Flour Beetles
Flour beetles are small, reddish-brown beetles that are among the most common stored product pests in homes and commercial flour mills. The red flour beetle and confused flour beetle are nearly identical in appearance and behavior. They infest flour, cereal, pasta, baking mixes, spices, and a wide range of other grain-based products. Unlike grain beetles that attack whole kernels, flour beetles feed on broken grain, flour, and processed cereal products. They are long-lived insects, with adults surviving one to three years.
Species in This Group (2)
Red Flour Beetle
Tribolium castaneum
The Red Flour Beetle is a major pest of stored flour and grain products worldwide.
Confused Flour Beetle
Tribolium confusum
The Confused Flour Beetle is nearly identical to the Red Flour Beetle in appearance and habits.
Key Behaviors
Flour beetles cannot attack whole, undamaged grain but thrive in flour, meal, and processed products. They produce secretions that give infested flour a pungent, disagreeable odor and taste. Large populations turn flour pinkish. They are active crawlers found on shelves and countertops and can fly in warm conditions. Red flour beetles fly readily while confused flour beetles are weaker fliers.
Risks & Concerns
Flour beetles contaminate stored food with secretions that impart a foul taste and promote mold growth in flour. Their secretions contain benzoquinones, which are carcinogenic at high concentrations. Infested products must be discarded. In commercial settings, flour beetle infestations can shut down milling and baking operations. Their long adult lifespan means populations persist even after food sources are removed.
Quick Comparison
| Species | Size | Color | Key Trait |
|---|---|---|---|
| Red Flour Beetle | 3-4 mm | Reddish-brown | Small, flat, reddish-brown beetle found in flour and grain products; antennae gradually enlarge into a 3-segmented club. |
| Confused Flour Beetle | 3-4 mm | Reddish-brown, nearly identical to red flour beetle | Nearly identical to red flour beetle; distinguished by abruptly enlarged 3-segmented antennal club; cannot fly. |
Need Help With Flour beetles?
If you're seeing signs of flour beetles in or around your home, professional treatment is the fastest way to stop the problem. Lotus Pest Control offers free inspections to identify the issue and recommend the right solution.