They're the overachievers of the insect world. Next to ants, termites are probably the natural world's most industrious insect. Living in colonies that can number a million members, termites have a caste system that allows for an efficient division of labor. They are steadfast in their life's mission--to consume wood and protect the colony at all costs. Termites are vital to nature because they recycle fallen trees back into the soil. Unfortunately, they can't tell the difference between a tree and a house.
No home is safe from termites. Homeowners become especially vulnerable as urban areas increasingly move into wild lands. Says Donna Kingwood of California's Structural Pest Control Board, "Termites are a fact of life. Anywhere there's wood there's potential for termite infestation." Termites are found in most states, but warm southern areas are most prone to attack. In California, $300 million to $400 million is spent annually to fight termites, most of that against the drywood species.
Of the 2,100 termite species--order Isoptera--41 are in North America. The kind most destructive to structures in this part of the world are the drywood and subterranean types. The drywood termite is more prevalent than the subterranean in Southern California's mild, dry climate, infesting buildings as well as furniture, utility poles and lumber piles. Both types are a problem in the San Fernando Valley, though the Valley is no more prone to termites than other areas of Los Angeles, said Steve Christensen of Western Exterminator Co.
A telltale sign that a house is being fumigated for drywood termites is the colorful tent enveloping the structure. This method is effective, but not without risks. The primary fumigant used, methyl bromide, has been blamed for 18 deaths in California in the last 13 years, including a woman who died in March after the building next to her Toluca Lake residence was fumigated. Most of the victims, though, were burglars or transients in the fumigated buildings.
Life Cycle of a Termite Colony
Termites live in highly organized colonies divided into castes, each performing a specific function. Termites aren't born into their castes. They take on roles depending on what's needed by the colony. Some entomologists believe that adult termites use hormones to somehow signal immature termites to develop into certain roles. Shown here is the typical life cycle of a termite colony.
Eggs: hatch om 50 to 60 days.
Larvae: Fed by adult workers, can develop into one of four castes.
Workers: Most numerous of the colony. They search for food enlarge the nest, build tunnels, clean and care for all other termites.
Soldiers: Blind, sterile and larger than workers, these termites develop powerful jaws and strong legs. Their job is to protect the colony from attackers such as ants.
Secondary reproductives: Capable of reproducing should the king or queen die.
Nymphs: Can become king or queen of new colony. Physically longer than other termites, they develop wings before they leave the nest to breed.
Swarmers: Mature nymphs who all leave the colony at the same time, usually in spring or fall. After finding a mate, they lose their wings. If they aren't eaten by predators, they start a colony in a new location.
King and queen: The actively reproducing termites of the colony. Their only function is to produce eggs. Queen is able to hold many thousands of eggs.
Signs of Termites
* Swarming of winged termites in late summer or fall; shed wings usually accumulate on windowsills.
* Evidence of tunneling in wood: blistering or thinning on wood surface.
* Pellets of partly digested wood excreted by termites under old furniture or near woodpiles.
Pest control experts recommend either whole-house or partial spot extermination for termites, after an inspection determines the extent of the infestation. The state Structural Pest Control Board warns that while fumigation may appear to be more costly ($600-$1,800 depending on house size), alternative methods may require many subsequent treatments if more termites are found.
Chemical fumigation: Chemical-absorbent materials are removed from home; building tented; Surrounding buildings may be evacuated. Fumigant is pumped in and allowed time to penetrate wood. Gas vented and tent is removed.
Heat treatment: Building tented. Non-heat-resistant removed; water left running to protect plastic pipes. Large propane heating unit connected to tent blows hot air in and around structure to heat walls. Heat is allowed to reach 120-130 degrees for 35 min. to one hour. Heat is shut off, tent removed.
Baits: Bait station containing slow-acting poison is placed into soil at intervals around building. Insects feed on bait and return to colony. Poison is passed on to other members, killing a portion of the exposed colony.