Termite – Field Guide to Common Texas Insects

Posted: June 17, 2018 at 6:40 am

Drywood termites (left)and subterranean termites (right), (Isoptera: Kalotermitidae). Photo by Drees.

Common name: TermiteScientific Name: VariesOrder: Isoptera

Description:Drywood termites are light yellow to black with clear to smoky gray wings, about 7/16 inch long. Worker termites (nymphs), and are up to 3/8 inch long, wingless, white to grayish with white to yellowish-brown heads, and soldiers are similar but with large rectangular darker heads bearing well developed jaws (mandibles) used to defend the colony.

Termites are occasionally confused with winged ants (Hymenoptera: Formicidae): termites have body segments that are similar in width, hair-like (filiform) antennae and, when present, four wings of equal length; ants have narrow waists, elbowed antennae and forewings that are longer than hind wings.

The differences between drywood termites (Kalotermitidae) and subterranean (Rhinotermitidae) are easiest to see in the venation of the wings of the adult reproductive caste. Wings of drywood termites have three heavy veins along the basal part of the front edge of the forewing and the crossveins near the wing tip are angled, making trapezoidal cells. Subterranean termite wings have just two major veins along the front edge of the forewing and the cross veins towards the wingtip are perpendicular to theseveins, making square and rectangular cells. Soldier and worker castes are more difficult to distinguish, but are generally larger than subterranean termites. However, other characteristics of infested wood can be used for identification.

Soldier termites and worker termites, Reticulitermes sp. (Isoptera: Rhinotermitidae). Photo by H. A. Turney.

Subterranean termites, Reticulitermes virginicus (in east Texas to Uvalde and Tom Green Counties) and R. hageni (in east Texas to Bexar and Eastland Counties), are social insects. There are three types (castes) of

termite adults in a colony; 1) reproductives; 2) workers; and 3) soldiers. Reproductives can be winged, primary reproductives called alates or swarmers or wingless, secondary reproductives. Winged reproductives have 1/4 to 3/8 inch long pale yellow-brown to black bodies and bear four wings of equal size that may be smoky gray to brown and have few wing veins. Termite workers are white and soft bodied. Soldiers resemble worker termites, except that they have enlarged brownish heads and strong, well-developed jaws. Soldiers defend the colony from invaders, primarily ants.

The Formosan termite, Coptotermes formosanus Shiraki, found primarily in the greater Houston-Galveston area and Beaumont-Port Arthur, is another subterranean species. It is larger than the

subterranean termite and has a pale yellow body color; the head shape of the soldier cast is more oval; and the wings of reproductives are hairy. Colonies, found in spaces such as wall voids or in hollows dug in wood both in or on the ground, are built of a mixture of chewed wood and soil cemented together, called carton. Reproductives swarm in late afternoon and evening, and are attracted to lights.

A termite queen, Reticulitermes sp. (Isoptera: Rhinotermitidae). Photo by Drees.

Life Cycle:Drywood termites: Simple metamorphosis. Winged male and female termites swarm and mate, usually in late summer and early fall. Males and females remain together to start a new colony and mate periodically thereafter to assure continued egg production. Eggs, produced by the mated female reproductive or queen, hatch in about two weeks.

Nymphs develop through two stages (instars) and become workers (nymphs). Additional molts produce adults including soldiers, winged forms called alates or primary reproductives, and wingless forms (dealates, secondary reproductives) which are capable of replacing deceased primary reproductives in an existing colony. A colony requires several years to become mature, an event marked by the production of winged reproductives. Mature colonies may contain up to 10,000 individuals.

Subterranean termites: Simple metamorphosis. Subterranean termites nest in the soil. Winged male and female reproductives swarm from the nest in daylight during the spring, usually after a rain when proper conditions (heat, temperature and light) occur. Male (king) and female (queen) termites mate and seek a colony site and stay together because periodic mating is required for continuous egg production. Development from egg to adult takes 2 to 7 weeks. Eggs, produced by the queen develop into wingless nymphs that develop through three stages (instars), requiring 10-14 days, 2-3 weeks and 3-4 weeks, respectively. At first, only worker termites are produced. Thereafter, there can be three types of nymphs: 1) false workers or pseudergates with no wing pads that molt continuously; 2) nymphs with wing pads that develop into winged male and female reproductives; and 3) soldier nymphs. Reproductive termites can develop from nymphs with wing pads (primary reproductives) as well as from false worker nymphs (secondary nymphoid repro- ductives or tertiary ergatoid reproductives) in the absence of primary reproductives due to the death of the queen or colony fractionation. A termite colony matures in 2 to 4 years and may contain 21,000 to 365,000 termites.

A winged reproductive termite, Reticulitermes sp. (Isoptera: Rhinotermitidae). Photo by J. Hamer.

Habitat, Food Source(s), Damage: Colonies of this social insect occur in sound, dry wood. Swarming occurs at dusk or early evening and the swarmers are attracted to lights. The mated pair starting a colony seeks a crack and crevice in wood, such as the spaces between wood shingles. The queen and male (king) produce and tend the first brood. Afterwards, worker termites care for the queen and male, tend the brood (eggs and immature forms), gather food, build and maintain the colony. Termite workers eat cellulose-containing materials found in plant products, which is digested by a one-celled animal (Protozoan) living in their digestive system. Workers share food with the other members of the colony. Tunnels or galleries which house the colony are produced by workers in dry, cured wood are clean and free of debris. Tunnels can run across the grain of the wood. Those reaching the woodsurface end in kick holes, where unique fecal pellets are expelled from the colony and pile up below infested timbers. These pellets are hard, 1/25 inch long, elongated seed-like particles with six lengthwise ridges between depressed surfaces. Soldier termites defend the colony from intruders.Subterranean termites: Worker termites gather food, maintain the nest, and feed and care forother members of the colony. Paper, cotton, burlap and other plant products as well as the stems of some plants (e.g. okra) serve as food sources. Workers returning to the colony share food with the rest of the colony. Workers feeding above ground construct tunnels or tubes made of soil and wood particles and salivary secretions. These tubes protect the workers and retain moisture in the nest.

Pest Status: Drywood termites: Termites occur in Texas coastal counties, with western spot infestations in Uvalde and San Antonio and north to Collin County, causing a great deal of concern to homeowners when discovered. Biology differs from the more common subterranean termite because it does not nest in the ground and thus requires a different, more expensive treatment approach. Termites are medically harmless.

Subterranean termites: Worker termites tunnel into structural timbers and other sources of cellulose on which they feed. Termites are harmless to man and animals although soldier termites can bite. They occur throughout Texas, but are more prevalent in coastal regions.

Management: See Subterranean Termites. See also How to Select a Termite Control Service and Household and Structural Pests.

For additional information, contact your local Texas A&M AgriLife Extension Service agent or search for other state Extension offices.

Literature: Drywood termites: Borror et al. 1989; Hamman and Gold 1992.Literature: Subterranean termites: Ebeling 1978; Hamman 1989; Haney 1993; Howell et al. 1987; Pawson 1995.

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Termite - Field Guide to Common Texas Insects

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