ENTOMOLOGY

MYIASIS-TYPES OF INJURY, LIFE HISTORY, HABITS 181plague of myiasis among sheep. The center of the region where thi~scourge occurs is in New South Wales, where work for the commonwealth -government has been carried on by Professor W. W. Froggatt for severalyears. Only a brief mention of the species concerned and the characterof attack can be given.The loss is brought about through the blowing of the soiled wool,particularly around the vents of the ewes. The infestation, if notpromptly treated, spreads forward in the wool, resulting in a large loss inthe clip and often the larvre gRin entrance to the bodi~s of sheep andcause their death. Even though penetration does not occur, the skin isacutely inflamed and gives rise to fever, loss of appetite, and sometimesdeath. Froggatt states that he has bred 1,050 flies from the maggots inone pound of wool.Froggatt holds that the blowing of wool is largely Rn acquired habiton the part of Australian flies, as practically no cases of this kind werenoted up to 1908 or 1904. He attributes the acquisition of this habit tothe extended drought which destroyed large numbers of animals of allkinds and resulted. in the production of myriads of flies. He thinks thatduring this period several species of flies acquired the habit of depositingin "smelly" wool. He also considers the more extensive breeding of heavywooled sheep to be a contributory factor. It is certain that injury fromblow-flies has developed from an' almost unnoticed trouble to a problemof first magnitude within the space of a few years. During the firstfew years of the acute trouble the small yellow house fly, Anastellorhinaaugur Linnreus, and the golden hair blow-fly, Neopollenia stygia(Fabricius) Townsend (Pollenia villoso, Robineau-Desvoid'y) appearedto be the principal culprits. In 1918, when the work was taken up moreextensively it was found that the "green and blue" sheep maggot fly,Chrysomya rufifacies Macquart (Pycnosoma), was assuming first importancein connt!ction with the infestation of sheep. The difference inapparent injuriousness is probably governed largely by the seasonalconditions as in the case of species in our own country, C. rufifacics apparwtlybeing concerned largely with cases of myiasis in summer and A.augur during the cool weather. The life histories of these flies do notdiffer materially from tllat of the screw-worm fly, the life cycle beingcompleted in about two weeks under favorable conditions. Other specieswhich have been bred from wool in Australia are Microcalliphora varipes(l\!acquart) Townsend, the Anthomyid, Ophyra nigra Wiedemann,Sarcophaga aurifrons Macquart, and the cosmopolitan Lucilia sericataand L. CfEso,r, and possibly L. tasmanien8i8.