundances of eight species of cutworm and armyworm moths were monitored with sex-attractant traps at 81 locations in a 13 000-km2 area of southern Alberta from 1978 to 1983. The life history and economic status of each species is summarized and the monitoring methodology is described. The attractants for redbacked cutworm (Euxoa ochrogaster), darksided cutworm (Euxoa messoria), pale western cutworm (Agrotis orthogonia), and army cutworm (Euxoa auxiliaris) were highly specific and > 99% of the moths caught were of the target species. Specificity of the attractants for clover cutworm (Discestra trifolii) and Leucania commoides was also high, averaging 98.3 and 96.6%, respectively, over 6 years. The attractants for variegated cutworm (Peridroma soucia) and bertha armyworm (Mamestra configurata) were less specific but the proportion of target species exceeded 80% in those years when either species was relatively abundant. For those species that were monitored over a wide range of population levels, the apparent specificity of the attractant varied directly with the number of target species moths caught. The use of efficient attractants in combination with high-capacity nonsaturating traps is clearly of advantage in enhancing specificity.