October, '15] BISHOPP-LAAKE : WOOL MAGGOTS OF SHEEP 



467 



ular, every shepherd is farailiar with this type of injury, and the 

 watching of the flocks for infested animals and the destruction of the 

 maggots are a part of their routine work. The common green-bottle 

 fly, Lucilia sericata, is responsible for the trouble in Great Britain, and 

 also in parts of continental Europe. Only those animals which have 

 the wool considerably soiled with blood, faeces or urine are attacked. 

 This species of fly is abundant in the United States, and, in fact, is 

 almost world-wide in distribution. 



The wool maggot assumes much greater importance in Australia 

 than in any other part of the world. This, of course, is due to a con- 

 siderable extent to the vastness of the sheep industry in that country. 

 Professor W. W. Froggatt^ states that during a single year the loss 

 due to wool maggots in Australia was conservatively estimated at a 

 million pounds. In that country eight species of flies are found to 

 blow sheep, namely, Calliphora villosa, C. oceanice, C. rufifaces, C. vari- 

 pes, Lucilia sericata, L. ccesar, Ophyra nigra, and Sarcophaga aurifrons. 

 Professor Froggatt states that until about ten years ago only wounds 

 of sheep were blown, but recently the flies appeared to have acquired 

 the habit of attacking sheep of all classes upon the slightest provoca- 

 tion. In Hawaii another species of Calliphora (C. dux) has been 

 reported by Van Dine^ as causing serious injury to sheep by blowing 

 the soiled wool. 



Type of Injury and Species Concerned 



In various parts of the United States the infestation of soiled wool 

 on sheep is not uncommon, and in certain sections this is a problem of 

 no little importance. Through the Central States the infestations 

 usually occur in mid-summer and are confined largely to lambs or 

 heavy wooled ewes which have the wool about the rumps soiled from 

 diarrhea, or from being kept in dirty paddocks. A similar condition 

 prevails in the Northwestern States, though infestations are infrequent 

 as far as has been learned. The species of the fly or flies concerned 

 in this injury has not been positively determined, although it is be- 

 lieved that the green-bottle flies, Lucilia sericata and L. ccesar, are 

 responsible, at least in part. 



In southwestern Texas, where the sheep industry is one of large 

 extent, a somewhat different condition prevails. The most acute 

 trouble occurs early in the spring, usually during April. The injury 

 is of two types. First, the infestation of the wool about the rumps 



^ Froggatt, W. W., 1914. Sheep maggot flies in Australia. Bulletin of Entomo- 

 logical Research, Vol. 5, Pt. 1, pp. 37-39, April. 



2 Van Dine, D. L. and Norgaard, A. A, 1908. Abstract of a preliminary report on 

 insects affecting live stock in Hawaii. Proc. Hawaiian Live Stock Breeders Assoc., 

 pp. 19-70. 



