Royal Alberta Museum: Invertebrate Zoology - Bug Facts

[Caterpillars and Other Immature Insects]

Fact Sheets: Commonly Observed and Asked About Insects and Spiders Found in Alberta

Larder Beetle (Dermestes lardarius)

Larder Beetle
Photo CD 0023 3291 1601, Image #10 - Credit: Terry Thormin

Immature Larder Beetle
Credit: Terry Thormin

INTRODUCTION

This common pest beetle is a member of the family Dermestidae, which includes a number of pest species like the Carpet Beetle Anthrenus scrophulariae, and the Black Carpet Beetle Attagenus megatoma. The Larder Beetle is the most commonly encountered member of the family in Alberta.

IDENTIFICATION

This is a small beetle, about 6 to 10 mm long and rather oval in shape. It is dark brown with a broad pale brown or yellow band across the middle of the back, containing six small dark brown spots in the band. The larvae, which are often encountered, are rather tear-drop shaped, dark brown, and hairy, with several longer hairs at the pointed back end.

DISTRIBUTION

Found throughout Alberta and most of North America.

TIME OF YEAR

The larder beetle can be found indoors throughout the year. They are more commonly seen in the spring and early summer when adults from outside become active and fly into houses through open windows and doors.

HABITAT AND HABITS

Larder Beetle adults feed primarily on flower pollen. Larvae feed on a wide variety of animal byproducts, including hides, woollen products, feathers, meat like bacon, and dry pet food. This species is native to Alberta and is not uncommon outdoors. The problem arises when they invade houses and the larvae start feeding on carpets, clothing and food. When adult beetles come inside in the spring, they lay their eggs on any food or animal product that is available. When appropriate egg-laying locations are not available, they will lay their eggs around and under baseboards. Flies are often a problem, especially in older houses, and it is not uncommon to have many dead flies under baseboards and in spaces between walls, especially in the spring. Larder beetle larvae will feed on these flies when there is nothing else available.

SIMILAR SPECIES

The Black Carpet Beetle Attagenus megatoma is a smaller version of the Larder Beetle, but lacks the light band across the middle. The Carpet Beetle Anthrenus scrophulariae is the smallest of the three, at about 4 mm in length, is much rounder in shape and is black with white and red markings. The larvae of all three look quite similar.

COMMENTS

Most people are quite concerned when they discover they have one of these pests in their houses. Since the beetles most often turn up in the spring and early summer when they are flying, they are often not really a pest, and may actually be getting rid of dead flies. If you have them in stored food or they are damaging some animal byproduct then fumigation might be in order. Keep in mind that just putting all stored food in containers will often eliminate the problem. Check for damage to woollen and leather clothing and to stuffed animals before considering using poisons. If the problem persists throughout the winter you probably do have an infestation.

Note: We cannot provide advice on controlling insect pests. If you need more information beyond what has been provided here, we suggest you either search further on the web, or talk to a local exterminator.

[Royal Alberta Museum Home Page] [Invertebrate Zoology]

For more information on this bug, please contact the Bug Room.
© Copyright 2000-2008, Royal Alberta Museum - ALL RIGHTS RESERVED
Last update: August 29 2008