Red Flour Beetle: Control of Red Flour Beetles, Grain Pests

Control infestations of Red Flour beetles with a combination of thorough sanitation procedures and crack and crevice pest control procedures. Appearance, habits and pest control measures for this pantry pest are much like those outlined for the Confused Flour Beetle.

Red Flour Beetle: Biology, Identification, Elimination

Description: 1/8” long; are flat, shiny, reddish-brown and elongated. Last segments of tip of antennae are abruptly larger than the preceding ones, forming a three-segmented club. The Red Flour beetle has a curved thorax. Eggs of the beetle are whitish or colorless and microscopic in size with food particles adhering to the sticky surface. Beetle larvae are brown-headed with cream to yellow slender and wiry body reaching a length of 1/4” with six legs and two pointed or forked projections at the last rear body segment. Pupae are white to light brown.

Biology: Known as “bran bugs”, Red Flour Beetles mainly attack milled grain products such as flour and cereals. They also feed on grain dust and broken kernels, but not the undamaged whole grain kernels. They often enter a home in infested flour and can multiply into large populations. They survive on food accumulations in cabinet cracks, crevices and furniture.

Life Cycle and Habits: Female Red Flour beetles lay 300 to 400 eggs each in flour or other foods during a five to eight month period. Within 5 to 12 days the eggs hatch into slender, cylindrical white larvae tinged with yellow. The life cycle stage from Larvae to adult requires 7 to 12 weeks with adults living for 3 years or more. Adults can be found either on the surface or deep within the food material and can frequently invade storage containers. Red Flour Beetles breed in damaged grain, grain dust, high-moisture wheat kernels, and flour and have been found in barley, breakfast cereals, corn, cornmeal, crackers, flour, millet, oats, rice rye, wheat and wheat bran, nutmeats, dried fruits, legume seeds, beans, milk chocolate, cottonseed, peas, powered milk, sunflower seeds, vetch seeds, spices herbarium and museum specimens and even baits poisoned with arsenicals.

Control Measures: Dispose of infested foods in wrapped, heavy plastic bags or in sealed containers. Examine foods like flour, pancake flour, cornmeal, cereals, raisins, dry dog and cat food, spices, candy, dates, dried meats and fruits, rice, and macaroni at the time of purchase. Store susceptible foods in insect-proof containers of glass, heavy plastic or metal to prevent infestations or cross infestations of Red Flour beetles from one stored product to another. Lightly heat infested or foods suspected to have infestations in shallow pan in the oven at 120 degrees F for one hour or at 130 degrees F for 30 minutes. Place in a deep freezer at 0 degrees F for four days, or heat in a microwave oven for five minutes. Sifting the food material will remove possible insect fragments, and any remaining beetle fragments will not cause harm if consumed. After removing all food, food packages, utensils, dishes from cupboard, shelves or storage area, use a strong suction vacuum cleaner with proper attachments to clean all spilled foods from the cracks and crevices, behind under and in appliances and furniture. Scrub with soap and hot water. Cover with clean fresh paper or foil before replacing with food or cooking utensils. Household insecticides have no effect and are not to be used on insects within food packages. For extra protection treat seeds or grains before storage with dusts or spays of synergized pyrethrins labeled for this use.

Heavily infested areas can be treated with proper insecticides and safe pest control techniques. Adult and immature stages of beetles as well as possible food sources of Red Flour beetles and other stored product pests, pantry pests, can be removed by thorough vacuuming and cleaning. Any possible insects that remain hidden in cracks and crevices can be treated with crack and crevice aerosols labeled for such use. Synergized pyrethrin aerosols and Baygon Aerosol are products used for crack and crevice work. Pyrethrins give a quick knock-down of insects in cracks and crevices (places where beetles, weevils, roaches, insects hide) without leaving behind a pesticide residue. Baygon is a crack and crevice aerosol that will provide some residual activity, lasting about 2 weeks on average.
Chemical and non-chemical control measures for Red Flour Beetle infestations parallel those used in managing Confused Flour beetle populations.
Flour beetle control products listed will work for Confused Flour Beetles, Red Flour Beetles and other similar pantry pests. Control products listed are especially helpful when faced with either stubborn pantry pests (stored product pests) or situations where pantry pests such as Red Flour Beetles are a common, reoccurring insect problem.
The sensitive areas where stored food pests are found dictate that sound, integrated pest management procedures are followed.
Always begin with a thorough inspection of the immediate and nearby areas to determine size of population, sources of infestation and all possible areas where the insects have been seen or where they might next spread.
Disposing of infested materials is your next integrated pest management step. Once these grains have been discarded properly, other similar materials in the vicinity should be stored properly to protect them from possible infestation. After foods and grain materials have been stored or protected all areas are to be vacuumed and cleaned to eliminate all possible sources of insect foods and all remaining stages (adults and immatures) of beetles or weevils.
It is at this point where you can determine whether or not pest control products are needed. Pest control products can be used for knock-down of remaining bugs and for prevention of reinfestations. These products can also be used to contain the problem, preventing the bugs from spreading to other areas of the structure.
The design of the structure, size of pest populations and chances of pests re-infesting the structure will determine which types of chemicals (if any) are needed.
Pyrethrin aerosols can be used for quick knock-down of the offending pest. Pyrethrins will not leave behind any residue, normally lasting no longer than a few hours. A Baygon aerosol can be used in cracks and crevices (same areas where Pyrethrin aerosols are used) but Baygon is a residual pesticide. This means that the killing power will remain in beetle hiding places for as long as two weeks. Any Baygon residue should be cleaned off of food preparation areas. You only want this residual to remain in areas where pests are most likely to hide and where humans and foods will least likely to come into contact with the product.
For stubborn infestations and for long-term prevention of infestations, many professionals are turning to insect growth regulators (IGR) as a less invasive yet effective means of control. An IGR that contains Hydroprene is used for this job, as outlined in the beetle control article.
Many pest professionals will spot treat baseboards, certain storage areas and the flooring beneath pallets with an odorless, long residual product such as Suspend SC. This residual spray kills bugs that crawl over treated surfaces.

Thanks to Lani Powell, whose research made this Red Flour Beetle information and beetle control page possible!