Biscuit or Bread Beetle

Which insects look like the bread beetle and how to tell the difference?

1. Cigarette beetle (Lasioderma serricorne): The biscuit beetle and the tobacco beetle can hardly be distinguished from one another in terms of appearance.

Under high magnification, you can spot small differences: the body of the biscuit beetle is covered with short yellowish brown hairs, the tobacco beetle is hairless. Bread beetles have grooved wing cover and a 3-segmented club at the antenna tip, whilst the cigarette beetle has saw-toothed antennae.

2. Flour beetles (Tribolium spp.) are longer, flatter and more chestnut-brown. Their antennae end in a club. They cannot attack whole grains, so flour beetles are found in flour, semolina, cereals and spices.

3. Sawtoothed/merchant grain beetle (Oryzaephilus spp.) – Thin, very flat beetles with obvious “saw‑like” teeth on the sides of the thorax. These grain beetles are active runners that don’t fly, whereas the bread beetle does fly. Common in processed foods.

4. Furniture/woodworm beetle (Anobium punctatum) – A true wood borer (3–7 mm). Creates round holes and powdery frass in timber. If the damage is in wood—not food—it’s not a bread beetle.

Why do you get bread beetles and how do they get into your storage?

Stored product insects sometimes seem to appear out of nowhere but that is not the case. These are the main reasons why you get pantry beetles:

• Infected incoming goods: the most common cause. Eggs or larvae are already inside the product (dry foods, spices, pet food or botanicals), develop and spread to other food.
• Open or unsealed packaging: adults and larvae can chew through paper, plastic and thin foil to fly out or get access.
• Via internal movements between storage, processing and packing areas, due to poor rotation or long dwell times that increase the risk.
• Flight: adults fly inside, attracted by lights, get 'stuck' or look for a breeding spot to lay off eggs.

Natural and safe ways to get rid of bread beetles

1. Find and remove the root cause or source: systematically check all dry foods, old packaging of starch-rich products, pet food, spices or botanicals. Discard anything with live insects, cocoons or exit holes.

2. Deep clean: vacuum shelves, cracks, pallet bays, racks in the disinfected areas, floor edges, empty and clean adjacent cupboards, behind or under equipment, dispose of dirty or infested contents immediately.

3. Freeze or heat or small infestations: 50 to 65°C for sufficient time to reach the core to eliminate eggs and larvae or freeze to -18°C for at least 4 days or longer for dense packages. Thaw sealed to avoid condensation. Always verify product safety first.

4. Repackage clean product: move safe product into airtight, pest-proof containers or safe areas.

5. Review stock flows and storage procedures: shorten storage times according to the FiFo-principle, reduce mixed or open bulk containers, etc.