Guide to Structural Pests

Guide to Structural Pests

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In the United States there are three main groups of termites: drywood termites, subterranean termites, and dampwood termites. The drywood and dampwood termites are not found in Maine and the subterranean termite is found only in the southern part of our state. The subterranean termites are by far the most damaging of the three types of termites. They have the longest life span of any household pest and can live, if conditions are favorable, up to 15 years. Termite infestations can be especially damaging because they often attack the important load bearing elements of a structure such as the sills, joists, studs, and girders. All termites live in colonies. Termite colonies are noncombative and it is possible for ants and termites to infest the same building. To exist, termites must live almost constantly in an environment of high relative humidity. A second critical need is a constant source of food such as wood or cellulose. Termites do not hibernate and continue to feed and be active throughout the winter. There are various methods of termite control that depend on construction type. The treatment for termites requires specialized skills and equipment and the use of state regulated pesticides. Once identified, the treatment for termites is best left to a licensed pest control specialist.

Carpenter ants are one of the largest ants we have in the United States. Carpenter ants live in colonies in wooded areas and do not cause problems until they forage into your home. Carpenter ants may cause cosmetic as well as structural damage if left untreated. These insects do not eat wood but hollow it out to produce galleries for nesting. They start their colony in decayed wood and expand to sound wood as the colony grows. Firewood stacked next to a building is an open invitation to carpenter ants. If you see a few large black ants crawling across your floor they are most likely foraging for food. Worker ants may wander as far as 300 feet from the colony in search of food. The nest could be located in the building or in a wooded lot alongside the building. Common nest sites include the dishwasher, under cabinets, around pipes, attics, leaky windows, leaky roofs, leaky doors, wall voids, and garage door jambs. You may be able to locate the nest by watching the ants and seeing where they go. Ants are either moving from their nest or to their nest. In three to five years, the colony may be large enough to produce winged swarmers. This is often the first indication that there is a colony in the structure. Successful treatment of carpenter ants depends on finding and treating the nest. It is important to treat the exterior of the building and the surrounding soil as well. Most products you may find in the store are baits that attract foraging and scout ants that feed on it and distribute it throughout the colony. This method, by itself, is often unsuccessful. Once identified, the treatment for carpenter ants is best left to a licensed pest control specialist.

The larvae of this family of beetles bore tunnels in wood, reducing it to very fine powder. When the insects leave the infested wood, they leave very fine holes called “shot holes”. The females lay their eggs in the exposed wood pores or cracks. They cannot lay their eggs in wood that has been waxed, painted, or varnished, unless it has been damaged. The larvae tunnel through the wood, following the grain of the wood, and pack the tunnels with a very fine powder-like frass. When the time to pupate approaches, they bore a pupal chamber close to the surface of the wood. This cycle can take from one to four years, depending on conditions. There are many different subspecies that have different times for development. Powder Post Beetle infestation is more likely to be in wood that is used for construction. Often it will not become evident that there is an infestation until years after construction when the mature beetles emerge. To solve an active infestation, you must stop the larvae. This is done using materials that penetrate wood. Once identified, the treatment for Powder Post Beetle infestation is best left to a licensed Pest Control Specialist.