Stored Product Pests

There are three main Stored Product Pests common to Northwest Residences: Drug Store Beetles, Cigarette Beetles and Indian Meal Moths. First, we will visit each pest's biology and then we will treat accordingly to control each pest's specific habits and routines.

Drugstore Beetle

The Drug Store Beetle derives its name from its habit of infesting certain pharmaceutical materials. Its name not withstanding, the Drug Store Beetle has no primary food preference. The Drug Store Beetle can survive on strychnine, arsenic, etc. That should give you an idea of what kind of diet this pest keeps! However, Drug Store Beetles will feed on most any dry stored food product, especially those high in starch such as noodles, crackers, flour, rice, etc. They eat only during the second of the four stages of their life cycle: egg, larva, pupa, adult. The larvae emerge from the eggs to feed for a period of 2 to 4 months (depending on environment). Larvae then crawl out of the food source to pupate. During pupation, the larva envelops itself in a cocoon and once the pupation has completed, a fully matured adult is produced. The adult is 2 to 3mm in length, red to reddish-brown in color and (when viewed under a microscope) the hairs of its wings are arranged in rows running from the head to the opposite end of the abdomen.

Cigarette Beetle

The Cigarette Beetle gets its name from its tendency to infest dried tobacco products as well as chewing tobacco. It is another Stored Product Pest known to feed on a wide range of materials - of which, the majority are dry, stored foods. In fact, some were found infesting dried resin from the tomb of Egyptian King Tutankhamun. The Cigarette Beetle has the same basic biology as the Drug Store Beetle. They are the same color, approximately the same size, and they can be differentiated only when viewed under a microscope.

Indian Meal Moth

The Indian Meal Moths are winged pests. They present the same sort of danger to stored products as the two beetles discussed above. They feed on flour, meal products and grain products. Indian Meal Moths will also infest some paper products. They feed only during the larval stage and they leave webbing material behind in the food source. The presence of this webbing material is one way to determine that Indian Meal Moths are present. Their eggs are laid on a palatable food source where they become larvae, feed and then crawl away to pupate. Their cocoons can usually be found at the intersection of the ceiling and walls in a food pantry. Adults are about ½ inch long, gray in color and have wings.

Control Measures

The control measures for these pests are simple to understand and are the same for all of them: locate and remove the food source. Though it is a simple solution, it requires taking everything out of suspected storage areas (including those surrounding the targeted area) and inspecting each item thoroughly. This is a time-consuming endeavor, but it is the only sure way to control these pests. Knowing what to look for in the items as you inspect is the most important thing. For Indian Meal Moths, look for webbing. Beetles will bore through the food leaving many small holes and fine dust. Having removed the food source, the cracks and crevices of the affected area should be treated with a residual pesticide designed for use in food storage areas. Lures, such as reproductive pheromones, can provide a chemical free treatment option for Indian Meal Moths.