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 chrysalid& 

 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 M^eeks 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 EEMEDIAL MEASURES AND M ECHANICAL 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 trqubled 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 worst 

 enemy. The inditference 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 

 torce 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 web& 

 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 canbe^ 

 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 



