Drugstore Beetle

Stegobium paniceum

Classification

Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Order: Coleoptera
Suborder: Polyphaga
Superfamily: Bostrichoidea
Family: Ptinidae
Subfamily: Anobiinae
Tribe: Stegobiini
Genus: Stegobium
Species: paniceum

Pronunciation

How to pronounce Stegobium paniceum: //stɛˈɡoʊ.bi.ʌm pəˈnɪ.si.əm//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Stegobium paniceum chili by Uwe1975. Used under a Public domain license.

Stegobium paniceum larve légende fr by author=* Simon Hinkley & Ken Walker (Musée Victoria - Melbourne - Australie)

derivative works: Omondi & Cymbella. Used under a CC BY-SA 3.0 license.

Stegobium paniceum-fr by Simon Hinkley & Ken Walker (Musée Victoria - Melbourne - Australie)
derivative works: Omondi (talk). Used under a CC BY 3.0 license.

Stegobium paniceum-Larve-fr by Simon Hinkley & Ken Walker (Musée Victoria - Melbourne - Australie)
derivative work: Omondi (talk). Used under a CC BY 3.0 license.

Stegobium-paniceum-07-fws by Francisco Welter-Schultes. Used under a CC0 license.

Brotkäfer-01 by Dat doris. Used under a CC BY-SA 4.0 license.

Summary

The drugstore beetle (Stegobium paniceum) is a small pest affecting a broad range of stored products, known for its vast evolutionary history and mutualistic relationship with yeast which aids in its survival. Its management has economic and health implications, necessitating safe pest control measures.

Physical Characteristics

Small reddish brown beetle ranging from 2.2-3.5 mm long with oval shape, rounded head, and dorsal plate bent forward. Antennae have a loose 3-segmented club, and body is covered in rows of pits giving it a striated appearance, longitudinal grooves on elytra.

Identification Tips

Distinguished from the cigarette beetle by its 3-segmented antennae that are more enlarged and distinct, and longitudinal striations on the elytra versus the smooth surface of the cigarette beetle.

Habitat

More abundant in warm regions or in heated buildings in temperate climates, commonly found in homes containing processed and packaged foods, as well as museum and herbarium specimens.

Distribution

Cosmopolitan, with higher prevalence in warmer climates; native to Europe and has adventively spread to North America (NA and CA to AK).

Diet

Larvae feed on a wide variety of materials including dried plant products, processed grains, chocolate, spices, tobacco, leather, wood, textiles, museum specimens; adults do not feed.

Life Cycle

Life cycle includes egg, 4-6 larval instars, pupal stage, and adult emergence; total duration typically 2-7 months depending on conditions.

Reproduction

Female lays up to 75 eggs, mostly in or around food sources. Eggs take about 7-20 days to hatch; optimal conditions speed development and survival.

Predators

Attacked by predators such as Tenebroides (Trogossitidae), Thaneroclerus (Cleridae), several carabids, and various parasitoid wasps (Pteromalidae, Eurytomidae, Bethylidae).

Ecosystem Role

Acts as a decomposer by breaking down dried organic materials; also has a mutualistic relationship with yeast.

Economic Impact

Significant pest of stored products leading to contamination and financial loss in food and pharmaceutical sectors.

Cultural Significance

Historically significant since the Bronze Age as a pest of stored food sources.

Evolution

Oldest known member from Late Cretaceous, with significant fossil records; evolved from a wood-feeding ancestor. Genome size between 238-345 Mb, smaller than median for Coleoptera.

Similar Taxa

Misconceptions

Commonly misidentified as a weevil (biscuit weevil), though it is not a true weevil.