Structure, Types, Life Cycle and Control of Termites: In-depth Guide
TERMITES (Macrotermes bellicosus)
Phylum: Arthropoda
Class: Insecta
Termites are social insects commonly known "white ants".
Social Insects
Social insects are groups of insects which live together in a colony where there is division of labor among members or castes. Other social insects are ants, honey bees and wasps.
Features Common to Social Insects
Termite Habitat
Termites need a source of moisture to survive. In temperate habitats, they are found in decaying woods, and in the soils. Termites are found in dark, damp areas whereby they are not exposed to sunlight.
Structure (Characteristic Features) of Termites
A typical colony contains workers, soldiers, and reproductives. Their body is divided into three parts head, thorax and abdomen. The head bears a pair of short antennae and mouth parts. The thorax bears three pair of walking legs.
Characteristics of Worker Termites
They are smallest and the most numerous of the castes.
They are made up of male and female termites, with no sex organs, no eyes and no wings.
They have brown head with chewing mouthparts and a pair of antennae.
Function of Worker Termites
1. provide food for the colony and nurse the nymph
2. dig tunnels
3. build and repair the nest
4. groom the queen
Characteristics of Soldier Termites
Soldier termites are yellow brown in color. They have a large head with powerful jaws/mandibles.
They are blind, wingless, and sexually immature. The thorax bears three pairs of walking legs.
There are two types of soldiers:
1. Mandibulate soldier: have large hardened head with powerful jaws.
2. Nasute soldier: have round head that protrudes out to form a sharp point.
Functions of Soldier Termites
They defend the colony against invaders. The mandibulate soldier used the head to block narrow tunnels and snaps with their strong jaws against intrusion of ant. The nasute soldier produce a poisonous sticky substance to entrap their enemies.
Reproductive Termites
(The winged or "alate" castes)
They have reproductive organs, eyes, two pair of wings, and 3 pairs of legs.
The wings break off after nuptial flight and remain wingless. Two reproductive termites become king and queen. The queen later becomes largest member with king being the second larger. The mature queen has an enormous white abdomen with clear spiracles on the sides.
Functions of Queen and King
1. The queen duty is solely eggs laying
2. The king mates with the queen to fertilize the eggs
Structure of Termite Mound or Nest (Termitarium)
Termites are renowned for their ability to construct intricate mounds or nests, known as termitaria. These structures serve as both a habitat and a protective environment for the colony, facilitating essential activities such as foraging, reproduction, and temperature regulation. The design and complexity of termite mounds vary widely among species, with Macrotermes bellicosus being one of the species known for building some of the most impressive and complex mounds.
1. External Features of Termite Mound
a. Shape and Size
- Variety in Design: Termite mounds can vary greatly in shape and size, depending on the species and environmental conditions. Some mounds are conical or dome-shaped, while others are more irregular or tower-like.
- Height and Diameter: The size of the mound can range from small, inconspicuous structures to towering formations that can reach several meters in height and width. For instance, the mounds of Macrotermes bellicosus can exceed 6 meters in height.
b. Material Composition
- Soil and Saliva: The construction material primarily consists of soil particles bound together with termite saliva. This mixture creates a durable, cement-like substance that hardens and strengthens the mound.
- Organic Matter: In addition to soil, termites incorporate organic matter such as plant debris into the mound structure, enhancing its stability and insulation properties.
2. Internal Structure of Termite Mound
a. Chambers and Galleries
- Nursery Chambers: The innermost chambers of the termitarium serve as nurseries where the queen lays eggs and the young are reared. These chambers are carefully controlled in terms of temperature and humidity.
- Storage Chambers: These chambers are used to store food, such as partially digested wood or fungi cultivated by the termites. The stored food is essential for feeding the colony, especially during dry or unfavorable conditions.
- Royal Chamber: The royal chamber houses the queen and king, providing them with protection and an optimal environment for reproduction. This chamber is usually centrally located and heavily guarded by worker and soldier termites.
b. Ventilation System
- Passive Ventilation: Many termite mounds have a sophisticated ventilation system that helps regulate the internal temperature and humidity. The mound's design often includes porous walls and a network of tunnels that allow air to circulate. Hot air rises through the central chimney, while cooler air is drawn in from the lower parts of the mound.
- Active Ventilation: Some termite species actively manage their nest's environment by blocking or opening specific tunnels to control airflow. This system helps maintain a stable environment, crucial for the survival of the colony and the growth of fungi cultivated by certain termite species.
c. Moisture Regulation
- Water Collection and Storage: Termites need moisture to survive and often incorporate features in their mounds to collect and store water. Some species build their nests in locations that allow access to groundwater, while others use the nest's structure to capture dew and rainwater.
- Humidity Control: The structure and composition of the mound help maintain a stable humidity level, essential for the termites and the fungi they cultivate. The mound's insulation properties and internal design work together to prevent excessive moisture loss or gain.
3. Function and Adaptation of Termite Mound
a. Protection
- Defense Against Predators: The termitarium provides a physical barrier against predators, such as ants and other insects. The hard, durable outer layer and complex internal design make it difficult for intruders to penetrate.
- Thermal Insulation: The structure of the mound protects the colony from extreme temperatures, maintaining a relatively constant internal climate despite external fluctuations.
b. Social Organization and Division of Labor
- Efficient Space Utilization: The design of the termitarium facilitates the division of labor within the colony. Different areas of the nest are designated for specific activities, such as rearing young, storing food, or defending the nest.
- Communication and Coordination: The network of tunnels and chambers allows for efficient communication and coordination among colony members. Pheromone trails laid by the termites help guide individuals to specific areas within the mound.
Mode of Life of Termites
Nutrition in Termites
Termites eat cellulose in its various forms as plant fiber. Cellulose is a rich energy source, but remains difficult to digest. Termites rely primarily upon symbiotic protozoa such as Trichonympha in their guts to digest the cellulose. This process of digestion only takes place in the worker. The food is then regurgitated to feed other members of the castes.
Termites also practice fungi-culture. They cultivate fungal gardens that grow on plant matters, providing a nutritious mycelium on which the colony then feeds.
Life Cycle of Termite
Early in the rainy season, mature reproductive termites leave and swarm. They emerge in their numbers from the parent nest and fly off to establish new colonies. This flight is term as “nuptial flight” or “colonizing flights”. During the nuptial flight they rip off their wings and become the king or queen termites of a new colony.
Termites show incomplete metamorphosis. The queen lays fertilized eggs which hatch into pale, white larvae. They grow into one of the three colony castes: workers, soldiers and reproductive termites.
For further reading on termite biology and life cycles, visit the University of Florida Entomology and Nematology Department.
Economic Importance of Termites
Termites, often considered pests, have a significant economic impact on various sectors, including agriculture, forestry, and urban infrastructure. Their activities can lead to substantial economic losses and, in some cases, provide ecological and economic benefits. Understanding the economic importance of termites involves examining both their destructive and beneficial roles.
1. Destructive Economic Impact
a. Damage to Structures
- Residential and Commercial Buildings: Termites are notorious for their ability to feed on wood and other cellulose-based materials. In regions where termites are prevalent, they can cause severe structural damage to homes, office buildings, and other structures. The cost of repairing termite damage and implementing control measures can be substantial.
- Historical and Cultural Sites: Termites can also damage historical buildings and cultural heritage sites, leading to costly restoration and preservation efforts.
b. Agricultural Losses
- Crop Damage: Termites can damage crops by feeding on roots, stems, and other plant parts. In particular, subterranean termites can harm crops such as sugarcane, maize, and rice, leading to reduced yields and economic losses for farmers.
- Plantation and Orchard Damage: In plantation agriculture, termites can damage trees like rubber, coconut, and oil palm. This can reduce the productivity and lifespan of these trees, affecting the profitability of plantations.
Learn more about agricultural impacts at FAO's Plant Production and Protection Division.
c. Forestry and Timber Industry
- Deforestation and Forest Degradation: Termites contribute to the breakdown of dead trees and other plant material, which is beneficial for nutrient cycling. However, they can also attack living trees, leading to forest degradation and economic losses in the forestry sector.
- Timber Damage: The timber industry suffers from termite infestations, as these pests can significantly degrade the quality of harvested wood, making it unsuitable for construction or other purposes..
d. Costs of Control and Prevention
- Pest Control Expenditures: Homeowners, businesses, and governments spend billions of dollars annually on termite prevention and control measures, including inspections, treatments, and repairs. These costs can be particularly high in regions with a high risk of termite infestations.
Explore termite control methods at the National Pest Management Association.
2. Beneficial Economic and Ecological Roles
a. Nutrient Cycling and Soil Formation
- Decomposition: Termites play a crucial role in decomposing dead plant material, breaking down cellulose, and recycling nutrients back into the soil. This process enriches the soil and promotes plant growth, which is essential for maintaining healthy ecosystems.
- Soil Aeration: By tunneling through the soil, termites improve soil structure and aeration, which can enhance water infiltration and root growth.
For further reading on the ecological roles of termites, visit the Smithsonian Institution.
b. Biological Indicators and Research
- Biodiversity Indicators: Termite populations can serve as indicators of biodiversity and ecosystem health. Studying termite species diversity and abundance can provide insights into the condition of habitats and the impacts of environmental changes.
- Scientific Research: Termites are studied for their unique digestive systems and social structures, providing valuable information for scientific research. For example, understanding termite digestion could lead to advances in biofuel production and waste decomposition technologies.
Learn more about research on termites at the International Union for the Study of Social Insects.
c. Economic Potential in Biotechnology
- Enzyme Production: The enzymes produced by termites for cellulose digestion have potential applications in various industries, including biofuel production, paper and pulp processing, and waste management.
For more on termite biotechnology applications, visit Biomass Magazine.
Control of Termites (Macrotermes bellicosus)
1. Preventive Measures
a. Structural Barriers
- Physical Barriers: Implementing physical barriers during construction, such as stainless steel mesh or termite shields, can prevent termites from accessing buildings.
- Chemical Barriers: Applying soil treatments with termiticides around foundations creates a chemical barrier that deters termites.
For comprehensive guidelines on termite prevention, refer to the USDA Forest Service.
b. Building Design
- Moisture Control: Termites are attracted to moisture. Ensuring proper drainage, repairing leaks, and maintaining ventilation can reduce the risk of infestation.
- Material Choices: Using termite-resistant materials, such as treated wood, metal, or concrete, can help prevent termite damage.
2. Biological Control
a. Nematodes
- Description: Beneficial nematodes are microscopic worms that can parasitize termites.
- Application: Nematodes can be introduced into termite-infested areas, where they infect and kill termites.
b. Fungal Pathogens
- Description: Certain fungi, such as Metarhizium anisopliae, are pathogenic to termites.
- Application: These fungi can be used in biocontrol strategies, infecting and killing termite colonies.
Learn more about biological control at the Biological Control Research Group.
3. Chemical Control
a. Baiting Systems
- Description: Termite baits are placed around the perimeter of a building. The bait contains a slow-acting toxicant that termites take back to the colony, effectively eradicating it.
- Implementation: Regular monitoring and maintenance of bait stations are crucial for long-term effectiveness.
b. Liquid Termiticides
- Description: Liquid termiticides can be applied to soil, wood, or other structures to create a chemical barrier against termites.
- Safety Considerations: It is essential to follow safety guidelines and environmental regulations when using chemical treatments.
For information on safe and effective chemical treatments, visit the National Pesticide Information Center.
4. Integrated Pest Management (IPM)
a. Monitoring and Detection
- Regular Inspections: Conducting regular inspections helps in early detection of termite activity.
- Use of Technology: Employing tools like moisture meters, acoustic detection devices, and thermal imaging can improve detection accuracy.
b. Combining Methods
- Integrated Approach: Combining physical, biological, and chemical control methods, along with preventive measures, provides a comprehensive and sustainable solution to termite management.
For more on IPM strategies, visit the IPM Institute of North America.
A daptive Features of Termites
1. Queen has large or swollen abdomen; which stores eggs.
2. Soldier (Mandibulate) has massive/large mandibles, large head to defend the colony or use of large head to block entrance of tunnel.
3. Worker termites have well developed mouthparts and legs; to carry out feeding, building nest and repairing the nest and collecting food for the colony.
Conclusion
The structure, life cycle, and control of Macrotermes bellicosus are critical areas of study for preventing and managing termite infestations. These termites, with their complex social structures and destructive feeding habits, pose a significant threat to buildings and agricultural areas. By understanding their biology and implementing a combination of preventive, biological, and chemical control methods, it is possible to manage and mitigate the damage caused by these pests effectively.
For further reading and resources on termite control, visit the USDA's Agricultural Research Service.
