Termites
Termites are colonial cockroaches. They are only distantly related to ants.
Termites live in colonies ranging from several hundred to several million strong. Like eusocial ants, termites divide labor among castes. But they breed differently. While bees and ants have exclusively imperial breeding habits, termites are more sexually democratic. Males and females mate repeatedly, though not necessarily monogamously.
Multiple fertile pairs typically exist in a termite colony. A termite queen may live 45 years.
There are both sterile male and female workers in a termite colony. Pheromones from the queen(s), spread through shared feeding, are instrumental in colony integration.
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In eusocial ants, bees, and wasps (order: Hymeoptera), females can decide the sex of their offspring by controlling which eggs are fertilized by sperm. Fertilized eggs become daughters. Unfertilized eggs become sons. This is known as haplodiploidy.
Hymeopteran females in a colony do all the work. Males (drones) are mere lazy breeders; hence the need for genetic control. An underproductive colony rapidly dissipates.
Termites are not haplodiploid. Termite genetics do not skew eusociality as they do in hymenopterans. They don’t need to. Males contribute to colony well-being as much as females.
Termites are eusocial in a distinct way, and for a different reason: food. Some termites chew wood for its cellulose, a rich energy source.
Termites themselves cannot digest cellulose. They rely on mutualist protozoa in their gut, acquired generationally as young termites, from feeding on adult fecal matter; the only way the necessary protozoa are put into a termite gut.
Only 1/4th of termite species chew wood with the help of digestive microbes. The other 75% keep fungal gardens, upon which they feed.
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Like all insects, termites are hygienic, though somewhat uniquely so. They groom one another to keep pathogens at bay, swallowing detritus to dispose of it. Their potent gut flora can terminate any unwelcome guests.
Fungus is an especial problem in the warm, humid climes that termites are fond of. The Formosan termite goes so far as to build pesticide protection into its nest.
The Formosan termite builds underground nests with extensive foraging galleries that spread to 150 meters. A colony may have more than a million members.
The inner lining of foraging galleries is coated with a sponge-like material composed of chewed wood particles mixed with feces. As with other animals, termite poop is packed with gut microbes. Termite stool includes relatively prodigious quantities of pathogen-pummeling bacteria. Lacing feces into constructions provides sanitary protection against common soil entomopathogens (insect pathogens).
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In a panic, humans, walruses, and ants try to escape pell-mell: pushing, shoving, even stepping on one another. In stark contrast, termites are unfailingly disciplined in their orderliness. To a termite, an emergency is no reason to panic. Workers establish single-file formations, with those in line following the ones in front. Meanwhile, soldiers get to either side of the worker flow, acting as protection to their sisters and brothers while moving along in an orderly manner.
If a termite slows down or stumbles, those behind stop and wait for it to right itself. No pushing please – we’re termites.
Termite etiquette owes to evolutionary history. Termites were the first animals to form societies 200 million years ago (MYA), some 50 million years before ants and bees cottoned to the benefits of large-scale eusocialism. Instilling social graces takes time.
Fungus Gardeners
Termites in tropical Africa and Asia practice fungiculture. The ancestors of these termites were the first insects to practice such cultivation, beginning at least 31 MYA.
Some species of Termitomyces – pseudo-Latin for termite fungus – are most commonly cultivated. Termitomyces forms a fruiting body if not cultivated by termites. This fruiting body is edible and sold in local markets and roadside stands in Africa, where the fungus and its pickers reside.
Fungus-cultivating termites live in large colonies, building elaborate cities which are visible as large mounds. The city spires of one African termite may reach 12 meters. Other species are more modest, with mounds 2 meters high.
These termite metropolises are engineering marvels. Mounds can survive fires and floods, though water can enter the inner chambers through the ventilation shafts and drown the termites inside; hence the height of fully-grown cities.
Termites use sophisticated techniques to regulate the internal environment of a city. Humidity, temperature, and atmospheric content are controlled. A city’s elaborate ventilation system enables the interior to have higher levels of carbon dioxide and humidity than the outside air.
Within a city, termites construct fungus gardens (combs) made of macerated plant material. Fungus comb construction is meticulous.
Termites forage for wood and other plant debris which they chew and swallow. These foragers return to the nest, whereupon they deposit the macerated botanicals as fecal pellets. These fecal bricks are taken by internal laborers to construct a comb.
The garden is inoculated with the fungus that is being maintained by the termites. A mycelium develops, and spreads throughout the comb. This turns the plant matter used to construct the comb into termite food.
The termites eat the comb infused with fungi, whose spores pass undamaged through the termites’ guts. The termites feed the fungi termite excrement. Completing the life cycle, the fungal spores hatch in the garden.
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Head Bangers
The African termite builds pyramidal mounds in the savanna, sometimes over 3 meters high. The mounds have a central chimney flanked by smaller buttresses. The structure is ingeniously architected to ventilate well and maintain a constant internal temperature, taking advantage of natural wind flows and diurnal outside-temperature fluctuations. Underneath lies a network of tunnels that radiate to foraging sites.
Soldier termites protect the mounds. They produce a drumming sound to alert others of an approaching aardvark or pangolin, their despised nemeses. The vibration comes from soldiers banging their heads on the ground 11 times per second. The initial knock is picked up by other soldiers.
Termite legs sense the beat. The slight delay between the leg that is nearer the sound and the one that is further away lets a termite know the direction that the vibration is coming from.
The African termite is not alone in using this technique. An estimated 15,000 insect species communicate via vibrations drummed through their nests, the ground, or another solid surface.
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Insects have extraordinary mental ability. They predict and then modify their behavior, communicating their conclusions, and (in the case of dancing bees) translating mathematical certainties into a coded form of dance which others will understand.
Conventional explanations are that these insects are simply pre-programmed, but their brains could not embody sufficient exigencies to meet all possible occurrences in their daily lives.
In their own way, these insects are solving problems and thinking. They are communicating in an insect’s way, deliberately, and in detail. ~ English biologist Brian Ford
