Merchant Grain and Sawtoothed Grain Beetle

Merchant grain and sawtoothed grain beetles are so similar, they were considered to be one species in the past. They are around 1/8″ long, brown, with saw-like teeth on their sides. Adult merchant grain beetles are attracted to light and can fly, whereas sawtoothed grain beetles don’t do either one. Sawtoothed grain beetles are considered to be a bigger pest of stored products overall. Larvae are the same size as adults, and feed on the same types of products, though they will leave whole grains alone. Things they both feed on include cereal, popcorn, rice, flour, nuts, dried fruits, spices, and dog food. Merchant grain beetles prefer oilseed products. Nuts, cereals, and cookies are some of their favorites. Both types of beetles can chew through, and work their way into many types of sealed packaging. Cardboard, plastic, and foil don’t always stop them from getting to the food inside.