A survey to determine relative incidence of blowfly species in strikes and resistance levels in field strains of Lucilia cuprina, the most important sheep blowfly, from throughout the sheep areas of Queensland was conducted in 1977. L.cuprina was by far the most common species, being present in 90% of strikes. Chrysomya rufifacies (27%) and Calliphora augur (10%) were the next most common, the latter occurring only in winter strikes in southern Queensland.
All field strains tested were resistant to organophosphorus compounds but not all showed resistance to butacarb. Resistance factors to diazinon varied from 7.3 to 18.9, the mean being 10.9
Eggs of L.cuprina, Calliphora stygia, C.augur and Austratophyra rostrata were described using scanning electron microscopy. Keys and illustrations to separate the first and second instar larvae of L.cuprina, C.stygia, C.augur, Ch.rufifacies, Ch.varipes, Ch.saffranea, Ch.nigripes, A.rostrata and those of the family Sarcophagidae are given and compared with rates of development in the field.
The use of this data for forensic purposes, to estimate the length of time elapsed since death, is discussed.