Infestations in the Real World: Quantifying Milling Losses

Hard red winter wheat is poised to lead U.S. wheat production this season, but its quality and profitability can be quickly compromised if insect infestations in storage go unchecked.

Insect activity in stored wheat impacts grain condition, flour yield, product quality, and raw material efficiency. These are key findings from a recent controlled study shared by our Technical Services expert, Johnny Wilson, PhD, measuring the economic toll of lesser grain borer (LGB) activity on milling efficiency.

The full study, found here, was conducted by Dr. Jeff Gwirtz and the USDA Center for Grain and Animal Health Research in Manhattan, KS regarding the importance and value of insect control in the milling process. In our first blog exploring the study, we discussed why insect control matters in milling.

Now, let's take a deeper dive into the real-world implications of unchecked insect infestations.

A Controlled Study, Real-World Implications

To better understand how infestation affects output, researchers analyzed hard red winter wheat samples with varying levels of LGB infestation over a 9-week storage period. The study was designed to replicate real-world conditions and measure impacts across different stages of grain processing. Even modest levels of infestation had measurable effects.

Numbers That Tell the Story

The study found that flour yield declines as insect infestation levels increase. When hard red winter wheat samples were processed, the control group with no infestation produced the highest flour yields across all measurement methods. In contrast, samples with low, moderate, and high levels of LGB infestation showed progressively lower flour yields, underscoring the negative impact of infestation on processing efficiency. 

In addition to reduced yield, dry matter losses during storage were measurable and increased with insect density.

Table 2 of the study shows that milling with all material (including insect-damaged kernels and broken grains) results in higher losses and contamination. The low-infestation group lost 0.22% of dry matter and the high-infestation group lost 0.5%.

Moisture content also rose slightly during storage, likely influenced by higher relative humidity, but the increase was more pronounced in the infested samples, which may suggest an indirect impact from insect activity.

When comparing the control wheat to infested samples, the study found that typical cleaning processes failed to remove all insect debris. This contaminated material would not be suitable for milling under food-grade standards.

To estimate the full extent of infestation-related impact, Table 3 reflects what happens when this contaminated fraction is excluded entirely from the milling process. Removing infested material may protect flour quality, but it also leads to substantial raw material loss, further reducing overall yield and profitability.

This research makes the case for proactive, facility-wide insect control. Visit our product page here for information to help you implement a proactive solution, or contact a representative in your area to talk through the solution that’s right for you.

Stay tuned for our next blog in this series, where we’ll dive deeper into the economic impact of these findings and strategies for preventing costly losses before they start.

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