Just like the common furniture beetle (Anobium punctatum Degeer) this beetle species belongs to the Anobiidae family. The larvae preferably develop in oakwood. However, the development can also take place in other hardwood species, ans sometimes they are found in soft wood, when soft wood is processed in the immediate vicinity of affected hardwood.
The eggs are white, and have a diameter of about 0.6 mm. Because they are so small, they are hardly ever noticed. The larvae is yellowish white and can get 11 mm long. The beetle is dark brown to grey yellow and somewhat mottled. It is about 6 – 8 mm long. The beetle leaves the wood via an exit it gnaws itself. Often there are a lot of exits close together, making it look like a buckshot in the wood. The openings are round and about 2.5 – 4 mm in diameter. They are the first sign of the pest attack that can be observed.
Lifestyle and development
In April and May the beetles emerge from the wood. In heated buildings, this period can begin as early as January and proceed until June. It is assumed that some of the beetles mate in the wood after the females drop the eggs in the wood. The beetles make a loud tapping noise in and outside of the tunnels. This is what they owe their name ‘death watch beetle’ to. It was believed by some that, in a building in which this insect could be heard, someone would die soon. The development from egg to beetle lasts at least three years. The growth of the larvae depends on the presence of fungi that have settled in the wood. Mainly moist wood, which cause rot, is attacked by these insects. This can proceed to deep into the wood.
Control measures begin with reducing the moisture causes. For instance: resolving leakage, resounding walls, rising damp etc. In addition, it must be made sure that the ventilation is optimal. Under these circumstances, fungi will be unable to develop or sustain and the beetle will die after a while. However, since this can take several years, it is recommended to fight the beetle with an insecticide. Larger larvae can still survive in fairly dry wood (moisture level about 12*), although that will slow down their development.
Control of the large furniture beetle and its larvae can be done by spraying an insecticide permitted for the extermination of wood boring insects based on cyfluthrin, cypermethrin, deltamethrin or permethrin. Painted wood cannot be treated with these agents. If the wood has fungus, moisture reduction is essential. The fungi can be eliminated with fungicide based on azaconazole. Often, it is recommended to use a combined agent, that is both effective against the fungi and against the insects.
In order to use enough agent in the wood, the agents can also be injected into the wood in addition to being sprayed on the surface. Wood that still has to be processed to replace affected wood, must, preferably, haven been given a pretreatment in accordance with a professional wood preservation process with a permitted agent thereto.
For large objects and monumental buildings a hot air treatment can be considered. However, the costs thereof are significant.