Red flour beetle

Structure, Appearance and Characteristics

Adults:

• Small reddish brown in colour.
• Grooved wing covers.
• Size ranges from 2.3 to 4.4 mm in length.
• Can fly short distances under warm conditions (not below 25 C).
• Antennae ending in a distinct 3-segmented club.
• Chewing mouthparts.
• Can be confused with the Confused Flour Beetle (Tribolium confusum). The antennae of the red flour beetle are abruptly club-like with a three segmented club whereas the antennae of the confused flour beetle are gradually club-like with a four segmented club.  The sides of the thorax of the red flour beetle are curved whereas those of the confused flour beetle are somewhat straighter.

Laveae (the young):

• Larvae are about 6mm long, white or yellowish in colour, with dark head, and 3 pairs of legs.
• Two-pointed or forked termination in last segment of body.
• Chewing mouthparts.

Life Cycle

• Complete metamorphosis.
• Average oviposition period 5.5 months.
• Female can lay from 2 to 20 eggs per day and 300-400 eggs as an average total.
• Eggs are whitish or colourless and adhered to flour particles by sticky exterior.
• Incubation period for eggs is about 9 days at room temperature.
• Number of larval instars can range from 5-18, commonly 7 or 8, depending on environmental conditions.
• Larvae remain external to the grain.
• Larval period length varies from 22 days to more than 100 days.
• Pupal period approx. 8 days at room temperature.
• A new generation is completed in 4 weeks at 30 degrees C and in 11 weeks at 22 degrees C but cannot will not be completed at temperatures less than 20 degrees C.
• Adults can live for more than 3 years, average life of 200 days.
• Under optimum conditions, adult population can multiply 70 times within 4 weeks.

Habitat

Insect of warmer climates. Found in cereal mills, food processing plants, grocery stores, domestic households, ships.