4954 N. Shamrock Place, Tucson, AZ 85705

Red Flour Beetle

Tribolium castaneum

Red Flour Beetle

Physical Features

Red flour beetles have three body parts, six legs, antennae, and reddish-brown coloring in the adult stage.  The larva are white with brown head and forked projection at the rear. The adults have notched eyes and 3 segmented club at end of antennae.  Thorax is rounded.  The adults are 1/8 inch long and are able to fly.

Life Cycle

Development takes 30-90 days (average begin 30 days in prime conditions) from egg, larva, pupa, to adult forms.  The adults can lay 300-400 eggs during a 5-8 month period.  The eggs are covered with a sticky substance so when eggs are laid in the food source, the food residue will stick to the egg making it harder to detect.


  • Diet: Grain products including cereal, pasta, dry pet foods, cake mixes, spices, dried flowers, seeds, nuts, flour, wheat, oats, etc.
  • Activity: Day and night
  • Preferred Climate: Warmer climates.
  • Defense: Inspect grain products before moving into the house.  Store in freezer for one week before placing in the pantry.  Store products in tightly sealed containers and inspect each time used.
  • Cautions: Can destroy grain products but are not known to spread disease.
  • Home Invasion:  Adults or larva can be seen in products or in the vicinity of where they are stored.

Helpful Hints

  • Find food source and dispose of it immediately.  Look through all products in the vicinity to ensure infestation has not spread to other items even if you think you found the main source.
  • Sanitation practices to eliminate food sources including vacuuming food residues and beetles then discarding vacuum contents in outside receptacle.
  • Use hot water with bleach to remove any remaining food residues on shelves or food packaging.
  • Insecticide applications and pheromone lures are available, but sanitation is the key to solving this problem.

Interesting Facts

Another pest called Confused flour beetle often is “confused” for the Red flour beetle.  They have many of the same attributes, however, confused flour beetles cannot fly.