"Detection of insect fragments in wheat flour by near-infrared spectroscopy"
Published by the Grain Marketing and Production Research Center, USDA, ARS, 1515 College Avenue, Manhattan, KS 66502, USA
Abstract: Insect fragments in commercial wheat flour are a major concern to the milling industry because consumers expect high quality and wholesome products at the retail level. Thus, the US Food and Drug Administration (FDA) has established a defect action level of 75 insect fragments per 50 g of flour. Millers routinely test their wheat flour to comply with this federal requirement and to deliver sound flour to their consumers. The current standard flotation method for detecting fragments in flour is expensive and labor intensive...." The article goes on to describe current and emerging technology to address this issue with flour. Published in 2002.
I read it as "just another reason to buy wheat berries and other grains WHOLE and sprouting/dehydrating them before grinding them into flour yourself at home".
Insect fragments are a non-issue when you start with berries and sprout them because you can rinse them till your hearts desire before you soak! Home mills are conveneint and relatively affordable. If you bake enough the mill will pay for itself eventually. But the rewards are more than monetary - the satisfaction of milling your own flour is priceless, really. And don't forget how nutritious and digestable the grains are after they have sprouted.