Stored food product or pantry pests include several beetles, moths and a mite that can infest whole grains or processed foods. Usually, the first sign of a problem is the appearance of small beetles crawling over counter tops, moths flying across rooms, or caterpillars crawling up walls or across ceilings.
These insects will be seen in several forms of the various life stages. The solution requires finding and destroying all infested products in which these pests have developed, a general cleanup, and use of sealed storage containers to prevent recurring problems.
Insects in the category of pantry pests include the granary weevil, rice weevil and the Angoumois grain moth. Other common pests include the red and confused flour beetles, saw-toothed grain beetles, drugstore beetle, cigarette beetle and Indian meal moth.
Cereals, rice, grains, flours, meals and similar products are often sources of these insects. A much larger number of insects feed on processed grains or broken kernels, or a variety of spices. Other places these insects take up residence are in dried fruits, dry dog food, dried meats, candy bars, drugs, tobacco, and a variety of other products.
The Indian meal moth is a very common household pest and the one I see often brought into the Extension Office. The distinctive 1/2-inch long adult is easily recognized by the pale gray and coppery brown front wings.
The dirty white to pink larval stage is a caterpillar that crawls away from the infested products to find a place in which to transform to the adult. The caterpillars feed on the surface and produce silk webbing throughout the food source.
The life cycle can be as short as 25 days. They can feed in dried fruits, powdered milk, chocolate, flour, meal, dried dog food, bird seed and a variety of food stuffs. They prefer coarse flours and corn meal.
While the adults and larvae of all of these different pantry insects are the signs of an infestation, merely killing them is not the solution. Infested food products must be found and destroyed. Identification of the pest can provide clues on where to look, but some of these insects can live on a wide range of materials.
In general, the greater the number of insects seen, the older the infestation. Often the initial source is partially used boxes or bags of products that have been forgotten in the backs of pantries and shelves. Or purchasing old, outdated food items or storing these items for a long time.
The infestation spreads as the active adults search for new food sources. A thorough search is needed to locate all infested items. If they are not found in our pantries or cupboards, then begin to look at such things as decorative items (like Indian corn), dry pet food or bird seed.
Disposal of infested materials is the best way to eliminate the problem. Be sure to check all items in pantries or on shelves. Often beetles can be found beneath cans and other items. Thoroughly vacuum the shelves, both upper and lower surfaces, and use a crevice attachment to clean cracks and crevices. It is better to do a very thorough job one time than to have to repeat a hasty inspection and cleanup.
After treatment, good sanitation and proper storage are keys to preventing future problems. Place products from cardboard, paper or plastic containers into jars or other containers that can be sealed tightly.
Decorative items such as Indian corn, dried flower arrangements or bird feed may be treated with heat (155°F for about 20 minutes with the oven door propped open) or in a non-self- defrosting freezer at 0°F for 4 days.
For more information, log on to http://www.ca.uky.edu/entomology/entfacts/ef612.asp or call the Extension Office and ask for information on stored grain pests in home foods. The Extension Office can be reached at 502-695-9035, or email DL_CES_Franklin@email.uky.edu.