Macrotermes gilvus
This is one of the largest species of termite in Asia. The workers which make up the bulk of the colony are 4 - 6 mm in length and the large majors are about 10 mm in size. Although their bodies are very soft and they lack a sting the majors are armed with a powerful set of mandibles which they will use to protect the colony.
This species of termite maintains a large fungus garden. The fungus is housed on a special substrate inside their nest called a fungus comb. The workers collect and chew on cellulosic materials like dried leaves, twigs and dead wood and bring these pre-masticated materials back to the workers in the nest. Workers inside the nest then add it to the fungus comb to nourish their fungus garden. As the fungus garden matures small white fruiting bodies form, which are then eaten by the adults and fed by regurgitation to the nymphs.
They have mass swarms for one or two days every year. The alates are about 12 - 15 mm long, and those that survive the onslaught from the numerous predators will fall to the ground and form pairs, and then search out a suitable place to start a colony. After fertilization as the colony grows and food becomes unlimited the queen will swell and increase in size. The largest queens I have found in the wild have been about 6 cm, although it is possible that they could reach a larger size in very mature colonies.
Unlike ants when termites swarm the male alate joins and stays with the female for colony foundation. Mating does not take place until the pair have constructed a secure chamber underground and have settled down.
From field observations, it has been discovered that many of the males do not survive long after the colony foundation. It may be that they are eaten by the females as a source of nutrition, or simply that they do not live very long. Observations of natural wild colonies have revealed that only about 40% have both a queen and a king present.
Females are said to mate several times throughout their life and if this is the case then a mating is probably sufficient for several years before egg production falls away. In colonies where the male has died, the workers will hold back a male alate to act as a new king and mate with the queen.
Termites hatch directly from the eggs laid by the queen and do not undergo a metamorphosis of eggs, larvae and pupae like ants. Eggs are a yellowish colour when laid but turn white just prior to hatching. They can take four weeks to hatch and the nymphs another six weeks to mature. The nymphs are miniature adults when they emerge from the eggs and as they age, they will shed their skin and increase in size. Initially, the new nymphs will just hang around the fungus garden being cared for by the adult workers. However, as they near the adult size they start involving themselves in the colonies work.
The colonies are slow to initially establish, but once they have a credible force of workers and an established fungus garden, the queen will swell and turn into a prolific egg-laying machine, and the colony will increase in size very quickly.
In the wild, they are found nesting in both lowland and highland habitats, usually in the dappled shade of mature forest but occasionally in more open areas at the edges of forests. They do not like being disturbed and are not found near cultivated ground. The colonies are quite populous and fully mature colonies will contain tens of thousands of adults and nymphs.
This species does not build a mound until the colony is several years old, but the surface of the ground just above the nest of younger colonies is covered with a thick layer of very hard clay-like material. This layer can be 5 - 10 cm thick and helps protect the main nest and fungus garden from excessive rain and would-be predators. It may also act as a thermal shield reducing the daily temperature fluctuations and enabling the termites to maintain a more stable temperature within the nest.
During the day the adults tend their fungus garden and care for the young. At dusk and throughout the night they will send out ‘swarm parties’ to forage over the surface of the ground, looking for suitable food which they collect and take back to the nest. While outside the soft-bodied workers are protected by the heavyweight soldiers who act as guards and patrol along the edges of the swarm.
They are a night-active species and will usually only forage during the hours of darkness. This helps protect them from predators and is also when the humidity is at its highest. However, in the rainy season, when it is very dull and humid, they will also go out foraging during the day.
This species is capable of acoustical communication and when alarmed the soldiers will knock their heads on dry leaves etc. creating an audible rattling noise. This helps to scare off predators and the vibrations produced warn their companions that there is potential danger nearby.
In mature colonies, the fungus garden can be the size of a football and is positioned about 10 - 20 cm below the ground. The whole garden is surrounded by a thin earthen shell, and by altering the number and size of ventilation holes in this protective shell the termites can control both the temperature and humidity of the nest area.
The termite-fungus relationship is called symbiotic, and both the termites and fungus benefit. The termites provide a growth substrate and a protected growth environment for the fungi, and in return, the fungus provides a nitrogen-rich food source for the termites.
The fungus garden is kept in control by the workers and neglected gardens or gardens without enough workers to care for them will destabilize very quickly, producing a mass of invasive white filaments. These gardens are then unusable to the termites and are quickly abandoned.
Cultivation.
Hints on keeping in captivity: There is not much information available on keeping this species of termite in captivity. This does not mean it cannot be done, simply that others have not done it before.
Termites are soft-bodied and don't have a thick strong exoskeleton like ants, hence they can dry out very quickly. From observations made with captive colonies, they should have a humidity level of between 80 - 90% in their nesting chamber. This humid environment is very important for the growth of the fungus garden. A stagnant humid environment should however be avoided, as this will create conditions that could lead to the fungus garden becoming unmanageable. Outside the nest, in the foraging area, the humidity level should be much lower. This will create a humidity gradient which the termites can utilize to ventilate their nesting chamber. They will also require a constant supply of water. In the wild, during times of drought, they can be seen foraging early in the morning for the sole purpose of collecting moisture from the morning dew.
Temperature is also very important and although they live in areas where the winter night temperature often falls to about 10 - 15° Centigrade, the heat absorbed by the surrounding earth during the day is slowly released at night, and this helps shield them from wide temperature fluctuations. An average temperature of 23 - 25°C is recommended. Lower and higher temperatures can be tolerated for a few days, but you should try and avoid any rise above 28°C which has been reported as being detrimental to their fungus garden.
They should be provided with an assortment of potential food so they can select what they need. Dead leaves, mixed leaf litter, very small twigs, even freshly cut grass and other plant stems seem to be used. There are also records of them utilizing paper and cardboard.
Some resources state that the spores of the initial fungus garden are carried in the gut of the alates and are regurgitated to the first workers thus enabling them to start the new fungus garden. Other information states that the workers pick up the required spores shortly after they start foraging in the wild. As the information about this seems a bit vague it would be advisable to place a small amount of established fungus garden in the foraging area, so the first workers that go foraging can if required collect the fungus spores.
Each order for alates from us will also receive a fungus spore mix. This should be stored dry, at room temperature until the first workers start foraging, then it can be spread around their foraging area. The workers can then collect what they need to start their fungus garden.
Artificial nests: The foundation nest for alate pairs should consist of several different sized chambers about a cm in-depth and there should be a small amount of moist earth scattered in each chamber. The alates will use this earth to seal themselves into one chamber. This gives them a feeling of security and helps them settle down. As the first workers mature, they will break down the earthen seal and start to utilize the additional chambers. The nest chambers need not be very deep at the early stages of colony foundation as it will be some time before the female alate starts to swell. The earth addition will also enable the termites to control the inside environment to some degree, as they will use it to seal around the sides of the chambers and reduce the size of the entrance. They will however also use it to slowly construct a covering over portions of the glass rendering observation difficult, so you will need to remove and clean the glass cover about once a month if you want to maintain full observation.
Another method that can be used to cultivate more mature colonies is the 'semi-natural environment' within an aquarium type set-up. Here a thick layer of soil can cover the base of the aquarium and the surface landscaped with plants, pieces of wood, bark etc. Once the colony has settled down and selected a place to construct their fungus garden, a part of the soil covering their nest can be removed and replaced with a glass observation cover. An additional wooden covering over the glass will ensure the termite’s nesting area is kept dark, but allow you to observe them when required.
Availability: The easiest and cheapest way to obtain this species is to purchase a pair of alates. These alates are usually available for sale in May/June. The main disadvantage of starting a colony this way is that it can take a long time to establish a reasonably sized colony.
Young wild-collected colonies are also occasionally available. These colonies are difficult to locate in the wild, and they have to be kept in captivity for several weeks to ensure that they re-establish and are viable before being offered for sale. Hence, they are expensive, but obviously have the advantage of giving you an instant colony.
Summary: A fascinating species, but a challenge to keep in captivity and only recommended for experienced hobbyists.