Stegobium
Stegobium
Classification
- Phylum: Arthropoda
- Subphylum: Hexapoda
- Class: Insecta
- Order: Coleoptera
- Suborder: Polyphaga
- Superfamily: Bostrichoidea
- Family: Ptinidae
- Subfamily: Anobiinae
- Tribe: Stegobiini
- Genus: Stegobium
Pronunciation
How to pronounce Stegobium: //stɛˈɡoʊbiəm//
These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.
Images
Summary
The drugstore beetle (Stegobium paniceum) is a small, brown beetle with a wide range of food preferences, particularly in dried plant products, making it a prevalent pest globally. It has a complex life cycle, notable for its symbiotic relationship with yeast, contributing to its evolution and pest status.
Physical Characteristics
The drugstore beetle is a reddish-brown, small beetle ranging from about 1/10 to 1/7 inches (2.25 mm to 3.5 mm) long. It has an oval shape with a rounded head and dorsal plate that is bent forward. Adults possess serrated antennae ending in three enlarged, distinct segments, and their bodies are covered with rows of pits causing a striated appearance. The elytra have longitudinal grooves, distinguishing them from similar species.
Identification Tips
Adults can be identified by their 3-segmented clubbed antennae and the longitudinal grooves on their elytra. They are commonly confused with the cigarette beetle, which has serrated antennae and a smoother body.
Habitat
The drugstore beetle is cosmopolitan and thrives in warmer climates. It can infest a wide variety of dried plant products and is often found in homes, grocery stores, warehouses, and pharmaceutical facilities.
Distribution
Distributed worldwide, with higher prevalence in warmer climates.
Diet
The drugstore beetle feeds on a variety of food sources including bread, grains, spices, dried fruit, leather, hair, and museum specimens. It can also damage pharmaceutical products and medicinal plants.
Life Cycle
The life cycle transitions from egg to 4-6 larval instars, pupation in a silk and food material cocoon, and adult emergence. The female lays up to 75 eggs, which can take around 7–20 days to hatch. The entire cycle can be completed in as little as 40 days under optimal conditions.
Reproduction
Mating occurs via sex pheromones, specifically stegobinone, which females emit to attract males. The female's pheromone production peaks around the first day post-emergence and lasts for at least 14 days. Males and females engage in a physically interactive mating process involving their claws.
Ecosystem Role
As a pest, the drugstore beetle plays a role in degradation of stored materials, impacting both ecological and agricultural systems.
Economic Impact
Drugstore beetles cause significant economic loss by infesting and damaging a wide range of stored goods such as grains, cereals, spices, and medicinal products, leading to potential wastage and contamination of these items.
Health Concerns
The presence of drugstore beetles can lead to food contamination, health risks due to deteriorating stored products, and economic uncertainties associated with pest management in food facilities.
Evolution
Fossil evidence suggests that the genus Stegobium has ancient roots with known species dating back to the Late Cretaceous and Eocene periods. The evolution indicates a transition from wood-feeding ancestors to their current dietary preferences as pests of stored products.
Misconceptions
The drugstore beetle is often incorrectly referred to as the biscuit weevil, despite not being a weevil; it belongs to the family Ptinidae and has distinct physical features that differentiate it from true weevils.
Tags
- Coleoptera
- Pest
- Drugstore Beetle
- Stegobium paniceum
- Insect
- Stored Product Pest