Flour Mill field trip and Stored Product Pests

On November 18th we were able to go on a field trip to one of two flour mills located on the Kansas State University Campus where we able to get a better understanding of the efforts they must take to keep pests at a minimum within a mill. When managing pests in the field prior to harvest there are many different aspects to consider. For instance how can we control a problem pest without having a secondary pest outbreak? In the field we have natural enemies and cultural control methods that help to keep some pests in check. Also we can use some fairly harsh chemicals early in the year that will not be persistent in the grain, whereas we need to be very cautious about what chemicals are applied to stored grains especially if they are going to end up in a food supply.





Some major challenges that these mills present are the amount of small unreachable areas that pests are able to hide and build populations within these buildings. The picture above shows just a small area of the mill we were in, but even in the photo you can see the amount of machinery and equipment that is present within. Inside these machines are cracks and crevices that insects can crawl into and around, while feeding on the fine dust that is deposited from the milling process. Older mills, some with wooden floors even, have a greater deal of these small hiding places that are ideal for pests to live within. So it can be somewhat more challenging to keep them free of pests.






If i was to design my own mill, i think it would be full of bugs! The KSU mill is designed to be easy to clean and try to minimize the areas that allow pest populations to develop. First off i really liked some of their ideas, like to keep objects off the floor that would require sweeping around and provide areas for milling dust to gather. The floors were sloped up to machines to help prevent dirt from gathering at the bases. Trash cans were held off the floor. All of these are ideas that i never would have come up with, but yet they really help to keep the mill clean.


Yes, phosphine can be used within a flour mill as it leaves no harmful residue on the product. But it does promote the rusting of metals within the mill. Also pests can build up resistance to it so if it is the only method used it may loose effectiveness.


When unloading my first load of corn, I would make sure to seal up all the openings in the bin to make it difficult for pests to enter. Also i would have applied a pesticide barrier prior to filling any bin with grain to kill insects that are present and to deter others from entering. Once the bin has been filled with grain, using a bin fan to move air within the bin to control temperature would be another approach. If the temperature inside the bin is less than favorable for insects thay are less likely to be entering.