The Northern Harvester Termite Hodotermes mossambicus performs a vital ecological role. This termite species is an essential component in the nutrient cycle and is an incredibly important source of food for a multitude of animal species. Their tunneling activities also greatly improve aeration of the soil and rainwater penetration. They are ecosystem engineers.
This termite occurs widely across the northern parts of South Africa in the Savanna, Grassland and Nama Karoo biomes. They prefer disturbed or overgrazed areas. Their nests are subterranean and not generally visible above ground. Their colonies are huge with many separate yet interconnected nests or hives, each around 60 cm in diameter and surrounded by grass storage chambers which are filled with white nymphs that resemble grains of rice. This has led to the Afrikaans name of ‘rysmier’ (rice ant). The many interconnected hives cover an extensive area. Hundreds of tunnels radiate from each hive with openings to the surface where the termites can emerge to forage.
They feed mostly on dry grass but they also take a wide variety of other plant material such as twigs and dry herbivore dung. They are able to remove between 1 and 3 metric tons of dry forage each year and heavy infestations can quickly deplete the veld.
The Northern Harvester Termite is unusual in that the bodies of the soldiers and workers are sclerotised (hardened) and darkly pigmented which protects them against ultraviolet radiation. This allows the workers to forage in the open on sunny days, giving them a competitive advantage over other termite species which are unpigmented and lack sclerotised bodies.
After summer rain showers the winged reproductive caste, known as alates, emerges from the tunnels en masse. These alates comprise both males and females and if all goes well they will become future kings and queens of new colonies. Alates are easily recognised by their elongate, fat bodies, long wings and well-developed eyes. They shed their wings soon after their dispersal flight and males and females locate each other through scent pheromones which the females produce.
From the alate’s perspective, things normally do not go well. The swarms of emerging alates become a nutritious snacks for the multispecies flocks of birds which gather for the feast.