In the food processing industry, ingredients are the lifeblood of your operation. Each is a critical component of your end product.

But pests can see ingredients as their lifeblood, too. Not only can unprotected ingredients provide them with an endless meal, but pests can also use the containers for harborage. Worse yet, if left undetected, pests can breed and multiply to the point where they become an extra ingredient themselves.

Pest-infected ingredients can lead to a loss of product, safety and legal concerns and a major hit to your reputation and bottom line. The stakes are indeed high for brand protection.

Stored product pests can feed on a variety of ingredients in your facility’s storage areas including grains, beans, spices, nuts, dried fruits and cheeses. In addition to damaging your ingredients, many stored product pests can secrete chemicals that alter the taste of food, and their larvae can irritate the digestive tract or even cause allergic reactions. And since these pests reproduce quickly, it’s critical to address infestations in a timely manner.

That’s why it is of the utmost importance for food processing facilities to keep a keen eye on their suppliers’ operations and know how to spot incoming shipments for stored product pests both as soon as a new shipment arrives and throughout the product’s shelf life.

Different pests, different problems

The most common stored product pests are beetles and moths, which have long plagued granaries and other food storage facilities. The larvae of these pests, which can actually cause more damage to stored products than adult insects, range from 1/16-inch to a half-inch in size and feed on grain-based materials like flour, rice and noodles.

Based on their feeding habits and biology, stored product pests fall into one of four categories:

• External feeders feed on the exterior of the kernel or finished cereal product and work their way inside. Indian meal moths and cigarette beetles are well-known external feeders in bakeries.

• Internal feeders lay eggs within the grain and feed on kernels from the inside out. Common internal feeders include granary weevils, lesser grain borers and Angoumois grain moths.

• Secondary feeders consume moldy or damp products and, like external feeders, eat from the outside in. Both spider beetles and fungus beetles will feed on products in poor condition.

• Scavengers will eat almost anything, including grains that have been processed, broken or damaged by other insects. Scavengers, such as the red flour beetle and saw-toothed grain beetle, can be found in products ranging from cereals to chocolate.

One strategy, many tactics

Managing stored product pests takes a comprehensive strategy. Early detection, proper storage procedures and a comprehensive sanitation program are needed to help prevent these pest infestations. Work with your pest management provider to create an all-inclusive program focused on the following:

• Implement a stringent sanitation schedule to keep your facility free of food debris. Use a vacuum with a high-efficiency particulate air (HEPA) filter to remove debris from cracks and crevices, and immediately clean up any product spills. You can employ a continuous deep-cleaning program, preferably vacuum based, to ensure that every bay on every rack is inspected, vacuumed and wiped down completely at least twice per year.

• Inspect incoming shipments for signs of pests, such as webbing, larvae and live adult insects. You should also examine any packaging material for evidence of any damage. Monitor for potential infestations in shipments by keeping a quality assurance sample in a closed, labeled plastic container. If insects appear over time, immediately quarantine and inspect any remaining product and notify the supplier.

• Consider using temperature as a defense. Stored product pests cannot withstand extreme temperatures – either hot or cold. If possible, maintain storage rooms at 60 degrees F or lower. If this is not an option due to the size or layout of your facility, consider installing insulating walls and cooling a smaller area.

• Rotate ingredients on a first-in, first-out (FIFO) basis to help prevent them from deteriorating and becoming susceptible to an infestation. Store them off the floor and at least 18 inches away from walls to allow access for staff to inspect and clean the area. As a precaution, remove any products that are damaged or found in poor condition.

• Work with your pest management professional to monitor for stored product pest activity. There are several options a pest management professional can use to monitor and deter stored product pest activity. For instance, pheromone traps use synthetic reproductions of pheromones (chemical secretions insects use to communicate) to capture adult stored product pests. These traps can help evaluate pest activity, suppress pest populations and determine the timing for treatments. Using mating disruption pheromones can also eliminate moth pests, like the Indian meal moth.

Should stored product pests be found in your facility, immediately discard all products that appear to be infested and consult your pest management professional to help identify and treat the problem.

With a thorough and proactive pest management approach, you can help keep these nagging pests from damaging your ingredients, products, reputation and bottom line.

Zia Siddiqi is director of quality systems for Orkin. A board certified entomologist with more than 35 years in the industry, he is an acknowledged leader in the field of pest management. For more information, e-mail [email protected] or visit

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