Termite and (WDI)




This page is designed to give you a brief description of the most common Termite and (WDI) “wood destroying insects” in the north eastern part of the UNITED STATES. And to emphasize the importance of including a termite and wood boring insect inspection along with your home inspection.

Here at Top Notch Home Inspection we are well educated in the art of termite and wood boring insect inspections, and always include this inspection when preforming a home inspection. I have personally found ten’s of thousands of dollars in structural damages performing termite and wood boring insect inspections during a home inspection.

This damage would have gone undetected, and could have ended up costing our clients thousands of dollars in repairs. I have found that most owners are unaware that there is an existing problem with wood destroying insects. None the less they should be asked if they have any knowledge of an existing problem, and/or has the home ever been treated, and if so is there any documentation describing the treatment.


Subterranean termite colonies usually are located in the soil from which the workers build mud tubes to the structural wood where they feed. Subterranean termite colonies are always connected to the soil and/or close to a moisture source.

Termites digest cellulose in wood with the aid of special organisms within their digestive system. The workers prefer to feed on fungus-infected wood but readily feed on undamaged wood as well. The foraging workers feed immature workers, reproductives, and soldiers with food materials from their mouths and anuses.

A mature queen produces 5,000 to 10,000 eggs per year. An average colony consists of 60,000 to 250,000 individuals but colonies numbering in the millions are possible. A queen might live up to 30 years and workers as long as five years.

Subterranean termite colonies are established by winged reproductives which usually appear in the spring. Swarms usually occur in the morning after a warm rain. A male and female that have swarmed from an established colony lose their wings and seek a dark cavity inside which they mate and raise the first group of workers. Both of these reproductives feed on wood, tend the eggs, and build the initial nest.

After the workers mature, they take over expanding the colony and feeding the reproductives. As the colony becomes larger, light colored supplementary reproductives are produced to lay eggs which then become workers. The soldiers, which are also produced as the colony increases in size, are responsible for repelling invading ants and other predators.


The most significant damage to property within the UNITED STATES is caused by termites which readily feed on wood in structures and other cellulose containing materials. The National Pest Management Association (NPMA)  reports that termites attack 600,000 homes annually, causing more than $1.5 billion in damages.

Because the damage to structures is usually slow, it typically goes undetected for years so that the cumulative effects can be staggering. Eventually, the termites feeding activity can cause floors and ceilings to sag, walls to crack, and wood to become structurally unsound, resulting in the need for major structural repairs.


The adult winged female or queen loses her wings soon after mating with the smaller male and selects a secluded nesting site where she raises the first brood of workers. These workers are very small but assume the care of the larvae and the queen after they mature. Future workers are larger than those from the first brood because they receive better care. All workers are wingless.

Mature colonies range in-size from several thousand workers to 10-15,000 including satellite nest for C. pennsylvanicus, C. modoc colonies average 10-20,000 workers and up to 100,000. When raised at 90 degrees F, black carpenter ants complete their life cycle (egg to adult) in about 60 days. Swarmers do not appear in the colony for several years, usually three to four years for C.pennsylvanicus and six to ten for C. modoc. Swarming for these species occurs May through August and February through June, respectively.


 Carpenter ants are social insects that usually nest in wood. They commonly excavate galleries or tunnels in rotting or sound trees and, in structures, readily infest wood, foam insulation, and cavities. They prefer to excavate wood damaged by fungus and are often found in conjunction with moisture problems.

The workers excavate the nest, forage for food, and care for the young. Carpenter ants feed on sugar solutions from honey dew-producing insects such as aphids, sweets, and the juices of insects they capture. They do not eat the wood as they excavate their nest. They actively feed at night well after sunset continuing through the early morning hours. Foraging trails may extend up to 300 feet and, upon close inspection, can be seen on the ground as narrow worm paths.



Carpenter ants enter structures through gaps or cracks while foraging for food. However, the appearance of large numbers of winged adults inside a structure indicates that the nest(s) exist inside. The workers push wood shavings and pieces of foam insulation out of the nest through slit-like opening in the surface of the wood or other nesting site material. This material, which may contain fragments of other insects, and structural moisture problems are things to look for when trying to locate a colony in an infested structure. Rustling sounds in wall voids are another indication that there is a colony in the area.




 Powderpost beetles adults emerge in the spring from cells just below the surface of the infested wood. Soon afterward, mating occurs, and egg laying begins. The female lays 20-60 eggs in old emergence holes or cracks and crevices in the wood. Eggs hatch in six to ten days. The larvae feed for about one year before pupating for two to three weeks. The wood moisture content required for larval development is 13-30 percent. imagesbeetles.jpg

 When development is complete, the adult bores directly to the surface of the wood, emerging through a round hole 1/16 to 1/8 inch in diameter. Development under ideal conditions can be completed in one year; however, two to three years is more common. The adults are active at night and some species are attracted to light.

These beetles commonly infest seasoned sapwood of hardwoods and softwoods; they are rarely found in heartwood. They attack structure timbers, lumber, cabinets, and furniture. These beetles reinfest, and the females commonly lay eggs in wood from which they emerged. The larvae typically follow the grain of wood when feeding and fill their tunnels with wood frass. The frass is a fine powder with long pellets loosely packed into the imagesbettle2.jpggalleries.

Reference material: Pest control technology, Technician’s Handbook 3rd edition.