Dermestes lardarius (Linnaeus, 1758)

Larder beetle

A 7-9 mm beetle with a pale yellow band across its back that raids pet food, cured meats, and the dead flies in your attic.

Order: Coleoptera
Family: Dermestidae
Group: Fabric & structural beetles
Ontario status: Established, common in Ontario homes, especially where pet food, cured meats, or dead insects accumulate

Why it matters

A frequent Ontario pantry pest via pet food, and the classic 'attic beetle', most infestations trace to dead insects in voids, not to the kitchen at all.

Origin

Eurasian; followed cured meats and stored protein around the world, lardarius means 'of bacon.'

Behavior

Adults and larvae both feed. Larvae are hairy and wander before pupating, sometimes boring into wood or insulation to make a pupal chamber, which alarms homeowners unnecessarily.

Living conditions

High-protein dry foods: pet food, cured meats, cheese, dried fish. Also, and commonly in Ontario, the accumulations of dead cluster flies, wasps, and lady beetles in attics and wall voids.

Signs of presence

Dark beetles (7-9 mm) with a pale yellowish band, in pantries or near pet food
Hairy larvae wandering on walls (seeking pupation sites)
Damage to dry pet food, jerky, or cheese

Weaknesses

Depends on protein accumulations, remove the pet food spill or the dead insects and it leaves
Larvae wandering to pupate are conspicuous and easy to track back to the source
Killed by freezing

Myths and facts

Myth The larvae boring into wood means they're eating my house.
Reality They bore pupation chambers, not food tunnels, the wood damage is cosmetic and the beetle leaves. The real food was the dead flies in the attic.

Research notes

Morphology

Adult 7-9 mm, dark brown to black with a broad pale yellow band across the basal third of the elytra (often with dark spots within the band). Underside pale. Larva hairy, up to ~12 mm, brown with pale bands.

Diagnostics

The pale elytral band is diagnostic among Ontario dermestids. Larval wandering behavior plus banded adults confirms.

Easily confused with

Hide beetle, Dermestes maculatus Hide beetle lacks the pale elytral band and has white hairs on the underside of the abdomen tip; larder beetle has the band.

Life cycle

Adult: Live several months; feed and reproduce
Egg: Laid on protein food; hatch in ~1 week at warm temperatures
Egg to adult: 2-3 months in warmth
Generations per year: 2-3 indoors
Nymph or larva: Larvae feed 1-2 months, then wander and bore pupal chambers

Development

Complete metamorphosis; larvae bore pupal chambers into wood, cork, or insulation.

Reproduction

Females lay ~200 eggs on protein substrates.

Distribution

Global: Cosmopolitan
Native range: Eurasia
Ontario: Established; homes, pet-food storage, attics provincewide

Ecology

Carrion and stored-protein scavenger; the attic-cluster-fly association is the dominant Ontario reservoir. Pupation boring is a shelter behavior, not feeding.

Resistance

Unknown, no significant documented resistance.

IPM implications

Find the protein, not the beetle: inspect pet-food storage, then attics and wall voids for dead-insect accumulations. Removing the reservoir (including old cluster-fly carcasses) ends the infestation; the wandering larvae are the map to the source.

Chemical ecology

Carrion and protein-degradation volatiles guide oviposition; defensive chemistry unremarkable.

Genetics and DNA

No reference genome published as of 2026.

Taxonomy

Order Coleoptera, family Dermestidae. Genus Dermestes; lardarius = 'of bacon/lard.'

Open questions

Quantifying the attic-carcass reservoir's contribution to household infestations.

References

Hinton, H.E. (1945). A Monograph of the Beetles Associated with Stored Products, Vol. 1. British Museum (Natural History).