Diversity, nesting behaviour, thermoregulation and cephalic secretions of termites from two Nigerian savannahs

Abstract

Seven species of mound building termites from five genera were identified thus; Amitermes evuncifer, Cubitermes oculatus, Macrotermes bellicosus, M. subhyalinus, Odontotermes sp., Trinervitermes geminatus and T. occidentalis. Deviating from the norms of using the traditional soldiers’ morphology alone for identification, a proposed identification keys for mound building termites in the savannah using both morphological characters and mound structures were introduced. Two or three of the four types of mound structures; dome, cone, cathedral and mushroom were identified to be associated with the seven species of termites from the Sudan and Sahel savannahs. To address a taxonomic gap especially on termites from West Africa, a novel chemotaxonomic approach that profiles cephalic and cuticular secretions from termites was used to identify them to species level. Termites are known for their abilities to regulate microclimatic conditions within their nests and keep them at optimum through the mounds that they build or the location where they build them. These mechanisms of regulations have been shown to vary between species, with some species adapting passive or active behaviour such as nest site selection and nest structures that permit passive heating or cooling. However, little is known if same species of termites would use similar or different nest cooling mechanisms when they occur in different habitats i.e. if the environment does influence such behaviour. The findings show that most of the termite build their mounds in the shade as against the open in areas with high temperatures indicating preferences for nesting sites. Mound architecture was also found to play a role in thermoregulation within the termites’ mounds. The thesis also looked at the diversity, density, location and types of termites’ mounds from two Nigerian savannahs. It further compared the architectural designs of the mounds built by these species to find out the modes of thermal regulations used.