LARDER BEETLE
Common Name: Larder Beetle
Scientific Name: Dermestes lardarius
Introduction. The common name of larder comes from the fact that this is a major pest of cured meats and other stored provisions. It is found worldwide.
Recognition. Adult larder beetles measure 1/4 to 3/8 inch long and are elongate oval in shape. They are dark brown to black with a pale yellow to beige transverse band on the elytra (hardened front wings or wing covers) which contains 6 to 8 small black spots.
The larvae are 3/8 to 5/8 inch long, dark brown, and are covered with long brown hairs (setae). The larvae have 3 pairs of short legs and have a pair of small spines urogomphi that curve backward from the top rear portion of the body.
Similar Beetles. Other similar desmestid beetles (e.g., hide beetle and black larder beetle) lack a pale transverse band at base of elytra (wing covers).
Damage and Signs of Infestation. Infested animal skins or hides are damaged primarily on their inner surface with holes chewed by the larvae to reach the desired feeding sites. To pupate, mature larvae bore into solid materials such as hams and wood. They may bore into wood to a depth of about 1/2 inch. The width of the hole is about 1/8 inch and the last larval molt skin is used to plug the entrance hole.
Biology. Adult female larder beetles lay their eggs on suitable larval food or in cracks and crevices where such food is stored. The number of eggs may range from 102 to 800 and they hatch in about 12 days. Male larvae molt 5 times and female larvae molt 6 times but there may be more molts under adverse conditions. The mature larva wanders to find a suitable place for pupation, which lasts 3-15 days.
Developmental time (egg to adult) may require only 40 to 50 days but usually takes 2 to 3 months or longer. There is usually only 1 generation per year but in some localities there may be as many as 6. The adults may overwinter in bark crevices and enter buildings in the spring and summer. Adults live about 3 to 5 months.
Habits. Larder beetle adults and larvae feed on all kinds of animal products such as dried fish, ham, bacon, meats, cheese, dried pet food, and dried museum specimens including insects, hides feathers, horn and hair. Only occasionally do they attack materials of plant origin such as stored tobacco.
Most damage is done by larval feeding, but adults also feed and cause damage. The mature larvae wander in search of solid material in which to pupate. They bore into such material to make a pupal chamber and then plug the entrance/exit hole with the last molt skin.
The primary breeding areas are the (1) pantry and where dried pet food is kept. Other places may include: (2) wall/ceiling voids where mice, yellowjackets, and honey bees nested and died or where cluster flies, face flies, leaffooted bugs, boxedler bugs, and lady beetles overwintered and died, (3) rodent bait left in attics, crawl spaces, or basements; (4) wasp and hornet nests and remains in attics and under eaves; (5) bird nests and poultry houses, (6) catch trays of insect light traps, (7) animal trophies or rugs, (8) stored items made of leather or fur, and (9) dead animals in the chimney flue. In such places the larvae and adults feed on available animal material.
Adults avoid light when mating and during egg laying.
Cultural Control & Preventative Measures. The key to controlling larder beetles is o find the primary source(s) or infestation and eliminate it/them. Besides the obvious pantry items, dried pet food, and animal trophies and furs, it may be necessary to check for the more less obvious unusual food items and places such as listed above. Take into consideration both current and past problems with cluster flies or lady beetles in the winter, or rodents and birds nesting in the building.
A thorough inspection should be followed by good sanitation practices. Infested items should be removed and professionally treated (if valuable) or discarded. A vacuum cleaner fitted with a hose attachment is useful for removing accessible beetles, larvae, larval molt skins (exuvia), frass and fragments of damaged items.
Professional Control. A Rottler pest management professional will assist in locating hide beetle breeding sources and making recommendations for preventing re-infestation. Dead animals / carcasses will be removed, if accessible. A spot treatment of an infested structural void using a residual insecticide dust or a crack and crevice treatment into cabinet and shelf corner seams / junctures using non-residual or residual insecticide aerosol formulations may be applied by the technician to stop additional pest breeding.
Locations
Serving the St. Louis Metropolitan area since 1956, including
Arnold, Ballwin, Chesterfield, Crestwood, Creve Coeur, Des Peres,
Fenton, Florissant, Kirkwood, Maryland Heights, Overland, St.
Charles, Webster Groves, Wentzville and surrounding areas.
In Illinois: Belleville, Collinsville, Edwardsville, Columbia,
Madison, Waterloo, O’Fallon, Granite City, Alton, St. Clair, Monroe
and surrounding areas.
Columbia & Jefferson City, MO and surrounding areas.
