[Pest Profile] Old House Borer

OLD HOUSE BORER
Order/Family: Coleoptera/Cerambycidae
Scientific Name: Hylotrupes bajulus (Linnaeus) 

Description
Old house borer adults are large beetles, about 5/8- to 1-inch long. They are slightly flattened, brownish-black with gray or yellow-gray hairs. The first body segment behind the head has two raised, black, shiny knobs on the upper surface. Larvae are worm-like, creamy-white and up to 1¼-inch long when mature. The abdominal segments have deep folds between them so that the abdomen looks as if it is composed of a series of large beads.

Biology
Adults emerge in early summer to mate. Females lay 40 to 50 eggs in cracks or crevices of suitable wood. The hatched larvae bore into the wood and develop during the next two to 10 years with the majority taking from three to five years to reach the pupal stage. They emerge through oval holes that are 3/8 inch at their widest diameter.

Habits
Old house borers can infest old and new houses. Old house borer larvae feed only on coniferous lumber such as pine, spruce, fir and hemlock. The rasping and ticking of the larval feeding activity often is heard by building occupants and is one of the first signs of an infestation. Galleries are filled with fine frass mixed with small bun-shaped pellets.

Control
Old house borer infestations are discovered by hearing the larvae feeding in the wood, finding larvae in the wood, seeing the accumulating frass, discovering the emergence holes and seeing adult beetles. Determine if the infestation is active and then recommend treatment. Infested wood can be removed and replaced with treated wood. Reducing the wood moisture content to less than 10 percent slows the development of the larvae and often kills them. Galleries of existing infestations can be injected with aerosol or dust formulations. The surface of unpainted or otherwise unprotected wood can be treated and the galleries injected with disodium octaborate tetrahydrate. This kills exposed larvae and prevents reinfestation when the eggs hatch and immature larvae begin to penetrate the wood. Fumigation is the most effective way of controlling old house borer infestations, however, it offers no residual protection.