Wikipedia
The Amitermitinae constitute a subfamily of harvester termites and allies (family Termitidae) in the Isoptera infraorder. They have been merged with the Termitinae subfamily and are considered by ITIS as an invalid taxon. However, a case could be made to keep them in their own subfamily because they have some important attributes that affect soil.
The Amitermitinae subfamily consists of 18 genera and 296 species. They have as typical characteristics a usually rounded head and a bilobed clypeus. The mandibles of their soldiers have usually a single median tooth.
They have evolved the ability to have many reproductives in their colony, up to a hundred, which allows very large colonies. As with other members of their Termitidae family, they have lost most of their cellulose-digesting protozoa. Instead, they digest fungi, which digest the cellulose and other organic matter. As a result, the Termitidae can make use of a wide variety of foods; not only rotten wood, but also grass, seeds, dung, soil, and detritus are all used by one species or another. In addition, some species can synthesize nitrogen compounds.
Many members of the Amitermitinae have evolved a very effective way of securing food. The Amitermes genera especially build a shell of earth by cementing the earth with their saliva and use it to cover vegetation. This smothers the plant and they can then eat the fungi that grow in the safety of the covering. They probably evolved in savanna, monsoon, and desert regions because their runways are not very resistant to rain erosion They use saliva to build runways, and this is an adaptation of an earlier use of saliva to entangle enemies
The cemented soil is richer in phosphorus than the soil from which it is derived. This causes an increased loss of phosphorus from sheet erosion. It is probably a major part of the reason why tropical savanna soils are depleted in phosphorus, especially in Australia. The Termes genus branch probably arose in Africa. The Amitermitinae are thought to have arisen in Southeast Asia, probably from primitive Oriental Termitinae species, in early Cretaceous but it may be even more likely in Australia, since that is where phosphate deposits were clustered in the late Jurassic and early Cretaceous. The primitive Amitermitinae species are most numerous in those regions at present. The development of at least 25 fundamentally different sesquiterpenes and several unique cyclic ethers for termite defense in the Amitermitinae hint at considerable success and large numbers in the early years for such systems must be elaborate to evolve.