INSECT CONTROL IN FLOUR MILLS. 7 



or germ stocks. During* the cooler months the pest is often found 

 in and about the dust collectors, especially if these are warm or are 

 taking heat from the rollers. It should be taken for granted that 

 returned or secondhand sacks are infested and must be treated before 

 being taken into the mill proper. The moth is too widely distributed 

 to-day to justify a miller in taking chances with these sacks. 



METHODS OF CONTROL. 



The control measures for the Mediterranean flour moth, and, in- 

 cidentally, for other mill pests, may be divided into three classes: 

 Preventive, including attention to cleanliness; natural control, deal- 

 ing with nature's attempt at control by parasites; and artificial 

 control, including destruction of pests by fumigation, heat, and 



cold. 



PREVENTIVE MEASURES. 



The need for cleanliness can not be overemphasized. Insects prefer 

 to lay eggs upon and develop in flour and cereals lying in undisturbed 

 darkened situations. Insects are most abundant in such places. The 

 frequent cleaning out and destruction of such material nips in the bud 

 what may become an infestation causing a loss many times greater 

 than the cost of cleaning. Experienced millers know this. 



FREQUENT CLEANING. 



A large proportion of insect infestation in flour mills is due di- 

 rectly to lack of cleanliness. This does not mean that the product 

 coming from such mills is unclean, but that flour is allowed to ac- 

 cumulate for long periods in various places throughout the machinery 

 and buildings to serve as a rich breeding ground for pests, which 

 multiply rapidly and spread to all parts of the mill. It has already 

 been stated that under ordinary flour-mill conditions during the 

 warmer months, the Mediterranean flour moth requires about nine 

 weeks for each generation. Certain other mill pests require from 5 

 to 7 weeks to complete their life cycle. It is, therefore, evident that 

 if mills are given a thorough cleaning about every five weeks through- 

 out the summer months, much good will be accomplished in reducing 

 pests, for in destrojdng the stocks removed from undisturbed or dead 

 spaces, many insects are captured and destroyed also. Labor to brush 

 out and remove accumulation of stocks from elevator boots and flour 

 conveyors, and to destroy them by burning is labor well spent. Going 

 over elevator legs with a spout maul, or the use of elevator and belt 

 brushes (fig. 4), will dislodge much infested material and aid 

 greatly in remdving accumulations 



