Reticulitermes flavipes, the eastern subterranean termite is the most common termite found in North America.^[1] These termites are the most economically important wood destroying insects in the United States and are classified as pests.^[1] They feed on cellulose material such as the structural wood in buildings, wooden fixtures, paper, books and cotton. A mature colony can range from 20,000 workers to as high as 5 million workers and the queen of the colony lays 5,000 to 10,000 eggs per year to add to this total.^[1]

Distribution

The eastern subterranean termite is the most widely distributed termite found in the eastern United States. R. flavipes is commonly found in Southern Ontario, and is found in all the eastern states including Texas.^[2]

Other termites found there are the dark southeastern subterranean termite (Reticulitermes virginicus) and the light southereastern subterranean termite (Reticulitermes hageni). These are less important economically (such as in damage to crops) because of their more limited range.^[3]

Description

Eastern subterranean termites, like other social insects, share resources and divide labor based on a caste system.^[1] They live in loosely associated societies called colonies which are composed of both males and females. The termites in the colony are generally organized into the worker caste, the soldier caste, and the reproductive caste.^[1]

Worker caste

Workers are about 1/8 inch long and are blind, wingless, soft-bodied, creamy white to grayish-white with a round head. They make up the majority of the termites that actually eat the wood. They are sterile and forage for food and water, construct and repair shelter tubes, feed and groom other termites, care for eggs and young, and participate in colony defense.^[3]

Soldier caste

Soldier termites are also wingless and resemble workers except that they have a large, rectangular, yellowish-brown head with long black mandibles. The soldiers’ primary function is colony defense ^[1] and the mandibles are mainly used for crushing enemy ants which may invade the colony. Additionally, R. flavipes has a fontanelle (frontal gland pore) on the forehead which releases a sticky latex to ensnare enemy ants.^[2] The soldier caste only makes up 1 to 2% of the entire colony. The soldiers are not capable of feeding themselves and rely on the worker termites to provide them with regurgitated food.^[1]

Reproductive caste

These are the adult winged termites who have two pairs of long narrow wings of equal size, dark skin, and beaded antennae.^[1] A nuptial flight takes place, mating occurs and they shed their wings. They are black and about one centimeter long, with grayish transparent wings. Neotenic reproductives are potential kings and queens of the colony, available as replacements if needed. They are generally yellow or mottled black and the abdomen of the female may be distended with developing eggs.^[3]

Life cycle

R. flavipes are opportunistic, and a newly hatched termite can develop into any of a number of castes. At first, it becomes a worker termite and is most likely to remain one for its entire lifespan. Molting can change the worker into a pre-soldier and subsequently, a soldier. The soldier caste is a terminal stage which can no longer molt.^[3]

R. flavipes also molts into nymphs, which are the precursors of winged adult termites called alates which are sexually mature. Nymphal termites are non terminal and can revert back to the worker stage. These reverted nymphs are called pseudergates. Nymphs and workers can also develop into secondary and tertiary neotenic reproductives respectively.^[3]

Behavior

Because termites are social insects, they share a lot of their tasks. This can be seen through the caste system, where different castes take on different responsibilities for the good of the whole colony. R. flavipes cooperate in the rearing of young and also share their resources with the nest.^[3]

Swarming is the sudden, dramatic appearance of R. flavipes alates in the daytime from February to April. After this behavior male and female alates lose their wings, pair up, and form new colonies.^[3]

R. flavipes is mobile throughout its life and no permanent central nest area exists. Therefore all termite castes can be found in any of the different sites occupied by a colony. Their activity is determined by food, moisture and temperature, and movement is usually driven by one of these necessities. Termites feed on anything made of or containing cellulose, but can tunnel into non-cellulose containing material to gain access to their destination. This behavior can be destructive to human activities.^[3]

Human impact

Along with Reticulitermes virginica, R. flavipes is responsible for 80% of the $2.2 billion spent annually in the United States on termite control.^[4] Termites feed on wood cellulose, meaning that their presence in human made structures often goes unnoticed for lengthy periods of time. A termite infested timber will appear structurally sound from the outside, while inside it will have a honeycombed appearance. To detect the presence of R. flavipes the observer can test the integrity of the wood by tapping it with a screwdriver. If present, R. flavipes is found at, near or below ground level. Trim work, sub flooring, flooring, and the structural timbers are the areas of a building most susceptible to termite damage. The Eastern subterranean termite is considered a serious economic timber pest and it is estimated that in high activity areas more than 1 in 5 homes have been or will be attacked.^[2]

Termite control methods include: physical barriers, chemical treatments, and physical treatments (such as heat, freezing, electrocution and microwave irradiation).^[5]

Structural damage to buildings is not R. flavipes’ only impact on humans. Termites also play a critical role in the decomposition of organic matter in natural communities. Without termites, the accumulation of dead organic matter on the forest floor would become detrimental to integrity of that forest. The benefits provided by R. flavipes in terms of their contribution to environmental regulation may far outweigh the disadvantages they pose.

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