Published online by Cambridge University Press: 10 July 2009
The effect of a single flood irrigation cycle on the number of adults of Musca vetustissima Wlk. emerging from cattle dung was examined in the field in south-western Australia. Sets of fresh dung pads were exposed to natural oviposition on the day after a flooding and then every three days until the next flooding, 21 days later. The emergence of flies was compared with that from equivalent sets of dung pads in an adjacent unflooded but otherwise similar pasture. The age-stages most susceptible to drowning were post-feeding larvae and pre-emergent puparia. Reduced fly emergence from dung placed in the irrigated pasture one day after the first irrigation was attributed to suppression of oviposition by the wet conditions. Overall, there was a reduction of 57% in the number of flies emerging in the irrigated pasture compared with the unflooded control.