Mutualism Between Fungus-Growing Termites and Termitomyces

I. Description of the Symbiotic Relationship

When we speak of termites, the general notion of people is that of a swarm of insects destructively enigmatic to people and most of these pestering insects live in our houses and bigger industrial structures. Less popular to us is the family of fungus-growing termites more scientifically known as Macrotermitinae. Unlike other termites, these termites could not digest cellulose from the food they eat. Thus, they need help from the digestive capabilities of fungi; Basidiomycete Termitomyces. Macrotermitinae maintains a garden of Termitomyces around the colony and most of the time, create small ventilated structures inside the nest as fungi combs. As these termites consume cellulose-based materials like woods and fabrics, they also eat a certain amount of fungi. These fungi help the digestion of food inside the termites' bodies by gradually breaking down the ligneous and cellulose based substances. The other mutual way is that, termites carry back home all the consumed food and store them in fungi combs. Same process, the fungi breaks down the substances in order for the insects to completely digest them. Moreover, these fungi also help regulate the moisture content and the temperature within and around the colony.

In turn for the aid that fungi provide the termites, these insects help in the reproduction process of Basidiomycetes. When they eat fungi together with the cellulose-based materials that they consume, they could not digest the spores. As they defecate, they bring back the spores to the soil enabling them to grow. On the other hand, if they do not eat the fungi, they still aid in the reproduction by transportation. Fungi have the capacity to fructify, that is, to produce fruits from their bodies. From being a mycelium, a fungus emerges to the surface of the soil during fructification. When termites pass through the garden, they carry with them the fruits of fungi and causes horizontal transmission. Upon travelling to different places while foraging for food, the termites leave behind the fruits in different locations. Thus, the fungi could start a new growth.

II. Location of the Symbiants

Insect researchers and experts, otherwise known as entomologists, have recorded over 2000 species of termites around the world and most of these species live in African forests and deserts. Two of the places where they are mostly sighted are in Mozambique and Gorongosa. Moreover, there are approximately 160 Macroterminae subfamilies that exist in this continent which survive with the aid of the Basidiomycete Termitomyces. The co-existence of these two complex living organisms is apparent in green mounds. Not only in forests and deserts, these mounds could also be found in home yards and parks nowadays. They are more commonly sighted during rainy seasons. Fortunately for people, they do not live within houses because if they do, they would cause more structural damage than just having these termites consume the cellulose based materials. Aside from the hideous appearance of the colonies with small garden of fungi around it that could make the homeowners disgusted and embarrassed, the fungi could also cause health risks to the family members.

III. Their Positive and Negative Implication to Humans

Most of these macrofungi Termitomyces grow visibly around the mounds so it is very easy to immediately identify them. Some people even gather them for food. The mushrooms that sprout out during fructification are usually edible usually depending on the cleanliness of the area but since fungi are varied, there are also those that could not be eaten by humans and that are just beneficial to insects. For this reason, African people are very meticulous in picking up these mushrooms for consumption to avoid being poisoned. Moreover, a lot of delicacies and dishes could be made with these mushrooms that most of them have even become popular and fancied by a lot of people not only in Africa but also in other continents. The termites, on the other hand, have also become part of the rare and exotic range of delicacies in Africa. They are being prepared as grilled or toasted, sometimes sweetened or spiced.

Consequently, this co-existence also causes tremendous damage to humans especially to the crops being maintained for a living. It has been reported that 90% of the crops in Africa has been terribly infested by fungus-growing species of termites and the genus of termites mostly responsible for this is the genus Odontotermes. They have the highest rate of growing fungus and have large mounds exhibiting the symbiotic relationship. However, with their presence, they could also yield up to an approximate crop damage of 25%. This percentage is already too much for the African people who greatly depend in farming for survival. Thus, despite their food benefits, they are also considered as enemies. Most people destroy the mounds after gathering the mushrooms around it if they have just discovered them late enough for the fructification to be completed. They usually burn the mound or use poison chemicals to annihilate the termites.

IV. Natural Conservation for Ecological Benefit

It is already common to our knowledge that termites play a great role in the ecological life cycle and it has already been publicized and tackled in a lot of articles either virtual or not. Needless to discuss further, fungus-growing termites also have a different contribution to nature. Most of the time, their mounds are big enough to shelter small animals during rainy season. They also serve as refuge to small animals when there is flood. Moreover, these mounds also provide growing mediums for different kinds of shrubs that have weak root systems. They support these plants during inundation because the roots could not withstand a prolonged flood. Birds, scorpions, snakes, lizards and all other small ground creatures use the abandoned mounds as their own habitats since they provide great protection especially to the eggs and young ones. Burrowing mammals like aardvarks also find it easy to create passages and caves and eventually, hyenas and mongooses live in the enlarged ground spaces. The mounds in timbers, on the other hand, also serve as shelters to small timber-inhabiting creatures. The abandoned timber mounds could also be ideal bird nests.

V. Conclusion

The symbiotic relationship between Macrotermitinae and Basidiomycete Termitomyces has proven that termites are not just pestering insects solely advantageous to the ecological life cycle but are also essential contributor to the survival of other living creatures. They may cause great damages but they also serve much advantage to other organisms and smaller animals which play more advantageous roles in nature. Thus, this mutualism between termites and fungi has become a very interesting topic for researchers of a lot of science professionals. A lot of entomologists are devoting much of their time and funds just to fully comprehend the existence of these complex organisms. Since there are different kinds of termites and fungi involve in this mutualism, more studies are expected to sprout out in the near future.

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Michael Rozatoru :)