General
The larvae of a number of beetle species can cause significant damage in wool fabrics, fur, mounted animals, hides and other products of animal origin. These involve the larvae of the common carpet beetle (Anthrenus verbasci Linnaeus), the Australian carpet beetle (Anthrenocerus australis Hope), the fur beetle (Attagenus pellio Linnaeus)
Naturally the larvae of these beetles are scavengers. They are often found in old, abandoned bird nests. In exceptional cases, vegetable substances serve as food as well. The adult insects (beetles) are often found on flowers in the summer, where they feed on pollen and honey. These insects are common in the Netherlands. Sometimes, a wandering beetle can be found by accident, which doesn’t mean that there is damage. The beetle may have looked for a place to stay during the winter for instance or accidentally have flown into the house during the spring or summer. In these cases it is not necessary to use insecticides.
Appearance
The larvae of the carpet beetle have golden brown hairs in general. At the abdomen, there are several bushes of longer hairs. The shape of the larvae is somewhat stocky and the first two species reach a length of 4-5 mm. The larvae of the fur beetle are often somewhat larger and can reach a length of 12 mm. The beetles of these three species have an oval shape and are 2-3 mm long. They are dull coloured and mainly in black and brown with some lighter frayed spots or bands here or there. The fur beetle is 4-5 mm long, dark brown to black with a white spot on the pronotum and middle of the elytra.
Development
Carpet beetles undergo a complete metamorphosis. This means that they subsequently go through the egg-larvae-pupate -imago (adult) stages. Depending on temperature and humidity, the egg stage lasts 6-35 days, the larvae stage may take 2-12 months. The pupate stage takes 5-19 days, whereas the beetle can stay alive 7-41 days after that.
Damage
Is only caused by the larvae. Considerable damage may be caused to woollen flooring, clothing and mounted animals.
Prevention
Prevent bird nests under roof tiles. Seal seams and cracks.
Control
For carpet beetle control, all hiding places where larvae are found must be treated with a residual-acting insecticide. At the sprayed locations, a residue toxic for insects is applied, which will retain its deadly effect on the insects for several months. For effective control, it is important for the resident to make all these places accessible to the exterminator of EWS. This includes plinths, seams and cracks under the edges of the flooring. In addition, it is recommended to vacuum thoroughly before the treatment, in particular in hard to reach places.
When the insects are found in a clothing cabinet or crate, one must remove the clothes so that the seams and cracks can be treated. Toys must be stowed away prior to the control measures. When treating cabinets, toys can be packed in plastic bags. After the treatment, you cant enter the house for two hours, and after that the house should be properly ventilated.
It is ill-advised to treat clothing with insecticides. Clothing and other fabric that has been affected should be cleaned (at least 30 minutes at 60°C will be fatal) and can then be repaired. In addition, insects in materials can be eliminated by storing them in a freezer for about 2 weeks (temperature lower than -10°C). A carpet beetle plague can be very resistant and it may be necessary to repeat the treatment after 8 weeks if insufficient result is obtained.