What do flour beetles eat

Two of the most common flour beetles are the confused flour beetle, Tribolium confusum duVal , and the red flour beetle, Tribolium castaneum Herbst. These are small beetles. There are differences between the antennae of these two beetles. Since these insects are so small, it usually requires a magnifying glass to recognize these differences. Flour beetles are pests of flour and cereal products. They are among the most important pests of flour and stored products.

They are common in homes and grocery stores. They also infest mills and food processing facilities. The flour beetles include several species. Some of the other flour beetles are the black flour beetle, the false black flour beetle, the broadhorned flour beetle, the slenderhorned flour beetle, the depressed flour beetle, the smalleyed flour beetle and the longheaded flour beetle.

These do not occur as often as the red and the confused flour beetles. The red flour beetle originally came from Asia. In the United States it is most common in the South.

The red flour beetle is a good flier. It sometimes flies from fields into buildings. Some people suspect that the confused flour beetle got its name from being confused with the red flour beetle.

The confused flour beetle originally came from Africa. They will use their wings to fly short distances.

Red flour beetles have distinctive antennae that abruptly end into an enlarged three-segmented club. The red flour beetle and the confused flour beetle are both flour beetles but are considered to be different species.

Both are pests that infest flour and cereal products and invade and become problematic in homes, grocery stores, mills and food processing plants. But the red flour beetle originally originated from Asia, while the confused flour beetle originated from Africa. In fact they are so similar appearing that it is almost impossible to tell the two apart except under a magnifying glass.

The red flour beetle is of Indo-Australian origin and now occurs worldwide in the warmer climates. In the United States, it is found primarily in the southern states in homes and grocery stores. The most common signs that red flour beetles have invaded your home is to see the actual beetles either crawling or flying throughout your home, or by seeing them in your flour or cereal products.

You may also notice holes where they have chewed through the packaging of flour or other dry cereal products that are stored in your kitchen or pantry areas. In the United States, it is found primarily in the southern states. The confused flour beetle, originally of African origin, has a different distribution in that it occurs worldwide in cooler climates. In the United States it is more abundant in the northern states Smith and Whitman.

Figure 2. Adults of the confused flour beetle, Tribolium confusum Jacquelin du Val, shown on a kernel of corn. The red flour beetle is reddish-brown in color and its antennae end in a three-segmented club Bousquet Whereas the confused flour beetle is the same color but its antennae end is gradually club-like, the "club" consisting of four segments Walter. Figure 3a. Three-segmented antennal club of the adult red flour beetle, Tribolium castaneum Herbst.

Figure 3b. The head of the red flour beetle is visible from above, does not have a beak and the thorax has slightly curved sides. The confused flour beetle is similar, but the sides of the thorax are more parallel Anonymous Figure 4. Comparison of adults of the red flour beetle left , Tribolium castaneum Herbst and the confused flour beetle right , Tribolium confusum duVal.

The antenna of the red flour beetle ends in a 3-segmented club and the sides of the thorax are slightly curved. The confused flour beetle has no apparent club on the antennae and the sides of the thorax are straighter. Graphics by USDA. These two beetles are in the family Tenebrionidae and have a tarsal formula of and notched eyes.

Figure 5. The front left , middle middle and hind right legs of the red flour beetle, Tribolium castaneum Herbst , showing the tarsal formula. The confused flour beetle, Tribolium confusum Jacquelin du Val, has the same tarsel formula.

Photographs by Rebecca Baldwin, University of Florida. Figure 6. The head of a red flour beetle, Tribolium castaneum Herbst , showing the notched eye. The confused flour beetle, Tribolium confusum Jacquelin du Val, also has the notched eye. Photograph by Rebecca Baldwin, University of Florida. The red and confused flour beetles live in the same environment and compete for resources Ryan et al.

The red flour beetle may fly, especially before a storm, but the confused flour beetle does not fly. They are found in stored food products like flour, cereals and other products e. Adults and larvae feed throughout stored food, primarily in milled or prepared products. They are perhaps the most common pest of processed flour. These species are often used as a test animal in laboratory experiments because they are easy to keep in culture.

These insects are found world-wide infesting stored food; infestation may affect the flavor of product. They are medically harmless, even if eaten. The confused and red flour beetles cannot feed on whole undamaged grain; they are scavengers, they feed on grain materials damaged by other pests or during transportation or storage.

Both types of beetles are often found not only in infested grains, but in crevices in pantries and cabinet, as well. Damage to food is caused somewhat by the beetles feeding, but also by their dead bodies, fecal pellets, and foul-smelling secretions. In addition to creating a foul odor, the beetles presence encourages the growth of mold.

Adult beetles are active and move about irregularly. They can live for over a year. Eggs laid by females hatch in 5 to 12 days. Larvae are white, tinged with yellow, slender and cylindrical. They have two short appendages on the end of the last abdominal segment.

There may be 5 generations per year. Females may lay up to 1, eggs during their life span, which may last several years under ideal conditions. Because adult red flour beetles are very active, can fly, and are sometimes attracted to light, they disperse easily from their initial infestation point.