MEDITERRANEAN FLOUR OR MILL MOTH. 99 
the caterpillars, which have an almost extraordinary power of dis- 
persing themselves wherever there is suitable accommodation, are to 
be found in flour at bakers’, and are constantly transported to and fro 
in sacks of flour, and likewise in the empty sacks which have carried 
infested flour, and which, when sent on without due disinfection, 
transmit the pest constantly more and more throughout the country. 
The principles of prevention lie in the most extreme watchfulness 
against infestation being brought in (as above), and most scrupulous 
cleanliness and care to remove the very first beginnings of moth 
settlement in the mills. When established, fumigation is sometimes 
of service, but the danger of the use of bisulphide of carbon, and the 
risk of injury to the flour which may be stored in the mills in the case 
of use of sulphur fumigation, is very much against extended use of 
such measures. In very bad attack the turning on of hot steam, 
especially where, as in some of the Canadian treatments, arrangements 
could be made for the steam being ‘‘ superheated,’ answers well as a 
means of getting rid of the trouble; but, at the same time, the 
temporary injury to the machinery, such as rusting the shafting, &c., 
the inconvenience of stopping the working of the mill for a time, 
besides the losses from this and expenses of whitewashings and 
cleanings of every accessible locality where the caterpillars can lodge, 
are a serious matter.* 
The moth, /. kithniella (figured at p. 95) is only about one inch in 
expanse of the fore wings, which are of rather a pale grey with darker 
transverse markings ; the hinder wings whitish and semi-transparent, 
with a darker line from the point along the fore edge. 
The moths lay their eggs on flour, or on ‘ branny stuffs,” or on 
sacks holding flour, or the like places, and the eggs have been seen to 
hatch in a few days. The caterpillars, which are about half an inch 
in length (or a little more), when full-grown, are sixteen-footed, slender 
and cylindrical in shape, and vary in colour from pale red in the 
younger to almost white in the older specimens. The head and 
segment behind the head yellowish brown, the latter divided along the 
middle by a faint line, and above the last segment also there is a 
* Details of the attack and preventive measures which have been attempted 
will be found in the observations of mill-owners sent to myself, and also in the 
Bulletin and Report on the Flour Moth issued by the Ontario Board of Agriculture 
consequently on the first appearance of the H. kiihniella in Ontario in 1889, and in 
the Appendix to the Bulletin published at Toronto, October 15th, 1890, of which 
extracts are given in my Twelfth and three succeeding Annual Reports, these three 
containing the Canadian references regarding the operations with which I was 
favoured at the time with much communication. The pamphlet by Mons. J. 
Danysz, of which the title is given at p. 98, contains such a great amount of useful 
information that (if permitted by the author) I believe the publication of a trans- 
lation of it whole or in part would be of great public service in this country. 
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