Latin: Psocoptera
Psocoptera is commonly known as booklice, dust lice, bark lice or barflies. It is a small insect about a millimeter and really have nothing to do with lice. They do not suck blood and not near people in the same way as lice. They live primarily outside on trees or wooden fences. As such, they are not a nuisance to humans, but they can still cause irritation if they are near food stuff and along exterior walls.
Appearance
The dust lice are, as mentioned, small insects that are only 1-5 mm long. They can be with or without wings, as their color also variate from light to dark. The dust lice have long thin antennae at the front, which makes it easy to recognize them.
Biology and behavior
The dust lice can reproduce all year round, so they are not limited to a specific period or season. They can lay hundreds of eggs, which are laid under a web. Underneath this web the nymphs are hidden and kept safe from harm. A special fact about the dust lice and their reproduction is, that the eggs can develop without fertilization, which means that males do not have to be present.
The dust lice development from egg to adult, is through nymph stages. This means that the development does not change that much, as the first stages of the dust lice resembles the last stages of their life. The only thing that does change is their size and a bit their color. Once the dust lice have hatched, it has no or only small wings that it can use to “jump-fly” across the ground. It can therefore not really fly. It continues to look like the for the rest of its life.
Damage
The dust lice are also called both bark lice and book lice, those names are caused by the lice’s habitat. Outdoors, you can often find the dust lice in trees, and on woodwork and fences in the garden. They can also be found in damp books or paper.
You will often find the dust lice on damp exterior walls as they can not handle drying out. An advantage of having dust lice on damp walls is that they do eat and feed on the mold that can be found there. In newly built houses, where the walls are damp for a long time in the beginning, the dust lice will thrive. This can cause great irritation to the new homeowners.
You can find dust lice in food stuff, especially in starchy food like flour. They are not necessarily in the food, but on the edge or in the packaging. It is not hygienic having them that close to the food, and it can create great inconvenience and irritation.
Prevention and pest control
The dust lice are not dangerous or in any way harmful to your health. They can however crate a lot of irritation, if they are in your food stuff or just on the exterior walls in large quantities. There are several ways to both prevent and control dust lice from appearing in the home. In most cases, make sure that the home is neither damp, wet, or cold, as the dust lice will be attracted to cold and moist, as that is the best environment for them. Therefore, ventilate your home, and if there is a room where there is a problem with dust lice let the ventilation run. It can be difficult to get completely rid of them, since they will return, if the conditions become favorable to them again. If the reason for dust lice is molded walls, make sure to remove the moisture and mold completely, this can be done with an agent against mold, but this is not always enough in the long run.
"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)