The earliest definite fossil (Figure 1) of a termite dates back to the Early Cretaceous period, which was approximately 146 to 100 million years ago. (Wimbeldon, 2013) Fossil evidence shows that termites were quite diverse during the Cretaceous period, which suggests that they would have emerged prior to this period, possibly sometime in the Jurassic, or approximately 201.3 to 146 million years ago.
The name "Termite" groups together 12 different families of organisms, which all fall under the Order Blattodea. Until recently, termites were considered to be a part of the order Isoptera, along with ants. The visual similarities between these two different groups are apparent, however small differences in structures such as the antennae and wings (Figure 2) are what distinguish the two groups from one another. (Marin Termite Control, 2013) Instead of being related to an ant, a termite is considered to be a highly modified, wood-eating cockroach.
The name "Termite" groups together 12 different families of organisms, which all fall under the Order Blattodea. Until recently, termites were considered to be a part of the order Isoptera, along with ants. The visual similarities between these two different groups are apparent, however small differences in structures such as the antennae and wings (Figure 2) are what distinguish the two groups from one another. (Marin Termite Control, 2013) Instead of being related to an ant, a termite is considered to be a highly modified, wood-eating cockroach.
Termites are distributed widely around the world and are most abundant in numbers and species in tropical rainforests. They are found as far as British Columbia on the North American continent, and occur naturally in the Mediterranean. Termites thrive in humid environments such as those found in Southern Africa, Australia and New Zealand. (Attenborough, 1990) Many species have been accidentally introduced by humans into habitats where they do not naturally occur, making the distribution of termites vast. Generally, the species of termites found in areas such as the Mediterranean are different to the ones that occur in areas such as Australia and Africa, and this is why there are differentiations in behaviour, such as they way the nests are built. (Attenborough, 1990)
A termite's life cycle (Figure 3) is heavily embedded in the eusocial system of its colony. Upon fertilisation by the king of the queen, eggs are produced and are laid in the royal chamber of the nest. The king and queen termites of the colony are responsible for all reproduction in the colony. For this reason, the queen's body is morphed into what is like an egg making factory, which can produce up to thirty thousand eggs per day! (LSU, 2013) The eggs are then carried by worker termites and placed in a nursery chamber, where they will hatch into pale white larvae (nymphs). Over the course of several moults, these larvae (nymphs) grow and assume their role in one of the following castes in the termite eusocial system:
1. Worker: responsible for constructing the tunnels and chambers of the nest and feeding and looking after other termite castes. Generally live for one to two years.
2. Soldier: useful in combat, but their enlarged heads and mandibles render it impossible for eating. Generally live for one to two years.
3. Reproductive Alate: responsible for mating with the queen. Born with wings. The queen also falls into this category, and can live more than a decade. (LSU, 2013)
Research suggests that the allocation of a termite to a specific caste is due to the needs and requirements of the colony. Termites may also develop into another caste if the colony requires it, indicating that the caste system is not 'set in stone.' (LSU, 2013)
A termite's life cycle (Figure 3) is heavily embedded in the eusocial system of its colony. Upon fertilisation by the king of the queen, eggs are produced and are laid in the royal chamber of the nest. The king and queen termites of the colony are responsible for all reproduction in the colony. For this reason, the queen's body is morphed into what is like an egg making factory, which can produce up to thirty thousand eggs per day! (LSU, 2013) The eggs are then carried by worker termites and placed in a nursery chamber, where they will hatch into pale white larvae (nymphs). Over the course of several moults, these larvae (nymphs) grow and assume their role in one of the following castes in the termite eusocial system:
1. Worker: responsible for constructing the tunnels and chambers of the nest and feeding and looking after other termite castes. Generally live for one to two years.
2. Soldier: useful in combat, but their enlarged heads and mandibles render it impossible for eating. Generally live for one to two years.
3. Reproductive Alate: responsible for mating with the queen. Born with wings. The queen also falls into this category, and can live more than a decade. (LSU, 2013)
Research suggests that the allocation of a termite to a specific caste is due to the needs and requirements of the colony. Termites may also develop into another caste if the colony requires it, indicating that the caste system is not 'set in stone.' (LSU, 2013)
The evolution of the eusocial and caste system within termites is much different to that of other eusocial insects such as ants or bees. According to Barbara Thorne of the University of Maryland, "evolution of eusociality in termites likely occurred in small families in which most helpers retained developmental flexibility and reproductive options." (Thorne, 1997) A set of ecological and life-history traits of termites and their ancestors may have predisposed them towards eusociality. Associate professor Sassan Asgari of the University of Queensland stated that in order to be classified as eusocial, the colony must posses the following traits:
1. Co-operative care of developing embryos and larvae
2. Sterile individuals performing physical labour, while fertile individuals reproduce
3. Overlap of two or more generations (Asgari, 2013)
Since termite colonies posses all these qualities, it is safe to say that termites live and operate within a eusocial system of castes. As with any society, the colony must have somewhere to live - and that is where the complex, brilliant and often enormous termite mounds come into play.
1. Co-operative care of developing embryos and larvae
2. Sterile individuals performing physical labour, while fertile individuals reproduce
3. Overlap of two or more generations (Asgari, 2013)
Since termite colonies posses all these qualities, it is safe to say that termites live and operate within a eusocial system of castes. As with any society, the colony must have somewhere to live - and that is where the complex, brilliant and often enormous termite mounds come into play.
Image credits
Figure 1:
Wimbeldon, B. 2011. The Berriasian Age: 164 to 140 million years ago.
Figure 2:
Marin Termite Control. 2013. Fumigation vs. Local Treatment.
Figure 3:
LSU AgCenter. 2013. Biology and Life Cycle: Colony Members and Life Cycle.
Figure 1:
Wimbeldon, B. 2011. The Berriasian Age: 164 to 140 million years ago.
Figure 2:
Marin Termite Control. 2013. Fumigation vs. Local Treatment.
Figure 3:
LSU AgCenter. 2013. Biology and Life Cycle: Colony Members and Life Cycle.