Monthly sampling of 71 laboratory nests, each with a pair of adults, revealed that eggs and first-instar larvae were observed in the third month, minor workers in the fourth month and minor soldiers in the seventh month. Mortality of the pairs was high, with only five pairs surviving over the 10 month period. Laboratory nests did not develop further than the copularium. Excavation of 30 nests, of differing sizes, revealed that five were juvenile nests, consisting of only thin shelving with a few flattened fungus combs scattered throughout, and all, even the youngest nest (3 to 5 years), had a small mound. The queens from these young nests were small and had white pleural and intersegmental membranes. Twenty mature nests had a medium to large mound with large air passages and a medium to large hive with a well defined fungus garden containing large fungus combs. The queens from these nests were medium- to large sized, with white to brown pleural and intersegmental membranes. The remaining five nests had mounds often covered with grass, and a hive that contained less fungus comb than expected. The mounds of these nests were classified using their sandy pediment or crumbly texture. These were senescent or declining nests. The queens had pale brown pleural membranes and brown intersegmental membranes, and were often flaccid. The royal cell was commonly found in the middle to upper part of the nursery (20 nests), but sometimes was found at the edge of the nursery (five nests). The royal cells of five nests were not found or had been destroyed during excavation. The "youngest" mound was one to two years old and the "oldest" was more than 25 years old. The youngest queen was estimated to be three to five years old and the oldest queen more than 27 years. The nest seems to remain subterranean for two or less years before producing a mound. Thirteen nests were vigorous and five declining. The remaining 12 nests could not be classified as no fungus comb was collected from the nests. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1997.

This thesis reports on the number of individuals in Macrotermes natalensis (Hav.) colonies, their biomass and food consumption in the northern Kruger National Park (KNP). The ecology of M. natalensis is largely undocumented despite the abundance of colonies in southern African savannas. New approaches to mound excavation, sub-sampling and data management are introduced. Via the intracolonial demography of colonies the contribution of each caste in number or proportion is determined. Using this information in combination with body mass and mound density data, biomass per unit area has been computed indicating the importance of this termite in synecology. The measurement of food consumption gives further insight as to how much litter is removed, fragmented and redistributed as nutrients in the ecosystem. Mounds were completely excavated, termites collected by means of vacuuming, and colony size estimated by sub-sampling. It was estimated that, on average, small mounds contain more than 5 000, medium mounds more than 45 000, and large mounds more than 200 000 individual termites. A highly significant relationship between total number of individuals (N ) and mound height (h ) was found, given by lnN = 7.893 + 1.093h (r = 0.92). The proportion of soldiers was found to change as colonies grew larger. In order to derive biomass estimates, a statistical bootstrap procedure was carried out using three databases: body mass, colony population sizes and mound density. Live biomass for small, medium and large mounds was found to be 0.17, 1.40 and 4.16 kg. Dry/wet body mass ratios were established for workers (23.7 %), major soldiers (20.3 %), minor soldiers (35.3 %), nymphs (17.1 %), king (35.4 %) and queen (20.8 %). Average live and dry biomass was calculated to be 0.51 kg/ha (0.051 g/m2) and 0.11 kg/ha (0.011 g/m2). Geology, geomorphology, elevation, local relief, soil patterns and annual rainfall were the abiotic factors shown to be most influential in determining termite biomass, either directly or indirectly. Termite biomass is high in undulating areas where the elevation is 250-400 m, where granitic and rhyolitic soils occur, and where annual rainfall is high (650-700 mm) in the context of the region. Major workers fetch woody litter outside the nest through ingestion into the section of the crop and gizzard. Gut contents were dried, weighed, ashed and reweighed. The ash mainly represents soil particles. The ash-free mass of food that is consumed during a single foraging trip by a foraging individual is 0.166 ± 0.009 mg (CI). Frequency of foraging trips between the mound and food source was observed using translucent tubing. The annual food consumption is given by the formula 365mnp/t , where m = individual mass of ashed crop-gizzard contents, n = number of foraging major workers, p = daily foraging period, and t = individual time spent between nest and food source. Food consumption of this termite in the northern KNP is calculated to be 20.2 kg/ha/yr. It is shown that termites are primary decomposers and contribute to litter fragmentation and the recycling of nutrients into the soil. This thesis gives greater insight into aspects such as colony development, biomass investment and resource utilization of M. natalensis in the northern KNP. / Dissertation (PhD)--University of Pretoria, 2003. / Zoology and Entomology / unrestricted

The fungus growing termite species Macrotermes bellicosus (M. bellicosus) is used in nutrition and traditional medicine in the Republic of Benin for the treatment of infectious and inflammatory diseases. Previous findings demonstrated evidence of anti-inflammatory and spasmolytic properties of M. bellicosus. The aim of the present study was to evaluate the antimicrobial potential of different extracts of M. bellicosus samples and determine the chemical profile of an ethanolic M. bellicosus extract. Chemical profiling was conducted using centrifugal partition chromatography and 13C-NMR, followed by MALDI-TOF MS. Major identified compounds include hydroquinone (HQ), methylhydroquinone (MHQ), 3,4-dihydroxyphenethyl glycol (DHPG), N-acetyldopamine (NADA) and niacinamide. The fatty acid mixture of the extract was mainly composed of linoleic and oleic acid and highlights the nutritional purpose of M. bellicosus. Using the Kirby–Bauer disc diffusion and broth microdilution assay, an antibacterial activity of M. bellicosus samples was observed against various clinical strains with a highest growth inhibition of S. aureus. In addition, HQ and MHQ as well as fractions containing DHPG, niacinamide and NADA inhibited S. aureus growth. The reported antimicrobial activity of M. bellicosus and identified active substances provide a rationale for the traditional medicinal use of M. bellicosus.