The Rhinotermitidae, called subterranean termites, is the most significant economic pest in the United States.
These termites cause a lot of damage annually to residences, historical buildings, and commercial structures.
Along with buildings, termites also consume books, documents, and pictures.
Subterranean termites have existed for over 55 million years and are particularly destructive.
Most of their success can be associated with their collective behavior, as the subterranean termites are naturally social insects.
This means that they live in social groups called colonies.
This insect is called a social insect because it has a specific role for every type of termite in the settlement to aid in the smooth running of affairs. It differentiates the insects from insects like the grasshopper, bugs, and mosquitoes, as most other insects work only for themselves.
For example, each bug will feed and reproduce itself individually.
In the termite colony, an entire group of termites is biologically designed to feed their parents and siblings, while another group is responsible for reproducing.
Because of the division of labor, the colony of termites runs as a single unit.
Classification
- Kingdom: Animalia
- Phylum: Arthropoda (Arthropods)
- Class: Insecta (Insects)
- Order: Blattodea (Cockroaches and Termites)
- Family: Rhinotermitidae
- Scientific name: Reticulitermes banyulensis
Colony Establishment
Usually, around the morning hours of the spring months, people may begin to see winged termites emerging in large numbers inside or from the soil outside their homes.
These termites are commonly referred to as subterranean termite swarmers.
Swarmers are new termite queens and kings leaving their parent’s colony so they can mate and create new colonies.
The swarmers pair up during this flight, then land and search for a place to start a family.
Their wings come off shortly after landing, and the new king and queen make their colony by exhuming a small chamber on a plot of soft soil.
Eventually, when the chamber is big enough, they crawl inside, seal the entrance, and mate.
From this point onwards, they spend the rest of their lives underground.
The queen lays her first batch, which can be around 6-12 eggs, within a few days or weeks of mating.
At this point, the king and queen tend to the young termites, but as the queen’s egg-laying capacity rises, the older offspring tend to their younger siblings.
The colony will now start to grow with the plentiful number of termites being reproduced every year.
The parental queen and king have the longest life span in the settlement.
They can survive for a decade or longer and form thousands of colonies.
The subterranean termite commonly found in the State of Virginia, in the USA, is the Eastern subterranean termite, also called the Reticulitermes flavipes, whose developed colonies of 6-7 years can contain over 60,000 workers.
These large subterranean termite colonies can often become acentric over time and distributed over multiple nesting sites connected by an intricate connection of underground channels.
Subterranean Termite Castes
Primary Reproduction
At specific times of the year, mature subterranean colonies produce large numbers of winged swarmers or “alates” that will ultimately become king and queen termites.
These young royals are dark-colored and are the only caste with active eyes.
The swarmers lose their wings after the flight, where they select a mate.
The new king termite remains substantially unchanged after losing his wings.
However, as the new queen commences egg production, her abdomen grows more substantial due to the formation of her ovaries.
When she stretches, the segments of her body pull farther apart, showing the white membranes between the sections of her abdomen, which gives the queen a striped appearance.
The eastern subterranean termite queen can stretch to about 14.5 mm in length.
She is an egg-laying machine, producing more than 500 offspring a year.
Secondary Reproductives
A termite colony is formed from a single pair of alate termites, the queen and king.
However, if the queen or king should die, other individuals within the colony will start to develop working reproductive organs to take their place.
These termites are called secondary reproductives. Secondary reproductives are light-colored but are more important than workers and would never grow wings.
In mature colonies, an auxiliary reproductive caste can be formed even when a producing queen is still present.
When this occurs, the secondary reproductive caste members will produce the predominant amount of eggs, making the colony grow faster.
Notwithstanding, no individual secondary reproductive can produce as many eggs as the queen; several hundred of them can exist in one colony, thereby creating thousands of eggs.
Secondary reproductives may also expand in ancillary nests where a group of workers has become isolated from the parent colony.
This new detachment and partitions of the nest extend the original colony’s scouring and pasturing territory.
Worker Caste
Subterranean termite workers are the caste found predominantly in infested wood.
The workers are in charge of all of the laborers in the colony. They care for the young, repair nests, build tunnels, locate sustenance, feed, and nurture the other castes and each other.
The most inexperienced termite workers perform domestic tasks inside the colony, such as feeding and caring for the young. In contrast, the older, more mature workers take on the high-risk jobs of foraging and nest building.
The termite workers’ caste can be either male or female, but they are usually sterile. They are milky white and have no eyes or wings.
Even though the mouth part of the termite worker is hard enough and used in gnawing and chewing on wood, they have a very soft body.
Soldier Caste
Subterranean termite soldiers act as the defenders of the colony.
They secure the settlement against ravaging ants and foreign termites.
When foraging tubes or passageways are broken, the soldiers gather around the crevice to guard against intruders.
Soldiers are synonymous with termite workers in that they are sightless, soft-bodied, and wingless.
Although the soldiers have an enlarged, sturdy, yellowish-brown head that has been designed for fighting.
The head has a pair of huge mandibles or jaws used to puncture, slice, and kill enemies, primarily ants.
However, the large mouthparts prevent the soldiers from feeding themselves, so they must rely on the workers for food.
Subterranean Termite Behavior
It is unknown precisely how subterranean termites find sources of food.
It is assumed that the termites divide the territory around the colony and start digging tunnels.
As they excavate, they come in contact with buried wood. Other termites are enrolled in the food source when food is found, while non-productive tunnels are closed off.
The foraging expanse of a single termite colony is almost impossible to foretell.
Lesser colonies may forage over a few yards if food is plentiful. Some larger colonies may forage over an extensive area the size of a football field.
The extent of their foraging range also depends on the season and weather; a settlement may not always feed over their entire range.
It has also been theorized that these assorted miniature-related colonies may cover a full foraging expanse rather than one vast territory.
Foraging termites secrete a variety of chemicals called pheromones that influence their behavior;
These chemicals are odors that communicate signals to other termites in the colony.
While tunneling underground, the foraging termites emit a trail of pheromones.
This pheromone is secreted from glands present in the abdomen.
The odor path is heightened when a food source is found to inform other termites of the feeding location.
Nevertheless, the intensity of the recruitment effort odor trail is influenced by earth temperature, moisture, and compression, as well as the quantity and quality of the food source.
Moisture Needs
Subterranean termites are always at risk of drying up; this is why the soil they live in must be able to hold water for an extended period to keep their territory moist.
When termites forage above ground for food, they must maintain a constant connection to the earth so that the workers and soldiers can occasionally return to rejuvenate their body moisture.
The mud tubes help the termites with this soil connection. If a cell becomes damaged, the worker termites will labor desperately to repair it.
If the compartments are beyond repair, the termites above the soil often die of dehydration.
However, subterranean termite colonies can be established above the soil; these above-ground infestations are found in structures with severe moisture problems.
Recurring moisture problems are usually the result of moisture absorption on a flat roof, leaking pipes within the structure, or ventilation problems in the vent.
The colony can survive above the soil for a long time in such circumstances.
Nutrition and Feeding
Though the subterranean termites can chew through and damage many materials, they can only get nourishment from cellulose.
However, subterranean termites cannot assimilate cellulose on their own.
To digest wood, these termites possess large numbers of microorganisms in their gut that convert the wood fiber into useful nutrients.
In the colony, most food is shared through trophallaxis, a mouth-to-mouth feeding process the subterranean termites use.
Foraging worker termites eat wood or other cellulose material directly and store the food in their gut.
They then return to the colony and feed the immature termites, soldiers, and reproductives.
Immature termites are outstanding in their nutritional necessities because, like all young insects, they must occasionally shed exoskeleton to grow.
When this happens, they also drop the lining of their hindgut, where the microorganisms that digest ingested wood live.
After discarding the coating, they are unable to digest food. To replenish their microbes supply, the young termites feed on fluids excreted from the hindgut of older termites, which contains this microorganism (This practice is called proctodeal feeding). Proctodeal nutrition is essential for the colony to survive.
Swarming Behavior
Swarming is the termite’s way of dispersing and creating subcolonies. Subterranean swarmers migrate from their parent colonies at certain times of the year when conditions are adequate.
Peak swarming season for the termites in Virginia starts from March to June.
The eastern subterranean termite usually swarms in the spring (March to May) during the daylight hours on warm days after rain.
Subterranean termite swarmers are drawn to light, so if they emerge either indoors or outside, this is an indication to homeowners of subterranean termite infestation.
Have you ever had to deal with termite infestation? Do you find this insect fascinating?
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