Controlling termites

Gerald J. Lenhard, Louiana State Univ
Bugwood.orgWhile Subterranean and agricultural termites are commonly found throughout the Western and Southern U.S, and Drywood termites are mainly in Western and Coastal Southern states, they aren’t limited to only those areas. 

“With shipping and transportation today, they are probably everywhere,” says Roger Gold, professor and endowed chair in the department of Entomology at Texas A&M University.

There are two types of termites that are most common in lawns: Subterranean (Rhinotermitidae) or agricultural (Termitidae). Both termite types have “workers” that cause the damage, and “soldiers” that defended the colony. The reproductive castes are known as “queen” and “kings” and swarm during the spring and summer months.

A third type of termite is known as Drywood and essentially lives in the plants themselves, like in trees where they eat wood. Subterranean and agricultural termites live in the soil, where they tunnel through and attack cellulose either on the roots of plants, or above ground. 

The agricultural termites prefer to eat decomposing grasses, but in times of drought, they will attack growing ground covers.


Identification
Subterranean termites will have mud tubes the size of a small pencil that they use to protect themselves when they emerge from the ground. These tubes are diagnostic of subterraneans.

A drywood termite can be identified in the solider caste by having teeth on the mandibles. “The mandibles are out in front of the face on the termites and they are used for the defense of the colony. The worker caste also has mandibles, but they are very small compared to the soldier,” Gold says. There are also characteristics on the soldier’s head or the wings of the swarmers that give it away.

“The soldiers of subterranean termites have smooth mandibles, while both agricultural and drywood termites have at least one prominent tooth on the mandible,” Gold says.
Drywood and subterranean termites can be, and often times are, misidentified as ants. “After termites swarm, they quickly lose their wings, and have the general appearance of ants,” Gold says.

However they are broadly jointed between the thorax and the abdomen, while ants have a narrow segment known as a pedicle.


Treatment
Gold says, generally, it is not economically justified to attempt to control agricultural termites, as the cost of control exceeds the value of the grass or twigs the termites eat.
These specific termites do not eat trees or bushes, and feed primarily on dead grass and small pieces of wood around shrubs or bushes. 

“As far as lawns go, the damage from agricultural termites usually become apparent when the lawn or pasture is stressed and is drying or thinning out,” he says.
Normally, lawn care operators would irrigate lawns, and a growing turf can outgrow the damage caused by these specific termites.

“If subterranean or drywood termites are destroying a tree, then control would be justified,” Gold says.

Look for products that contain the active ingredients imidacloprid, fipronil or bifenthrin.

Always read pesticide label directions, Gold says, because the site or pest must be on the label to legally use the product.

The author is an associate editor at Lawn & Landscape. He can be reached at bhorn@gie.net