Sawtoothed and Merchant Grain Beetles
One of the more common pantry insects, Saw-Toothed Grain Beetles and Merchant Grain beetles adults are small, slender insects which may occur in both food products in the pantry area and in other adjacent rooms. These are scavenger feeders which means that you are not likely to find them in whole grain products.
Foods that may be infested include hot and cold cereals, flour, pastas, dried fruits, dried meats, chocolates and other similar products. As with other pantry insects, it is the larvae do most of the damage, yet it is the adult that is most commonly found by consumers. Due to the adaptation of teeth on the sides of the pronotum (the area behind the insect's head - see photo at top), the adult can enter sealed cardboard boxes and soft plastic packages.
There is a very slight difference in appearance between these two insects, but the Merchant Grain Beetle flies while the Saw-Toothed Grain beetle does not.
How to Deal With An Infestation
Control of these insects involves inspection and removal of infested food products. Remember to check even unopened packages. Once inspected, it's a good idea to transfer product into impervious containers such as Tupperware©, Rubbermaid© or other plastic, glass or metal containers or tins.
Vacuuming the corners of shelves using a crevice tool is also suggested followed by sealing and disposing of the vacuum bag.
Finally, application of a residual insect spray such as Permacide P-1 to the corners of cabinets using a pin-stream (jet) application, will help stop the cycle of these insects.
Many people express concern about applying insecticides where food or foodstuff is stored. Since the sprays are applied selectively to corners only and are permitted to dry before any food products are returned, these items are not at risk of being contaminated by the insecticide application. Remember too, that food products are almost always in containers and don't actually contact treated surfaces. Even with plates and dishes, only the bottom of these items touch the treated areas. Please read our commentary, Pesticides and Safety, for more information.
If you have any other questions or concerns regarding these insects pests or any other related question, please write to us at by clicking here or call us toll free, weekdays at 800-433-1128 or locally at 845-356-2837 between 8 am and 4 pm EST/EDT. Our fax number is 845-746-9018.