What indicates that flour is infested with Indian Meal Moths?

The indication that flour is infested with Indian Meal Moths is most notably marked by the presence of a large amount of webbing in the flour. This webbing is produced by the larvae as they feed and develop within the flour. It can often be seen as fine silk threads that are intertwined with the flour, making it a clear sign of infestation.

In contrast, while the presence of larvae and adult moths can indicate an infestation, they are not as definitive as the webbing itself. Adult moths can sometimes be found outside the stored product, and visible larvae might not always be present depending on the lifecycle stage of the infestation. Finally, pure and clean flour, devoid of any signs of contamination or infestation, would indicate a lack of Indian Meal Moths. Thus, webbing serves as a more reliable and visible sign that an infestation is actively occurring within the flour.