**Larder Beetles** (*Dermestes lardarius*) are common cosmopolitan pests of **dried animal products** (skin, hair, feathers, meat, and leather), as well as stored dry foods. They are often found in homes, warehouses, and museums. The primary damage is caused by the larvae, which feed on a wide variety of protein-rich materials, often infesting pet food, preserved meats, dried cheeses, or taxidermy specimens. They are also a nuisance pest when the mature larvae bore into wood, plastic, or foam to create a pupation chamber.
Taxonomy and Classification
Larder Beetles belong to the order Coleoptera, family Dermestidae (skin beetles), sharing the family with carpet beetles and Khapra beetles. They undergo complete metamorphosis. These insects are highly efficient decomposers in nature, cleaning up carrion, but become pests when they move indoors to feed on stored products or animal remains (like dead rodents in wall voids or pantry goods).
Physical Description
Adult Larder Beetles are dark brown or black, 1/4 to 3/8 inch long.
- **Appearance (Key ID):** They are easily recognized by a distinct, pale yellow or yellowish-white band running across the back (elytra), which contains three black spots.
- **Larvae (Key ID):** Hairy, dark brown, and segmented, up to 1/2 inch long. They are covered in long, reddish-brown hairs and possess two distinct, horn-like spines (urogomphi) on the posterior end.
- **Damage Sign:** Small holes in dried food/animal products, presence of shed larval skins, and the movement of mature larvae boring into structural materials near the food source.
Distribution and Habitat
Larder Beetles are cosmopolitan (found globally). Their habitat includes structures that house food or animal products: pantries, pet food storage areas, mills, rendering plants, and wall voids where a dead animal (mouse, bird) may have died and dried out.
Behavior and Conflict
The conflict is food contamination and minor structural damage.
- **Food Contamination:** They consume and contaminate dry, protein-rich foods, including pet food (especially dried kibble), dried meats, and museum specimens.
- **Pupation Boring:** Mature larvae leave the food source and often bore into surrounding soft materials (wood molding, insulation, cork, or foam) to create a safe place to pupate. This can cause minor, but visible, damage to wooden structures.
- **Source Seeking:** Finding the primary source of infestation (e.g., a dead animal in a hidden cavity) is critical for effective eradication.
Management and Prevention
Control requires aggressive sanitation and source removal.
- **Find the Source:** The first step is to locate and remove the primary food source (infested pantry items or the remains of a dead animal).
- Thoroughly clean all infested areas, using a vacuum to remove all larvae and shed skins from cracks and crevices.
- Store all susceptible dried foods (including pet food) in sealed, hard-plastic or glass containers.
- Spot treatments of residual insecticides may be used on cracks and crevices near confirmed infestations, but sanitation is the main defense.
Conservation and Research
Larder Beetles are managed as stored product and sanitation pests. Research focuses on improving detection methods in commercial food handling facilities and the development of new, target-specific pest control materials.