Drugstore beetle
Stegobium paniceum (Linnaeus)

Classification

Secondary pest; Grain feeder
Order: Coleoptera
Family: Anobiidae
Acronym: SPA

Description

  • Adults are oval and 2.5 to 3.0 mm long.
  • Adults are reddish brown.
  • Adults can be distinguished from the cigarette beetle by the presence of a 3 segmented club on the antennae and the presence of striated elytra. The elytra are covered in fine hairs.
  • Adults are short-lived and feed little, if at all.
  • Adults are able to fly.
  • Larvae are white and covered in numerous hairs.

Similar species

Commodities affected

  • Spices, chocolate, seeds, flour, leather, feather pillows, dog food
  • Grain and cereal products

Signs of infestation

  • Contamination with larval cocoons
  • Damage by adults and larvae to food and packaging caused by holes associated with pupation
  • Contamination with larval cocoons, frass (excrement), dead adult beetles

Damage

  • Larvae cause direct damage to the commodity by feeding on it.
  • Larvae burrow into the food to pupate, causing irregular holes.
  • Adults chew holes in commodity packaging when emerging from pupa.

How to control

Geographic range

  • Is distributed worldwide, more often found in temperate climates
  • Occurs throughout Canada and can survive winter in unheated structures

Where found

  • May be found in dwellings, stores, bakeries, libraries, ships, mills, warehouses
  • Is a general feeder that attacks nearly all dry plant and animal material
  • Prefers vegetable matter that is rich in starch
  • Is of minor importance in stored grain situations
  • Is occasionally found in bee hives, feeding on pollen

Life history

  • Adult beetles run quickly and fly well.
  • Females lay eggs singly in crevices in the foodstuff.
  • Larvae are internal feeders and are mobile initially, becoming immobile as they mature, reaching a length of 3 to 4 mm.

Images

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