drywood termites


Termites are insects that go through incomplete metamorphosis, i.e., egg, larva, nymph, adult. The caste system (king, queen, soldier, worker) of termites is essential to their colony development. An understanding of termite biology, ecology and the complex (pheromone-based) communication system of these insects can help termite control personnel design the most effective targeted control program for treating termites.

Termites efficiently eat wood and wood products via a symbiotic relationship between termites and gut microbes (i.e., bacteria and flagellates). Without these microbes, termites would not be able to survive, hence the manipulation of this symbiotic relationship may be a potential method of control.

Termites are commonly found in forested environments and, when forested areas are disturbed by development (e.g., creation of a subdivision), termite colonies may be suppressed for a period of time before reestablishing. Different termite species colonize areas (urban, suburban, rural) at different rates and this should be considered when developing a monitoring and control plan.


There are approximately 3,000 termite species in the world and about 80 of these species are considered pests of economic significance. Subterranean termites represent about half of the pest species, followed by drywood termites. Dampwood termites can also be considered pests, but do not cause significant economic damage compared to subterranean and drywood termite species. A 2010 estimate showed that the global economic impact of termites is approximately $40 billion per year, with subterranean termites accounting for 80 percent of these costs (Rust and Su 2012).

Subterranean termites can impact residential or other structures by entering through cracks in the foundation structure or building shelter tubes to reach internal wooden structures. Drywood termites generally invade wood structures via the winged reproductive (alate) stage of development.


Pest management professionals can install plastic monitoring stations in the ground at 10- to – 20-feet intervals around residences (according to manufacturer’s instructions) in order to detect and monitor termite populations. This practice follows the principles of integrated pest management, i.e., surveillance-based targeted control. The availability of more monitoring stations increases the chance that termites will be detected. Placement of the monitoring stations and type of bait is dependent on the surrounding environment (competing food sources) and expected termite species. The monitoring stations should be placed in areas expected to have termite activity (tree stumps near residence, near areas of existing termite damage, along foundation) to maximize detection. Untreated pieces of wood (bait) are inserted into the monitoring stations, and pest control professionals regularly (once or twice per month) check the wood for termite damage and presence.

If termites are found at a residence, untreated pieces of wood can be replaced with baits (e.g., insect growth inhibitors) that will allow recruitment of the termites in a colony to help spread the bait throughout the colony, hence increasing the mortality rate. Baits must be weather resistant, have no repellant qualities and should be slow-acting in order for a small number of affected termites to spread the bait to the rest of the colony.

Once control is accomplished, pieces of untreated wood bait can be returned to the monitoring stations for further surveillance. Regular surveillance and monitoring of these stations is important for a successful result. In areas with heavy termite infestations, area-wide monitoring and treatment (at multiple residences) may be required for long-term control.


Chemical- and/or pressure-treated termite-resistant wood can be used to construct new homes or home additions. There are also siding materials (e.g., concrete-fiber) used on structures that are considered termite resistant. Some woods (e.g., redwood, mahogany) are naturally resistant to termites, but may lose these resistant properties with age. While using products that resist termites may deter termites from damaging the products, termites can still attack/damage other cellulose-based materials within structures.

If installed properly, metal shields and/or concrete-filled blocks can be used to help deter termites from invading a residence through the foundation. During their winged reproductive stage, drywood termites invade through cracks and other openings, hence, sealing entry points can deter establishment of these termites, i.e., cover vents, small cracks, joints. Ensuring that wood is kept free of moisture and preventing soil exposure to wood can help impede colonization of subterranean termites.

Regardless of the preventative techniques employed, professional termite inspections, monitoring and targeted control may still be necessary as no termite-resistant product is guaranteed to prevent an infestation in perpetuity.


Termites are pests that are difficult to control and require professional assistance. Termite control professionals are trained to detect and control termite issues in residential and other structures. It is essential that the type and extent of structural termite infestation is evaluated by a pest management professional prior to initiating treatment as this assessment can inform treatment decisions.

Reference: Rust MK, Su NY (2012) Managing social insects of urban importance. Annu. Rev. Entomol. 57:355-75.