The Life Cycle of Tribolium

Understanding the life cycle of the Tribolium beetle species can help in getting rid of an infestation. The confused flour beetle (Tribolium confusum) and the rust red flour beetle (Tribolium castaneum) have similar life cycles where the beetles go through a larva, pupa, and adult stage. The beetle looks different in each stage but all ages must be disposed of to get rid of an infestation. These beetles are often found in storage containers of grain, flour, breakfast cereals and spices.

Birth

The Tribolium beetle, like all insects, hatches from an egg. The Tribolium egg is colorless and microscopic. The egg's surface is sticky though and food particles can stick to its surface. Eggs can be laid in the crevices of packaging materials or among the food source itself. A female beetle can lay two to three eggs per day over a period of several months. After she lays the eggs they will hatch within five to twelve days.

Larva Stage

From each egg hatches a beetle larva. The larvae are slender, cylindrical and are a cream or yellow color with brown heads. Each larva has six legs with two forked projections at the rear. Insects generally grow through molting, a process where the insect sheds its exoskeleton and grows a new one. During this stage the Tribolium beetle will molt as many as 12 times growing up to a length of one-quarter inch. The larva period can last from 22 to 100 days depending on food supply and how quickly the larva can grow.

Pupa Stage

The pupal stage is where the beetle metamorphoses from a larva into an adult. In this stage the beetle is dormant and not eating as all energy is put into the metamorphoses. In the Tribolium species the pupa stage generally lasts about eight days. The Tribolium has a naked pupa stage, meaning there is no cocoon.

Adult

An adult Tribolium beetle will shed its pupa covering and emerge very hungry. Both the confused and red flour beetles are flat, shiny, and brown as adults with antennae and six legs. The red flour beetle can fly, however the confused beetle cannot. An adult beetle can live up to three years and a female can lay 300 to 400 eggs in a lifetime.

Death

Eventually the beetle will die, however, people suffering from a beetle infestation may want to usher beetles to their deaths a little faster. Insecticides are generally discouraged around food materials and the best way to deal with an infestation is to throw away infected materials. Be sure to use a heavy, sealed plastic bag or bury the food in permitted areas. Also a good idea is to cook the food to kill the bugs and use the grains in bird feed.

References

• Confused and Red Flour Beetles
• Confused Flour Beetle

Resources

• Process of Insect Molting
• Pictures of Flour Beetle Life Cycle