Like ladybugs, larder beetles belong to the order Coleoptera (beetles). They, too, have rigid protective wings, but at first sight they seem to be darker in colour. The colour pattern of the larder beetle is easy to recognize with its wide, light yellowish band across the first pair of wings. Black dots are also visible. The insect uses another pair of transparent wings when it flies, but these remain folded up and protected otherwise.
If they have not already invaded a house, larder beetles spend the winter hidden under a piece of bark. When the temperature becomes milder, they mate and the females visit flowers to feed on their protein-rich pollen. In early summer, larder beetles invade houses. The females lay their eggs on meat or on their food source. When they do not find any, they lay them in cracks near the larder or pantry. The typically hairy brownish larvae infest our food. Then they bury themselves in it or leave the source of food to find a place where they will be better protected during their metamorphosis. Once there, they transform into stationary nymphs and then into winged adults.
Places where they can be found in the home
Larder beetles prefer food containing fat or oil, as well as animal substances. Their larvae and hairy exuviate (skin that they shed during moulting) can be found on smoked meat (ham, bacon, sausage), cooked meat, dried fish and beef, cheese, animal meal, feathers, animal skins, mounted animals, dead or living insects, silkworm breeding facilities, dried tobacco and grain. The larvae are easier to detect when they leave the source of food and look for a place to undergo metamorphosis. They then choose hard materials that they do not feed upon, and even, dig holes in wooden beams or metal during heavy infestations. Several species of larder beetles can be found in the home. Some seek out animal skins or the cadavers of mice or squirrels stuck in the chimney. Others infest food products or grains in particular.
Install screens and keep doors closed to prevent adults from entering the house. You should also plug, seal or install finely-spaced gratings in holes around the house.
- Inspect wildflower bouquets before bringing them indoors.
- Inspect your home to ensure that there is no accumulation of dead flies.
- Keep your food in hermetically-sealed containers.
- Inspect dog and cat food.
- Remove the cooking grease that builds up behind the stove.
- Vacuum often since these insects also feed on fragments of dead skin and hair.
Check your insect and animal skull collections, stuffed animals, or “hunting trophies” regularly if you have any. Insect collections can be subjected to cold temperatures once a year to prevent them from being infested. Other people use paradichlorobenzene for this purpose.
The larder beetle plays a useful role outdoors where it acts as a decomposer, among other things, but it can cause significant damage in museums or houses and its presence should not be tolerated.
First make sure there are no bird nests, empty wasp nests, hives or animal cadavers (such as squirrels stuck in the chimney) nearby.
Once you found the source of the infestation, destroy it by freezing or burning the infested product before throwing it in the trash.
Larder beetles found on accumulations of dead flies can be removed with the vacuum.
Diatomaceous earth or other chemical products can be used as a last resort.
Not all insects with rigid wings are ladybugs. The order Coleoptera is the insect group with the greatest number of different species.
People who learn that their houses are infested with larder beetles often do not understand how insects could be there since they clean their homes regularly. However, it is easy for a small insect to find an opening that will allow it to enter a house. Furthermore, when it comes to solving the problem through housekeeping, people may feel ashamed or act incredulous, saying that they just cleaned the house. Instead, they should be looking for the source of the infestation. You should therefore be more vigilant; open boxes that are used infrequently or not at all to inspect stored items that do not need to be cleaned regularly. Prior to this day, our grandparents did what they called “spring cleaning” twice a year – fall as well as spring – a good habit that should be preserved to prevent heavy infestations.