Old House Borer
Old House Borers attack softwoods only, coniferous woods such as pine, fir, spruce and hemlock. It usually attacks stored lumber, after which it is introduced into homes as they are built. Log homes infested with Old House Borers is a very common occurrence. This beetle is of importance since it will re-infest a structure.
Old House Borer Identification
The Old House Borer belongs to the beetle family Cerambycidae, a group also known as the Long Horned Beetles. The key identifying characteristic of this family is long, thin antenna that are often as long or longer than the body of the beetle. The adult Old House Borer can be from 3/8 of an inch to 1 inch in length with the males typically being smaller than their female counterparts. The beetle’s body has a slightly flattened appearance. Its color is usually brownish black to black. The prothorax or the area behind the head is rounded in shape and contains two raised, shiny, black bumps. The wing covers of the Old House Borer are black, with lighter gray colored areas forming bands that are usually present about one half way down the wing covers.
Old House Borer Larvae
The head of the Old House Borer larvae is round and much larger than its tail, a shape which is typical of the Cerambycidae Beetles, which are known as Round Headed Borers. This larvae is grayish white in color and grows from 3/4 inch to 1 5/8 of an inch in length. The head capsule is dark brown, and three simple eyes are found on each side of the head when viewed from the front. This characteristic sets the Old House Borer apart from other Long Horned Beetle larvae found infesting wood. Other Long Horned Beetle larva have only one such eye on each side of the head. The sound of the mature larva feeding inside timbers can sometimes be heard as a clicking sound much like fingernails clicking together. Exit holes and frass are the signs that point to an actual infestation. The frass of the Old House Borer consists of very fine powder and tiny pellets that are tightly packed within the galleries. The holes of the larvae are oval-shaped. This oval exit hole and the appearance of frass are usually the first indications of an Old House Borer infestation. Larvae feed until they reach about 200 mg in weight. At this time, the mature larva tunnels to the surface of the wood and cuts an oval-shaped exit hole. This exit hole is then sealed with packed frass. Just below this exit hole is a pupil chamber where the larva pupate. The oval exit hole created by the emerging adult can be one fourth of an inch to 3/8 of an inch in diameter. The adults mate and live only about 10 days for females and 15 days for males.
Control measures depend on the extent of the infestation, and where the infested wood is located.