Notes on the Œstridæ, 
by Profr. GEORGE H. CARPENTER, Royal College of Science 
(Dublin). 
I. The Ox Warble-Flies. 
Hypoderma bovis (DE GEER) and H. lineata (VILL). 
The life-history of the common Warble-Flies of the Ox presents 
several problems of great interest to the naturalist and of consider- 
able practical importance to the farmer and the cattle-owner. It 
may be advisable, therefore, to place on record, in the proceedings 
of the first International Congress of Entomology, a summary of 
some experiments and observations which have been made on 
the subject, over a period of six years, under the auspices of the 
Irish Department of Agriculture (1). 
One object of these experiments was to test the value of the 
washes and smears often recommended for application to Cattle 
during summer in order to prevent the female Fly from laying her 
eggs. During three successive summers a number of Animals, 
Calves, Yearlings and Milch Cows, were dressed in various ways, 
some on the back, some on the legs and some all over, once a week, 
or daily through the season, while a number of similar Animals 
(1) Three reports of these experiments have been published in the « Journal 
of the Department of Agriculture and Technical Instruction for Ireland ». The 
first (by G. H. CARPENTER and J. W. STEEN) in vol. VIII, n° 2, 1908; the 
second (by G. H. CARPENTER and W. F. PRENDERGAST) in vol. IX, n° 3, 1909, 
and the third (by G. H. CARPENTER and T. H. CORSON) in vol. X, n° 4, 1910. 
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