Latin: Dermestes haemorrhoidalis
The Dermestes haemorrhoidalis has gradually become a frequent guest in many Danish homes. Especially in the larger cities. The Dermestes haemorrhoidalis is in the skin beetle family.
Appearance
The adult Dermestes haemorrhoidalis becomes about 7-9 millimeters long. Its body is almost boat-shaped, and the color is evenly black. On the underside of the body, however, the color is slightly different, as a series of small hairs gives the beetle an almost golden touch.
The Dermestes haemorrhoidalis larvae have a dark brown body. The underside of the larva is also lighter, and here it is also clear to see the subdivisions of the underside, from which brown bristles stick out. A Dermestes haemorrhoidalis larva can grow up to 15 millimeters long.
Biology and behavior
The Dermestes haemorrhoidalis share the same characteristics as the remaining members of the skin beetle family. They live on leftovers in nature, such as dead tissue. But the Dermestes haemorrhoidalis does not just eat the carrion. The dead animals are also used for the house Dermestes haemorrhoidalis egg laying, as the Dermestes haemorrhoidalis larvae can live off everything on the animal. Right from the soft flesh to the dry parts like cartilage, skin, and dry meat remnants.
When the larvae are fully grown, they typically leave the place where they have spent their first time. They seek refuge in a peaceful place where they can relax. In houses, it will often mean a space under the floors, which can create major problems. Because there is no natural cavity in this place, the larvae themselves will make sure to create it by gnawing passages in woodwork or packaging.
The larvae pupate in their passages, after which they are transformed into adult beetles. They develop best around 20 ° C, where the process lasts about a month. At colder temperatures or in the absence of food, the larvae can develop from egg to adult for several months. The Dermestes haemorrhoidalis can hatch all year round, but it is most often in the months of May-June that they appear, and where you can most often encounter the adult beetle.
Under laboratory conditions at 18-20 degrees, the adult beetles live for approx. five months and the female lays approx. 180 eggs distributed over the entire period.
The beetles are not rod-bound to a specific area. They are, on the other hand, highly active and are willingly walking or flying far from their original home. A Dermestes haemorrhoidalis that has hatched in the wild can therefore easily search in through a window in a house.
Damage
A Dermestes haemorrhoidalis can be quite practical when it is out in nature. If, on the other hand, the beetle enters the home, the enthusiasm is not so great. Here, the beetle will not only settle for the waste, but will just as well go for goods consisting of animal material such as animal feed or dried fish and meat. Fortunately, most meat products are stored in the refrigerator or freezer, where the beetle does not have access to, which is why they rarely do great damage.
On the other hand, there is little doubt if you have had a visit from Dermestes haemorrhoidalis larvae in the woodwork. The passages that the larvae gnaw appear as about two centimeters deep and circular passages that have a diameter of three to four millimeters. They can therefore cause great damage and even weaken the woodwork.
Prevention and pest control
A single beetle now and then hardly poses the big problem, as it is most often a single beetle that has strayed into the home. If, on the other hand, the beetles appear in large numbers, you should be cautious. It may be a sign that there is a source in the home.
As described, the beetle places its eggs in places where the larvae can feed on the material. This means that dead animals, dry food, or rubbish bins can often be the cause of the beetles’s appearance. In the house, the beetle will probably originate from a pigeon nest in the attic, dead mice or rats under the floor or a dead bird in the ventilation system. Be sure to remove and destroy the source, thoroughly clean the area around the site and treat it with an insect repellent or spray against creeping and crawling insects.
Larvae can also be found under the floors, and here they can be more difficult to get rid of. It can be a challenge to treat the area with pesticides. You should possibly repeat the treatment – and arm yourself with patience. If you want to prevent the Dermestes haemorrhoidalis, you should store items in which the larvae can develop in containers with tightly closed lids. Also pay attention to areas where food debris can be spilled. For instance, at livestock feed bowls or behind stoves or drawers.
"Pests in House and Home"
"Bed Bugs - Bites, Stings and Itches"
"Food Pests"
"Husets dyreliv" (Insects Around the House - Only danish)
"Skadedyr i træ" (Timber Pests - Only danish)
"Stuefluen" (Common Housefly - Only danish)