52 
twenty, sometimes even a hundred, or two, three or four hundred, 
of these strong maggots growing up to an inch in length and 
feeding in the sore, which they keep up from January or February 
until they are full-grown. 
Amongst these may be specially mentioned losses to fatting 
beasts; in the words of Mr. R. Stratton, a most careful observer, 
written during hot weather in August, 1884: —“Cattle are suffering 
very much at this time from the fly. Fancy a fat beast having to 
run perhaps ten miles a day in this heat ! Many lose £1 worth 
of beef in a week from this cause.”—R. Stratton, The Duffryn, 
Newport, Mon. 
The following note, from personal observations by Mr. D. Byrd, 
Spurstow Hall, Tarporley, Cheshire, gives approximate estimates of 
loss of value on growth of feeding cattle from disturbance, and on 
weight of cheese and percentage of milk calculably lessened by the 
same cause:— 
“We all know, to our cost, how greatly these tormenting flies 
irritate and madden the cattle, causing them to gallop or run as if 
for their lives to get away from the buzz and presence of their 
tormentors. Feeding cattle cannot grow in flesh without quiet and 
rest, and milking cows must suffer to a greater extent than we are 
aware of. To use a common remark, they soon ‘bate,’ i.e. give less 
milk. To drive a cow fast, or cause her to be excited, reduces the 
quantity and quality of the milk. Without perfect quiet and rest 
they cannot do their best for us. 
“ This leads me to the important point—What is our loss in the 
cheese-tub caused by the Warble and Gad Fly? I have tried to 
estimate the loss during the four or five summer months, or even 
the eight months, that a cow is supposed to be in profit. There 
are certain times of unrest when the cow will give about one-half 
of her usual flow of milk. These tormenting flies, and the con¬ 
tinued presence of the prickly-coated warble-maggot, must keep up 
a perpetual uneasiness, and retard the growth of our feeding cattle 
to our loss, it may be, of £2 per head. In the dairy cows the loss 
will be greater. The daily loss of milk may make a difference of 
1 cwt. or \ cwt. of cheese per cow per annum. Half a hundred¬ 
weight, or 12^ per cent., of milk less in a dairy making 4 cwt. at 
70s., comes to 85s. ; but 12| per cent, is too low an estimate : it 
may in some cases be put at £3 per head, and in a dairy of 
100 cows would show a loss of £300.” 
Loss on milk .—The only precise calculation I know of on the 
subiect is thus referred to by the late Prof. Riley, Entomologist of 
