Termites, as a group, are the major wood destroying pests in Nevada. More time, money and effort are spent on their control than on all other wood destroying pests combined. The arid land subterranean termite is found statewide while the Western Subterranean termite is found primarily in northwestern Nevada. The life cycle, damage and appearance of each are so similar as to be indistinguishable. For practical purposes they will be considered simply subterranean termites.
There are basically three castes which comprise a subterranean termite colony: reproductives, soldiers and workers/nymphs. Reproductives are categorized as primary reproductive, secondary reproductive, queen and king. The primary reproductive (Figure 1) is a winged adult called an alate. It is dark-brown to brownish-black with brownish-gray wings. The body length is about 1/3 inch with wings. The secondary reproductive (Figure 2) is white, about 1/5 inch long and lacks wings. The queen (Figure 3) is without wings and with an abdomen that is enlarged so that it has a striated appearance. The king (Figure 4) is also wingless but does not have enlarged abdomen. The worker and soldier (Figure 5) are white, lack wings and are about one half inch long. Both the worker and soldier are blind. Winged primary reproductive termites are often mistaken for winged ants.
|Figure 1||Figure 2||Figure 3||Figure 4||Figure 5|
Winged primary reproductive termites are often mistaken for winged ants. The following illustration shows the difference between the two winged insects.
A colony of subterranean termites may range from three thousand individuals to several thousand individuals depending on conditions such as age and location. Each colony normally has one queen and one king. Subterranean termites are normally ground-dwelling organisms which live in chambers and tunnels in the soil, or live in contact with soil. One of the characteristic signs of subterranean termites is the "shelter tube" which the colonies build from the soil to a structure, also referred to as a "mud tube." These tubes are built from sand or soil or small particles of wood or both, which are coated with a glue-like substance that is secreted by the termites. Two types of feeding habits are found in the subterranean termites. The first is the feeding on sound or decaying wood or other cellulose materials. The second is feeding on a diet prepared by other members of the colony.
Methods of control are directed primarily toward prevention of an infestation. This can be done by:
- Mechanical alteration which consists of adding barriers of an impenetrable material, remove cellulose debris, removing moisture, insuring sufficient ventilation, removing faulty grade and breaking earth to wood contacts.
Pesticide treatments that:
- Soil under and adjacent to a structure to create a barrier.
- Foundation to get pesticides into any cracks in the foundation footing which lead to the outside soil.
- Wood to make it impervious or resistant to termites.
In those instances where the structure has become infested, control is directed toward pesticide treatment of the soil and wood, and/or replacement of infested wood. Western Drywood Termites is the native to southern Nevada and it is not known to have become established in Northern Nevada.
Carpenter Ants - There are 12 species of carpenter ants in Nevada of which 8 are of economic importance. The life cycles, damage, etc of carpenter ants are similar so as to be indistinguishable except for the size and color of each. For practical purposes they will be considered as a single entity. Carpenter Ants have complete metamorphosis (i.e. egg, larva, pupa, adult). The white egg is smaller than the head of a pin and either oval or sausage shaped. The larvae are white, grub-like, without legs and have very small heads. The pupa develops in a white to brown, parchment like cocoon. Adult carpenter ants have three castes: queen, male and worker. These castes have the common appearance of all ants. A winged queen may reach from 1/16 inch to 2/5 inch in length depending on whether or not they are “major”, “intermediate” or “minor”. The color of adults ranges from amber through red through reddish brown or black. The wings are formed on both males and females that swarm. When crushed these ants emit a strong formic acid odor. They do not sting but will bite and sometimes inject formic acid into the wound. Carpenter ants do not use wood for food but rather for nesting. They excavate galleries in wood which resemble termite galleries but can be distinguished by the fact they are entirely clean, contain no debris and have almost “finished” appearance. The sawdust carried out of the nest indicates where the nest is located. Usually the nests are found in moist, unsound or partially decayed wood but can be found in sound wood. Carpenter ants feed on both plant and animal material. Items found in the kitchen such as syrup, honey, jelly, sugar, meat, grease and fat are particularly attractive. They contaminate food and are a nuisance with their movement inside and outside of buildings. However, their primary damage is done in their excavation of wood. The ants have shown some preference for moist rotting wood around foundations but readily attack support timbers, joists, studs, etc. Their excavation of galleries and tunnels weaken the wood in structure thus making it unsound.
There are two primary methods of control for Carpenter Ants. The first is prevention and involves:
- Elimination of structural defects, primarily sealing all cracks and crevices.
- Removal of all cellulose debris and excessive moisture, and insuring sufficient ventilation.
- Screening all openings, especially ventilation openings, with a 20 mesh non corrodible metal screen.
- Using chemically treated lumber.
The second is elimination of an infestation and involves:
- The replacement of all infested or damaged wood.
- Injection or placement of pesticides in infested wood.
Velvety tree ant (Liometopim luctousum) is a glistening ant about 2.5 to 6.0mm long with a velvety black abdomen, red thorax and brownish black head. It occurs in large colonies in crotches or hollows of trees and stumps. Within homes velvety tree ant invasions may occur where a limb touches the house. In picnic areas it crawls over food and bites, ejecting a poison into the wound. When crushed a disagreeable odor is produced. In homes nest can occur in joints or cracks in wood. The velvety tree ant excavates the wood to create and expand a nest chamber: it does not bore into wood. Pieces of sawdust carried out of the nest indicate where the nest is located. Velvety tree ant trails may extend 200 feet from a house.
Last Updated (Tuesday, 15 June 2010 20:55)