Pests in Gardens and Landscapes: Quick Tips
Subterranean termite workers and a soldier (big head).
Adults (left) and soldiers (right) of three common species of termites:
dampwood (largest), drywood (middle size) and subterranean (smallest).
Winged adult subterranean termite.
Termites are among the pests most feared by homeowners. Observing swarms of flying termites does not always mean your home or building is infested. A professional inspection of the structure is usually required to confirm an infestation. If you suspect your home is infested, call a professional. Regular inspections every 3 to 5 years help detect infestations before they become damaging. Do-it-yourself pesticides for use against termites are generally not effective.
Common termites in California
Management of each termite species is different.
- Subterranean: build nests in soil and infest wood that is in contact with soil or access wood via earthen shelter tubes.
- Dampwood: nest in very moist wood and soil and are most often found in cool, humid areas along the coast.
- Drywood: nest above ground in relatively dry wood such as lumber, utility poles, fences, and dead limbs on trees.
Distinguish winged termites from flying ants.
- Check the antennae, wings, and waist to confirm that pest insects are termites and not ants.
Maintain your building to keep termites out.
- Keep a 12-inch barrier of smooth concrete, coarse sand, or other inorganic material between the soil surface and structural wood beneath a building.
- Choose termite-resistant wood or use concrete footers for fences or structures that must contact soil.
- Remove wood piles, untreated fence posts, and buried scrap wood near structures.
- Provide ventilation to substructures and keep them dry.
- Immediately repair foundation cracks, plumbing leaks, faulty grades, and exterior defects in structural wood.
- Properly finish exterior wood using sealants or paint.
If termites invade your home:
- Destroy any shelter tubes that subterranean termites have built between soil and wood structures.
- Remove infested wood and eliminate excess moisture.
- For any suspected or confirmed infestation, contact a professional for help. Pesticides and specialized devices and techniques available only to licensed pest control operators are usually needed to control structural infestations.
Termite control methods
- Most of the proven effective methods in California are for professional use only, so it’s best to hire a professional.
- Careful inspection is needed to detect and contain termite damage and colonies in order to make best use of localized treatments, especially for drywood termites.
- Nonchemical tactics such as wood replacement, heat, electrocution, and the use of desiccants should be considered before pesticides. These may be especially useful against drywood termites.
- Barrier applications of insecticides may be made around structural perimeters by professional applicators through trenching, drilling or rodding. Examples include pyrethroids, as well as insecticides such as fipronil, chlorantraniliprole, and imidacloprid.
- Injections of insecticidal liquids, dusts, or foams may be made directly to drywood termite galleries or sometimes to shelter tubes of subterranean termites. Desiccants, oils, pyrethroids, neonicotinoids, fipronil, and many other active ingredients may be used.
- Whole-structure fumigation with sulfuryl fluoride may sometimes be necessary when drywood termite infestation and damage are widespread.
- Bait station systems can be effective in some cases, but may take several months or even years to control the problem and must be followed up with constant monitoring.
Minimize the use of pesticides that pollute our waterways. Use nonchemical alternatives or less toxic pesticide products whenever possible. Read product labels carefully and follow instructions on proper use, storage, and disposal.