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Look For Termites - July 9, 2008
Jeff Schalau, Associate Agent, Agriculture & Natural Resources
University of Arizona Cooperative Extension, Yavapai County
Termites belong to the order Isoptera (iso-ptera = equal-winged), which refers to the adults which have two pairs of equal length wings. There are 17 species of termites that occur in Arizona, but only 7 species are considered to be economically important pests. Scientists have placed these species into three broad categories based on their habitat: subterranean, damp-wood, and dry-wood.
Subterranean termites derive their name from the fact that they must be in contact with soil as a source of moisture. For these termites to move into a wood source above ground, they construct “mud” tubes made of soil, soft fecal matter and wood chips. Subterranean termites are the most common termite pest in Arizona and their presence is easily observed.
Damp-wood termites are found in sound dead wood that is moist. These termites nest in soil and come to wood for food, but are not considered economic pests. Dry-wood termites are capable of infesting dry wood that is not in contact with the ground. Because they do not construct earthen mud tubes, infestations are more difficult to detect. A sign of dry-wood termite infestation is the presence of hard, dry fecal pellets that resemble fine sawdust.
Information about termite biology and identification is available on-line and in Cooperative Extension offices. Termite identification, biology, and management information is also available at the following web sites: University of Arizona Urban Integrated Pest Management (IPM) website at ag.arizona.edu/urbanipm/ and the University of California IPM Website at www.ipm.ucdavis.edu.
Termites can cause damage to wood and compromise structural integrity. The first step in successful pest management is correct identification of the pest. The next step is to gain and understanding of that particular species’ biology and habitat requirements. In addition, effective termite management can require some knowledge of building construction. For most people, it is advisable to hire a reputable, professional pest control company to carry out your inspection and control program.
Prevention is also an important termite management strategy. This can be accomplished through proper building design and using termite resistant construction materials in the appropriate areas. Some recommendations follow.
Recent research has proved the effectiveness of foundation sand barriers for subterranean termite control. Sand with particle sizes in the range of 10 to 16 mesh is used to replace soil around the foundation of a building and sometimes in the crawl space. Subterranean termites are unable to construct their tunnels through the sand and therefore cannot invade wooden structures resting on the foundation. Stainless steel screening may also be available soon as a physical barrier for subterranean termites.
- Keep all substructural wood at least 12 inches above the soil beneath the building.
- Stucco siding that reaches the ground is attractive to termites.
- Keep attic and foundation areas well ventilated and dry.
- Use screening over attic vents and seal other openings, such as knotholes and cracks, to discourage the entry of winged drywood termites.
- Inspect utility and service boxes attached to the building to see that they are sealed and do not provide shelter or a point of entry for termites.
- Reduce chances of infestation by removing or protecting any wood in contact with the soil.
- Look for and remove tree stumps, stored lumber, untreated fence posts, and buried scrap wood near the structure that may attract termites.
- Keep landscaping and irrigation water well away from the foundation of the structure.
- Consult your local city building codes before beginning repairs or modifications.
In the past, chlorinated hydrocarbon insecticides (e.g., chlordane) and organophosphates (chlorpyrifos) were extensively used for termite control but many of these materials have been phased out because of health and environmental concerns. Termiticides currently available are not as persistent, but they are safer for humans, non-target organisms, and the environment. Again, it is recommended that these insecticides be applied by licensed professionals.
The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at email@example.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://cals.arizona.edu/yavapai/anr/hort/byg/.