110 
WARBLE FLY. 
while those from Calcutta, Madras, and Bombay are depreciated 
perhaps to the extent of 50 per cent, on 10 per cent, of the skins. 
“ ‘ From Cape Colonies the damage is comparatively slight, and still 
less in those hides and skins from Australia and South America.’”— 
Communicated by Sec. of Colonial Co., Leadenhall Street,London. 
The following note, from personal observations by Mr. D. Byrd, 
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 ’—give less milk. To drive a 
cow fast, or cause her to he 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 one important point. What is our loss in 
the clieese-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 continued 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 he, 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 f cwt. of cheese per 
cow per annum. Half a hundredweight, or 12} per cent., of milk less 
in a dairy making 4 cwt. at 70s., comes to 35s.; 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.”*— D. Byrd, 
Spurstow Hall, Tarporley, Cheshire. 
* The above note also formed part of a paper communicated by Mr. Byrd to the 
‘ Chester Chronicle ’ of Feb. 7th, 1884. Mr. Byrd’s mention of “the Warble and 
Gad Fly” is very important, as these two very different attacks are often confused. 
The Gad Fly, Tabanus bovinus, is much larger than the Warble Fly, and injures 
the animals by driving its sucking apparatus into them very painfully and drawing 
away the blood, and also, like the Warble Fly, by terrifying them into the wild 
gallops we know so well. From some of the subsequent observations given on p. 113 
it appears that the applications noted as useful to keep oh one sort of Fly are 
equally useful to keep off the other ; and this point of the cattle so dressed being 
able to feed in peace whilst the others were being hurried in all directions is well 
worth consideration. 
