The Beetle That Can Chew Through Poison and Packaging Alike

Pantry moths and weevils aren't the only insects that turn up in stored dry goods. Drugstore beetles (Stegobium paniceum) and cigarette beetles (Lasioderma serricorne), both in the beetle family Anobiidae, are a genuinely different kind of stored-product pest, with different biology and a different way of actually getting into packaging in the first place.

How the drugstore beetle got its name

The drugstore beetle earned its common name from historically being found feeding on the dried herbs and plant-based medicinal material that old-fashioned pharmacies kept in stock. What makes that more than a quaint bit of naming trivia is just how indiscriminate its diet actually is: drugstore beetles have been documented feeding on genuinely poisonous substances, including strychnine and belladonna — material that would be lethal to most animals that ate it. That's a useful illustration of exactly how broad and non-selective this insect's feeding habits are.

Telling the two beetles apart

Drugstore and cigarette beetles look similar enough to be mixed up, but there's a reliable way to tell them apart. The drugstore beetle is roughly 2.5mm long, cylindrical, uniformly brown, covered in fine hairs, with visible grooves running lengthwise along its wing covers, and antennae that end in a distinct three-segmented club. The cigarette beetle is slightly smaller, has smooth wing covers with no grooves, and — the clearest giveaway — antennae that are serrated, notched like the teeth of a saw, rather than clubbed.

An unusually broad diet for both

Both species feed on an extensive range of dried plant and animal material: cereals, pasta, spices, dried fruit, tobacco products, and dry pet food are all documented food sources. The cigarette beetle in particular is considered a major pest of dried spices and herbs specifically, which is why these two insects turn up in kitchen spice racks and dried-goods storage far more often than in, say, a bag of fresh produce.

The detail that sets them apart from pantry moths and weevils

Pantry moths and weevils typically get into stored food through small existing gaps, or arrive already present inside a product from earlier in the supply chain. Drugstore and cigarette beetles do something the others don't: they can physically chew through packaging. Adults emerging from an already-infested product will chew their way out, and larvae can bore and burrow new holes directly into packaging material, leaving behind large, round holes that weren't there originally. That means an intact-looking, factory-sealed box or bag isn't automatically a guarantee of safety the way it might be against a moth or weevil getting in from outside.

• Check stored packaging for small, round holes rather than just torn seams or gaps — that specific damage pattern points to these beetles rather than moths or weevils.
• Pay particular attention to dried spices and herbs, since cigarette beetles are a well-documented pest of exactly those products.
• Don't assume a sealed container is immune just because it looks undamaged from the outside — these beetles are capable of chewing their own way in or out.
• Check antennae shape if you need to tell the two species apart specifically: a three-segmented club points to a drugstore beetle, a saw-toothed (serrated) antenna points to a cigarette beetle.
• Discard infested packages rather than trying to salvage them, and check nearby stored dry goods too, given how broad both species' diets actually are.

Because these beetles can get into packaging that looks completely intact, a pantry problem involving them is often more widespread than the one damaged box that first gets noticed. A free Sevacorp inspection can help confirm what's actually present and how far it's spread through stored goods.

• Sources:
• Clemson Cooperative Extension (HGIC) — "Drugstore Beetles" — https://hgic.clemson.edu/factsheet/drugstore-beetles/
• Penn State Extension — "Drugstore Beetle" — https://extension.psu.edu/drugstore-beetle
• Virginia Cooperative Extension — "Drugstore and Cigarette Beetles" — https://www.pubs.ext.vt.edu/3101/3101-1526/3101-1526.html
• Texas A&M AgriLife Extension (citybugs) — "Cigarette and drugstore beetles" — https://citybugs.tamu.edu/factsheets/household/food-fabric/ent-2004/