Field plate · Stegobium, Lasioderma, Tribolium spp.
Stored-product beetles
Small beetles in the flour, the spice rack, the dog food. The moth plate tells you to inspect the packets — these are what you often find when you do.
Plate 27 of 28. Drawn in profile to the identification marks named below; the scale rule is a drawing convention — sizes are given in the text.
Identification marks
Drugstore and cigarette beetles: 2–3.5 mm, oval, brown, hump-backed in profile, grooved wing covers; drugstore beetles bore neat round exit holes in packages. Flour beetles: 3–4 mm, slender, reddish-brown, found moving through flour and grain products, which take on a sharp, off smell when numbers build. All are found in a food, not just near it — that is the identification.
Look-alikes it is confused with
Indianmeal moth larvae (the pantry moth's caterpillars web across the surface of a food — beetles tunnel inside it), carpet beetle larvae in stored wool (a different cupboard entirely), and harmless beetles that wander in from outdoors in autumn. If it is inside a sealed-ish package of food, it is a stored-product pest until shown otherwise.
Where it hides in a house
The pantry, in the oldest packages: flour, cereal, spices (paprika and chilli are classics), dried fruit, nuts, pet food and bird seed, cake mixes, and the forgotten bag at the back. One infested package seeds the shelf; beetles chew through paper and thin plastic to reach the next.
Health & property risk, stated plainly
Spoiled food and wasted groceries, not disease. Infested food is discarded — not because the beetles are poisonous, but because the food is no longer food in any sense worth keeping.
What actually works
The purge, done completely: pull everything from the shelf, inspect every package against the light, discard anything infested (sealed in a bag, out of the house), and vacuum the shelf's cracks and shelf-pin holes where larvae pupate. New dry goods go into glass or hard plastic with tight lids. Goods you are unsure of can be frozen at 0 °F for four days. Pheromone traps, where used, are monitors that confirm the purge worked.
What doesn't
Spraying the pantry — insecticide does not belong where food is stored, and it cannot reach beetles sealed inside packages anyway. Also: saving the 'good half' of an infested bag, and restocking the shelf the same day without the vacuum pass.
When to call a licensed pro
When beetles keep appearing after a full purge — the source is then something structural in your stores: a spilled reservoir behind the cabinet, a wall void full of old seed, or a bulk bin. Restaurants and food storage have regulatory reasons to call sooner.