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-GROUP 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 
Agriculture of the West Indies that are injurious to cattle in St. Lucia 
proved to be the well known “ Screw Worm ” Fly. The scientific 
name of the fly is Compsomyia macellaria, of Fabricius. 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. Where 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 ravages, especially in the nose and ear ( vide 
“ Psyche ” iv., pp. 27-30, 1883, and page 131). Amongst the 
many excellent accounts 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. 
