FLOUR MOTH. 
55 
cause a most serious difficulty in working the mills ; in the words of 
one of my first correspondents, they “ get into the spouts and 
machinery, and do no end of mischief, both by destroying the silks and 
stopping the flow of flour, &c., in the spouts by spinning their web and 
hanging there.” In the report of the Canadian mill owners, in whose 
premises the pest was first found at work in Ontario (and to such an 
overwhelming amount that the mill had to stop work), it was men¬ 
tioned the “ mill-walls, ceilings, cracks, crevices, and every machine 
was completely infested with moths, cocoons, and caterpillars, and 
there was no use going on.”* 
In the account given in 1887 by Mr. Sidney Klein of the damage 
caused by this attack in some warehouses in the East-end of London, 
he mentioned that there were over a thousand tons of flour stored in 
close proximity, .... and “the attack spread with great rapidity until 
one entire warehouse was literally smothered with larvae, and several 
hundreds of pounds’ worth of damage was done.”! 
The above short descriptions of the appearance of the caterpillars 
and their methods of injury are merely given just to convey an idea 
of the nature of the infestations to those to whom the subject may be 
new. Details will be found at length in the publications mentioned in 
footnotes to this paper. 
Prevention and Kemedies. —So far as we see at present, all that 
can be done in this way lies in the most extreme cleanliness, in fumi¬ 
gation, which, however, has to be done with much knowledge of 
chemical effects on flour that may be stored near by, and also in 
application of steam. 
What would be the best remedy of all unfortunately appears to be 
impossible to bring to hear. The infestation takes this enormous hold 
because the proper food of the caterpillars is always present. If 
circumstances allowed of change of material ground, for a while, to some 
other kind of grain or seed on which the caterpillars would not feed, 
this infestation might very soon be got rid of; just, in fact, on the 
same principle as Mustard Beetle is got rid of when it has increased 
so as to be overly troublesome in the Mustard-growing districts in the 
East of England, by ceasing to grow the crop for a year or two. If 
the food crop or food material is removed, the feeder is necessarily got 
rid of, or much lessened in numbers. 
Application of Hot Steam. — As, however, the above preventive 
measure could not be used, I suggested (from previous experience of 
* ‘ Report on the Flour Moth.’ Issued by the Ontario Department of Agriculture, 
October, 1889. 
f ‘ Transactions of the Entomological Society,’ pt. iv. December, 1887, p. lii, 
