Effects of bait age on the number, sex, and age composition of Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae) in Western Australian blowfly traps

Abstract

Daily catches of the Australian sheep blowfly, Lucilia cuprina, in Western Australian blowfly traps were not significantly affected by exposing the baits in traps for up to 3 days in the field before trapping. Exposure of the baits for longer periods significantly increased the daily catch totals of both sexes. Baits with a mean exposure time before trapping of 7 days (old baits) returned significantly higher catches than baits with a zero exposure time (fresh baits): 5-fold and 3-fold increases, respectively, for males and females. Exposure of baits for only 1 day was sufficient to produce significant changes in the reproductive age composition of female catches; proportions of newly emerged females increased and proportions of gravid females decreased. Coefficients of variation for old bait/new bait catch ratios were small, 16.4% for males and 12.3% for females, which confirmed that both baits exhibited consistent levels of attractiveness on different trapping dates. Procedures are suggested for estimating population densities of L. cuprina based on trap catches using fresh and old baits.