A to Z of Pests

Lesser Mealworm

Alphitobius diapernis

Appearance

• Adults - 6 mm long. Newly moulted adults are reddish-brown turning black.
• Larvae - 7.5 mm long. Slender, segmented and worm-like with three pairs of tiny legs on the thorax and one abdominal proleg at the rear.

Lifecycle

• Females can lay up to at least 110 eggs a month and eggs hatch in 4-7 days.
• Larval development takes up to 7 weeks. Mature larvae seek a sheltered place to pupate for between 7 and 11 days.
• An adult beetle may live up to two years.

Habits

• The beetles are attracted to poultry operations, which have ideal conditions for their development. The damage to insulation is carried out by lesser mealworms seeking a safe place to pupate because the darkling beetles prey on the lesser mealworms.