The red flour beetle (Tribolium castaneum) is a reddish-brown pantry pest about 3–4mm long that infests flour, cereals, spices, dried fruit, and baking mixes in Arizona homes. Unlike the confused flour beetle it closely resembles, the red flour beetle can fly — making it capable of spreading between rooms and even between neighboring units in apartment buildings. Both adults and larvae feed on grain products and secrete quinones that discolor and taint infested food with a bitter, musty odor. The red flour beetle is also a secondary pest, meaning it can infest grain products that have already been damaged by other insects or moisture.

Controlling red flour beetles in Arizona requires the same systematic pantry cleanout approach used for other stored-product pests: inspect every item, discard infested products, vacuum all surfaces, and transfer dry goods to airtight containers. Because red flour beetles can fly, check adjacent rooms and cabinets beyond the main pantry — adults are attracted to light and may be found near windows. Pheromone traps are particularly useful for red flour beetles because their pheromone is well-characterized and commercially available. Place traps in the pantry and in adjacent rooms to monitor the extent of the infestation.

Arizona's warm climate allows red flour beetles to reproduce year-round, with the life cycle completing in as little as 5–6 weeks at summer temperatures. The ability to fly makes red flour beetles harder to contain than non-flying pantry beetles — a single infested bag of flour can seed an infestation throughout a kitchen within weeks. If cleanout and pheromone traps do not resolve the problem within a month, professional inspection is recommended. Pest Control Bros LLC provides pantry pest control throughout Maricopa, Chandler, Mesa, Tempe, Gilbert, and Casa Grande. Call (520) 424-5244.