43 
they had left the larva and were forming cocoons on the side of 
the tube. The cocoons were completed by 8 o’clock, September 
20, and were whitish in color. The fully developed chrysalids 
could be plainly seen by the 23d, in which condition they re¬ 
mained until October 7, when the adult parasites emerged. From 
this one observation it appears that the grubs reach maturity in 
one or two days; that one' day is required for the construction of 
the cocoon; and that a little over two weeks is passed in the 
pupa stage, making about three weeks for the complete life cycle 
of the parasite. It will be remembered that about nine weeks 
are required for the complete evolution of the flour moth, so that 
there would be three generations of the parasite during a like 
period. 
PREVENTIVE AND REMEDIAL MEASURES AND MECHANICAL DEVICES. 
• 
It is now a well-known fact that this moth is carried from mill 
to mill in the greater number of cases through carelessness. 
Millers who have never been troubled with insect pests think there 
is nothing to fear, and carelessly permit all sorts of material, such 
as empty bags, barrels, boxes, and second-hand machinery, to enter 
their premises without even suspecting the presence of their w r orst 
enemy. The indifference displayed by most millers who have been 
fortunate enough to escape the ravages of insect pests in their 
mills, is truly lamentable. All preventive measures are ignored, 
the mills are often dirty through neglect, and unconcern prevails. 
These very people, sooner or later, will suffer severe mental anxiety 
and heavy financial loss for their negligence. Other firms neglect 
their mills simply because they are new, thinking they have noth¬ 
ing to fear from outside foes. Some of the worst flour-moth out¬ 
breaks recorded in this country have occurred in newly con¬ 
structed mills. One of the newest mills in California was obliged 
to shut down before it had run six months, and employed a 
force of men to take down all spouts and elevators and clean out 
the accumulations from them. The Canadian outbreak at Val- 
leyfield, Quebec, is another instance. The mill was constructed 
about a 3 ear ago, and has been obliged to shut down several 
times during the past season in order to clean out the webs 
from spouts and elevators. When a mill is clean and new it 
would certainly be good policy on the part of the owners to keep 
it fresh and clean. In this day of common insect pests, a sweeper 
or duster is indispensable to the successful operation of a mill. 
He should be thoroughly acquainted with all insects injurious to 
mills, mill products, and stored grain, and competent to apply 
such measures as may be requisite for their arrest and destruc¬ 
tion. He should be responsible for the inspection of all incom¬ 
ing material, of whatever sort, where there is the slightest ques¬ 
tion as to its freedom from insect pests. 
Where the flour moth has established itself in a mill, it can be 
kept in subjection only by the most persistent and energetic fight¬ 
ing. The standard remedies are steam, sulphur, and bisulphide 
of carbon, all of which are soon to be considered in detail. I shall 
