The ecology and foraging behaviour of the harvester termite, Baucaliotermes hainesi in semi-arid grasslands in the northwestern interior of South Africa

Abstract

Termites, and in particular species that remove live plant material, play an important role in rangeland deterioration in the arid areas of the world. In the arid parts of southern Africa, where the sparse vegetation is important for subsistence and large-scale game farming, it is vital to understand termite ecology and feeding behaviour. Here, we focus on the termite species, Baucaliotermes hainesi, the most common termite species within its range in the arid interior of southern Africa. We determine B. hainesi foraging and nest maintenance activities, predator response and the preferred food plants. The study was conducted during 2014 in the Nama-Karoo biome of South Africa. We found that Baucaliotermes hainesi is strictly a nocturnal species and that temperature is the most important abiotic determinant of foraging activity. Below 14 °C, no foraging takes place, whilst maximum foraging activity is observed only above 20 °C. Only three plant species are foraged upon, with the grass Stipagrostis uniplumis utilised the most. We suggest that B. hainesi can significantly reduce grass cover, particularly in overgrazed areas and in dry years. Further studies to elucidate the effects of drought, overgrazing and the role of B. hainesi in veld degradation are critical, in particular under future climate scenarios that the predict aridification of B. hainesi habitat.