132 First Report on Economic Zoology. 



GROUP E. 



Animals which concern Man as causing bodily injury or 

 disease, both possibly of a deadly character, to (A) his 

 stock of Domesticated Animals, or (B) to his Vegetable 

 Plantations, or (C) to Wild Animals in the preservation 

 of which he is interested, or (D) Plants in the preservation 

 of which he is interested. 



SUB-GEOUP A. ANIMALS WHICH CONCERN MAN BY 

 CAUSING BODILY INJURY OR DISEASE TO HIS 

 STOCK OF DOMESTICATED ANIMALS. 



The Screw Worm in Cattle in St. Lucia. 



Two diptera sent by the Director of the Imperial Department of 

 Agiiculture of the West Indies that are injurious to cattle in St. Lucia 

 proved to be the well known " Screw Worm " Ely. The scientific 

 name of the fly is Compsomyia macellaria, of Fabriciiis. There is 

 any amount of literature on this pest, its life-history being well 

 known. 



The fly is common from the Argentine to Canada. It especially 

 attacks the natural openings of animals, notably the " sheaths " of 

 horses and the navel of newly -born animals ; but the fly will lay its 

 egg upon any abraded surface of the skin. Wliere ticks, etc., have 

 been killed on an animal is a favourite place for the fly to deposit 

 her eggs, the fly being attracted by the blood. Abrasions from 

 contact with barbed wire form favourite localities. Human beings 

 are also subject to its rarages, especially in the nose and ear {vide 

 "Psyche" iv., pp. 27-30, 1883, and page 131). Amongst the 

 many excellent account| issued by American stations is the 

 following : — \ 



Bulletin of the Agricultural Station of Louisiana, No. 2, second 

 series. "The Texas Screw Worm," by Prof. H. A. Morgan, 1890. 



All animals seem to be attacked by it. 



