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The aim of this study was to assess the physico-chemical characteristics and fatty acid profile of oil from termite (Macrotermes subhylanus), green and brown long-horned grasshopper (Ruspolia differens). The insects were harvested in Siaya county of Western Kenya from the wild during swarming seasons. Physico-chemical characteristics of insects oil and the effect of two traditional heat processing methods (frying and solar drying) on the fatty acid profile were determined using standard methods. The insects oil was a clear, golden or light yellow colored liquid at room temperature, with a low solidification temperature (8–12 °C) for M. subhylanus and10–15 °C for R. differens. M. subhylanus showed an iodine value of 83.51 g iodine/100 g oil, peroxide value 0.19 mEq/Kg, saponification value 160.61 mg KOH/Kg and 38.77 mg/100 ml of total cholesterol. R. differens showed an iodine value of 86.97 g iodine/100 g oil, peroxide value 0.13–0.14 mEq/Kg, saponification value 229.67–234.40 mg KOH/Kg and 27.51–31.40 mg/100 ml of total cholesterol. Oleic acid was the major fatty acid in all the fresh insect samples (M. subylanus 52.1%, green R. differens 43.2%, brown R. differens 37.1%) while palmitic acid was the second most abundant fatty acid. Total unsaturated fatty acids were proportionately more than the total saturated fatty acids. The level of saturated fatty acids increased from fresh insect samples to heat processed samples (fried, fresh-dried and fried-dried), while the level of unsaturated fatty acids decreased with processing though insignificantly. The insects have high quality oil that maybe exploited in processing of nutritional food products and they may therefore be heat processed domestically without adversely affecting the quality of the oils.

This study evaluated the effects of three different land use types: mango orchards, maize fields and communal grazing lands on termite species distribution in the Vhembe District, Limpopo Province, South Africa. The main objective was to identify the termite species found in the area and investigate the effect of land use on termite species. Termites were collected from six study sites using a standardized transect sampling protocol and baiting methods in a transect of 2 × 100 m during the dry and wet seasons. A total of 18 termite species from 2 families (Termitidae and Rhinotermitidae), 5 subfamilies (Macrotermitinae, Amitermitinae, Apicotermitinae, Nasutitermitinae and Cubitermitinae) and 11 genera (Allodontotermes, Ancistrotermes, Macrotermes, Microtermes, Odontotermes, Microcerotermes, Rhadinotermes, Trinervitermes, Psammotermes, Schedorhinotermes and Cubitermes) were recorded. A higher species diversity index was observed for the wet season. Communal grazing resulted in a higher Shannon diversity index (H′) of 2.23 and Simpson diversity index (1-D) of 0.84 followed by mango orchard (H′ = 1.41, 1-D = 0.68), while maize field recorded the lowest (H′ = 1.07, 1-D = 0.48). Macrotermitinae constituted 77% of the total number of species recorded across all the land use types. Edible termite species recorded are important in rural communities to supplement human protein requirements and they provide ecosystem services thus, there is a need for studies that quantify the trade-off between costs (crop damage) and benefits of maintaining termites in agricultural landscapes.

Termites are commonly used by smallholder farmers in West Africa to feed their poultry. A survey was carried out among poultry farmers in Burkina Faso to gather knowledge on the traditional methods used to obtain termites for poultry feed, to assess which termite genera are collected with which techniques and evaluate prospects for optimising and improving the collection and trapping methods. Data were collected among 1100 poultry farmers in eight regions of Burkina Faso on the harvesting techniques, the termite species and their local names as well as on the use of residues. After the interviews, termite samples were collected with the farmers and identified in the laboratory. At least five termite species were found. Species of the genera Odontotermes, Trinervitermes and Macrotermes are commonly given to chickens and guinea fowls whereas a Cubitermes species is sometimes used to feed guinea fowls. Two categories of methods are used to obtain termites, the direct collection by breaking termite mounds and the trapping of termites in containers filled with organic matters. The harvesting method varies with the termite genus, the region and the season. Different techniques with various types of containers and organic matters are used in the country and these techniques should be tested and compared to recommend the most efficient ones. The enhancement of termite trapping methods and their integration in poultry feed have the potential to significantly improve traditional poultry farming in Burkina Faso.

In African savannahs, mound-building termites induce higher diversity in plant communities. Biotic and abiotic filters, such as nutrients and disturbances (for example, herbivory or fire), may influence the distinct vegetation on termite mounds; however, seed dispersal has not yet been evaluated as a filter in this ecosystem. This study examined the effects of seed dispersal, particularly animal seed dispersal, on the distinct woody plant community on termite mounds in a mopane woodland in north-western Namibia. We compared the functional traits of woody plants related to dispersal, as well as responses to resource availability and disturbance, between plant communities on and those off termite mounds. We conducted vegetation surveys of woody plants in 13 paired mound–savannah plots and measured their functional traits. Soil samples were also collected from 10 of the 13 plots for soil chemical analysis to compare the differences between mound and savannah plots. Drupe-type fruits and dispersal by animals, including mammals and birds, were more dominant in plant communities on termite mounds, whereas pod and winged fruits and wind-dispersed species were typical in matrix communities. Termite mounds were rich in soil nutrients compared with the surrounding matrix, and soil phosphorus was associated with mound soil. We conclude that dispersal mechanisms contribute to the distinct and diverse woody plant community on termite mounds. Seed dispersal by animals is likely to be more common in the distinct woody plant community of the mounds, whereas the community in the surrounding matrix was characterised by wind dispersal.

With global change, microclimates become important refuges for temperature-sensitive, range-restricted organisms. In African savannas, woody vegetation on Macrotermes mounds create widely-dispersed microclimates significantly cooler than the surrounding matrix, which buffer against elevated temperatures at the finer scale of mounds, allowing species to persist at the landscape scale. Termite colonies cultivate symbiotic fungi to digest lignin, but the fungi require temperatures between 29 and 32 °C, which termites strive to maintain. Mound-associated vegetation is a hot-spot for elephant herbivory, so removal of woody species cover by elephants could influence mound-associated microclimates, impacting temperature regulation by termites. We explored the interaction between two prominent ecosystem engineers (termites and elephants) to ascertain whether elephant removal of mound woody cover affects (1) external mound-associated microclimate and (2) internal mound temperature. We surveyed 44 mounds from three sites in Kruger National Park, South Africa, during an El Nino/Southern Oscillation-induced drought and heatwave, recording whether sub-canopy, external, mound-surface and internal mound temperatures varied with vegetation removal by elephant. Elephant damage to mound-associated vegetation reduces the fine-scale microclimate effect provided by vegetation on Macrotermes mounds. Despite this, termites were able to regulate internal mound temperatures, whereas internal temperatures of abandoned mounds increased with elevated surface temperatures. Termites can persist despite loss of mound-associated microclimates, but the loss likely increases energetic costs of mound thermoregulation. Since mound vegetation buffers against drought, loss of widely-dispersed, fine-scale microclimates could increase as megaherbivores remain constrained to protected areas, impacting climate-sensitive organisms and ecosystem function at a range of scales.

Understanding the link between termites' impact on ecosystem functioning and their ecological needs remains a key question in ecology. This study focused on the influence of the fungus-growing termite species, Hypotermes obscuriceps, on soil properties in Southern India. This species produces soil sheetings and mounds on the ground. In contrast to other termite species, such as those belonging to the Macrotermes and Odontotermes genera, which produce mounds to live in, H. obscuriceps excavates soil above ground for constructing its chambers below ground. Using a captive colony of H. obscuriceps growing up in control conditions, we measured the soil properties (carbon content, particle size distribution, pH, electrical conductivity and concentration in soluble anions and cations) of its mound and of the sheetings it produced over the leaves of Acacia auriculiformis and on the branches of Ipomoea carnea and Lantana camara. The physical and chemical properties of H. obscuriceps mounds were very similar to those of the surrounding soil and even if rain erodes these mounds in the field, it is likely to have only a small effect on the resulting run-off water quality. In contrast, sheetings have higher clay and C contents than the surrounding soil. Their degradation by rain is likely to be associated with soil detachment and F-, Cl- and K+ export in water runoff and/or leachate. In conclusion, this study shows that this species impacts soil properties more through the construction of sheetings than mounds. This difference is explained by the ecological needs of termites. While H. obscuriceps is not dependent on soil mound properties for survival, soil sheetings' properties are essential for providing them a protective cover.

Background Termites are an important food resource for many human populations around the world, and are a good supply of nutrients. The fungus-farming ‘higher’ termite members of Macrotermitinae are also consumed by modern great apes and are implicated as critical dietary resources for early hominins. While the chemical nutritional composition of edible termites is well known, their microbiomes are unexplored in the context of human health. Here we sequenced the V4 region of the 16S rRNA gene of gut microbiota extracted from the whole intestinal tract of two Macrotermes sp. soldiers collected from the Limpopo region of South Africa. Results Major and minor soldier subcastes of M. falciger exhibit consistent differences in taxonomic representation, and are variable in microbial presence and abundance patterns when compared to another edible but less preferred species, M. natalensis. Subcaste differences include alternate patterns in sulfate-reducing bacteria and methanogenic Euryarchaeota abundance, and differences in abundance between Alistipes and Ruminococcaceae. M. falciger minor soldiers and M. natalensis soldiers have similar microbial profiles, likely from close proximity to the termite worker castes, particularly during foraging and fungus garden cultivation. Compared with previously published termite and cockroach gut microbiome data, the taxonomic representation was generally split between termites that directly digest lignocellulose and humic substrates and those that consume a more distilled form of nutrition as with the omnivorous cockroaches and fungus-farming termites. Lastly, to determine if edible termites may point to a shared reservoir for rare bacterial taxa found in the gut microbiome of humans, we focused on the genus Treponema. The majority of Treponema sequences from edible termite gut microbiota most closely relate to species recovered from other termites or from environmental samples, except for one novel OTU strain, which clustered separately with Treponema found in hunter-gatherer human groups. Conclusions Macrotermes consumed by humans display special gut microbial arrangements that are atypical for a lignocellulose digesting invertebrate, but are instead suited to the simplified nutrition in the fungus-farmer diet. Our work brings to light the particular termite microbiome features that should be explored further as avenues in human health, agricultural sustainability, and evolutionary research. Electronic supplementary material The online version of this article (10.1186/s12866-019-1540-5) contains supplementary material, which is available to authorized users.

Baiting is considered to be a relatively environmentally benign termite control method; however, all commercial baiting systems are designed for species in the Rhinotermitidae and are used primarily in temperate countries. Fungus-growing termites in the Macrotermitidae can be important pests in tropical countries; they can be difficult to control using all available methods, and there are no baiting systems designed for them. We tested bait station size, an important component of bait station design, against two Macrotermes species in Singapore. Macrotermes gilvus recruited to small stations (0.35 L) very poorly and medium stations (3.6 L) poorly (both similar in size to various commercial stations), but they recruited to large stations (11.5 L) well. Macrotermes carbonarius followed a similar pattern but recruited to fewer stations overall. In the occupied stations, M. gilvus ate the bait wood, sometimes creating a fungus garden inside the stations, and brought little soil into the stations. In comparison, M. carbonarius ate no wood at all, but filled stations with soil. There was significantly less leaf litter around M. carbonarius mounds compared with M. gilvus mounds, although there were no obvious differences in habitat, which suggested that M. carbonarius eats leaf litter only and is not a pest species. Our study shows that stations much larger than current commercial options may provide a useful means for controlling pest wood-eating, fungus-growing termites in tropical countries.

Small lenticular soil mounds are scattered in several African savannahs. At Lamto, Cote d’Ivoire, most of these lenticular mounds house nests of Odontotermes aff. pauperans which have to date been thought to have built them. However, repeated observations made in 2000 and 2015 supply several arguments in favour of another hypothesis, namely that after a nest of Macrotermes has been abandoned and eroded, it could be colonized by O. aff. pauperans and subsequently maintained, stabilized, by this latter species or possibly recolonized by another Macrotermes society.

Spatially heterogeneous habitats often promote woody plant species and functional diversity (FD). Ungulate herbivory can have the opposite effect. Across the globe, the type and intensity of herbivory is changing, as domestic livestock replace wild ungulates, which are increasingly confined to protected areas. Despite recognition of the importance of FD for ecosystem functioning, the interactive effect of soil-related fine-scale heterogeneity and larger-scale ungulate herbivory on woody plant FD is little-known. In miombo woodland of Zimbabwe, we investigated (1) how bottom-up fine-scale heterogeneity created by Macrotermes termitaria interacts with top-down effects of herbivore foraging-guilds on woody plant FD; and (2) whether browsing combined with grazing impacts FD more than grazing alone. The three different herbivore treatments (grazing, combined browsing-and-grazing, and exclusion) had been maintained for 50 years. We surveyed 10 termite mound-matrix plots within three sites per treatment. We assessed woody plant traits and FD across treatments (herbivore feeding-guild) and position (mound or woodland-matrix), and interactive effects between these. Woody plant FD was greater on mounds, and lowest overall with browsing-and-grazing. Specific traits were associated with position (e.g. palatability was greater for mounds), and treatment (e.g. spinescence increased with grazing). Long-term enclosure of ungulate herbivores (browsing-and-grazing, and grazing alone) decreased woody FD, but this was mitigated by termitaria. The novel finding is that at regional scales, mounds can enhance woody plant FD despite the impacts of herbivory. At broader scales encompassing the miombo system, potential exists for mounds to stabilise woody plant FD from livestock-induced impacts.

Fine-scale spatial heterogeneity influences biodiversity and ecosystem productivity at many scales. In savanna systems, Macrotermes termites, through forming spatially explicit mounds with unique woody plant assemblages, emerge as important sources of such heterogeneity. Despite a growing consensus regarding the importance of functional diversity (FD) to ecosystem processes, no study has quantified how termite mounds affect woody plant FD. We address whether termite mounds alter the distribution of functional traits, and increase FD of woody plant communities within Africa’s largest savanna woodland, the 2.7 million km2 miombo system. Using plant traits that change according to soil resources (for example, water and nutrients), and disturbance (for example, fire and elephant herbivory), we identified response functional groups and compared relative representation of these groups between mound and matrix habitats. We also asked whether mound and matrix habitats differed in their contribution to FD within the system. Although species representing most functional groups were found in both mound and matrix habitats, relative abundance of functional groups differed between mound and matrix. Mound plant assemblages had greater response diversity to soil resources than matrix plots, but there was no difference in response diversity to disturbance. High trait values on mounds included tree height, leaf nitrogen, phosphorus, and palatability. Species with root ectomycorrhizae dominated the matrix. In conclusion, these small patches of nutrient-enriched substrate emerge as drivers of FD in above-ground woody plant communities.

Large herbivores and termites are important functional groups in African savannahs. Both groups affect small mammals, which are also important determinants for savannah structure and function. Because vegetation on Macrotermes mounds are preferentially grazed by large herbivores, and mounds represent resource-rich distinct habitat patches for small mammals in relatively resource-poor savannahs, termite mounds are ideal sites for studies of how grazing by large mammals and productivity affect communities of small mammals. We conducted an experiment in Lake Mburo National Park, Uganda, with four treatments: large vegetated Macrotermes mounds (with and without large herbivores) and adjacent savannah areas (with and without large herbivores). We replicated the treatment blocks nine times and trapped small mammals regularly over a period of almost 2 years. Small mammal species assemblages differed considerably between mounds and savannah areas. Grazing had a substantial effect on small mammal species assemblages in the resource-poor savannah, but not in the relatively resource-rich termitaria. Small mammal species abundance, biomass, and richness were higher on termite mounds than adjacent savannah areas. Excluding large herbivores caused a major increase in species abundance, biomass, and richness both on savannah and termitaria. Herbaceous plant species evenness was an important determinant of the small mammal community. Small mammal biomass increased with high plant dominance, indicating that a few dominant plant species are important for biomass production of small mammals. Small mammal diversity was not related to any of the treatments, but increased with plant species evenness as well as richness. Fencing increased species dominance in the small mammal community on both savannah and termitaria, probably because competitive patterns shift from inter-guild (that is, between large and small mammals) to intra-guild (that is, between small mammals) when large mammals are excluded. The study highlights the complex interactions among large herbivores, termites, herbaceous plants, and small mammals in African savannahs. When studying the structure and function of small mammal communities it is therefore important to consider several coexisting functional groups.

The rejection or acceptance of a foreign reproductive by an alien colony may not always be as straightforward as cue recognition between worker termites. This paper aims to determine whether adoption of foreign reproductives is caused simply by lack of intraspecific aggression or is contingent on the reproductive status of the host colony. In the fungus-culturing termites, Macrotermes gilvus (Hagen) and Macrotermes carbonarius (Hagen), major workers showed low intraspecific aggression towards non-nestmates irrespective of geographic distance between source colonies. Our results indicated that workers were hardly aggressive towards non-nestmates. In royal cell-swapping experiments, both species responded in a similar way: (1) in host colonies with nymphs present, the foreign reproductives were rejected; while (2) in host colonies without nymphs the foreign reproductives were either accepted and breeding resumed or the host colonies died eventually. Workers from the host colonies preferentially maintained offspring nymphs from which adultoid replacement reproductives develop rather than accepting foreign reproductives. There is no fitness gain for the queenless workers in accepting foreign reproductives; however, there is overall benefit to the newly born population.

Landscape heterogeneity can play an important role in providing refugia and sustaining biodiversity in disturbed landscapes. Large Macrotermes (Isoptera) termite mounds in miombo woodlands form nutrient rich islands that sustain a different suite of woody plant species relative to the woodland matrix. We investigated the role of termitaria in providing habitat for cavity-using birds in miombo woodlands that had been greatly impacted by elephants and fire, by comparing the availability of habitat favored by cavity-using birds (tall trees, trees with deadwood, and cavities) on and off mounds, and then testing its effect on species richness and abundance of cavity-using birds. We surveyed 48 termitaria paired with 48 woodland matrix sites in the breeding season; and 54 matrix-termitarium pairs in the non-breeding season in Chizarira National Park, Zimbabwe. Generalized linear mixed-effects models showed that termitaria harboured significantly higher densities (ha−1) of habitat components considered important for cavity nesting birds. Density of trees >6 m in height and incidence of trees with deadwood was nearly 10 times greater on mounds than in the matrix, and the density of cavities was nine times higher on mounds compared to the matrix. A model selection procedure showed that termitaria provided refugia for cavity-using birds and contributed to the resilience of bird communities through high on-mound densities of trees with deadwood. Large termitaria thus appear to play an important role in maintaining functionally important components of the avifauna in heavily impacted Miombo woodlands.

Eusociality has evolved independently at least twice among the insects: among the Hymenoptera (ants and bees), and earlier among the Isoptera (termites). Studies of swarm intelligence, and by inference, swarm cognition, have focused largely on the bees and ants, while the termites have been relatively neglected. Yet, termites are among the world’s premier animal architects, and this betokens a sophisticated swarm intelligence capability. In this article, I review new findings on the workings of the mound of Macrotermes which clarify how these remarkable structures work, and how they come to be built. Swarm cognition in these termites is in the form of “extended” cognition, whereby the swarm’s cognitive abilities arise both from interaction amongst the individual agents within a swarm, and from the interaction of the swarm with the environment, mediated by the mound’s dynamic architecture. The latter provides large scale “cognitive maps” which enable termite swarms to assess the functional state of their structure and to guide repair efforts where necessary. The crucial role of the built environment in termite swarm cognition also points to certain “swarm cognitive disorders”, where swarms can be pushed into anomalous activities by manipulating crucial structural and functional attributes of the termite system of “extended cognition.”

This article provides a meta-analysis of quantitative data available in literature regarding the relation between termite numbers and the volume of their mounds for 24 species belonging to 13 genera. The leading question behind this analysis is: “how do the respiratory gas exchanges regulate the size of termite mounds?” This question is answered through the analysis of the log–log regression between the volume of the mound and the number of inhabitants. The most confident data support the hypothesis of a respiratory regulation that can be achieved through a relation between the termite numbers and (1) the volume of their mounds (slope of the regression near 1, Noditermes), (2) the surface of the outer walls of their mounds (slope of the regression near 0.67, Termitinae and Nasutitermes) or (3) a compromise between the surface of the outer walls of their mounds and some linear structures of their nests (slope of the regression between 0.67 and 0.33, Trinervitermes and Macrotermes). The way this is achieved is linked with the architecture of the mound. A confident relation was found between the number of individuals and the epigeal volume of their mounds for 18 species for which the most reliable data were provided. Three more accurate models are proposed for estimating the termite population based on the nest material and architecture and on the size of the termites.

The influence of processing methods of toasting and solar drying on the in vitro protein digestibility and vitamins content of edible winged termites, green grasshoppers, and brown grasshoppers consumed in Siaya, district of Kenya, was determined using standard methods. Analysis was done on fresh, toasted, toasted dried, and fresh dried insect samples. There was no significant change (p > 0.05) in protein digestibility in the termite samples, while a significant decrease (p ≤ 0.05) in the grasshopper samples was observed on toasting and drying. There was a significant reduction (p ≤ 0.05) in riboflavin content with 4.18 mg/100 g in fresh termites, 2.76 mg/100 g in toasted termites, 2.26 mg/100 g in fresh dried termites, and 1.50 mg/100 g in toasted dried termites on processing. There was also a significant reduction (p ≤ 0.05) in niacin content in the grasshoppers with 3.61 mg/100 g in fresh green grasshopper, 3.28 mg/100 g in toasted green grasshopper, 3.22 mg/100 g in fresh dried green grasshoppers, and 3.06 mg/100 g in toasted dried green grasshoppers. A significant reduction (p ≤ 0.05) in retinol content with 2.24 μg/g in fresh termites, 1.56 μg/g in toasted termites, 1.02 μg/g in toasted dried termites, and 0.98 μg/g in fresh dried termites was also reported. The processing methods of the insects affected their nutrient potential as evidenced by the changes in protein digestibility and vitamins content. Therefore, optimal processing methods need to be investigated even as we promote commercialization of these insects.

In several termite species, distinct differences in the composition of cuticular hydrocarbons among colonies correspond to high genetic divergence of mitochondrial DNA sequences. These observations suggest that hydrocarbon phenotypes represent cryptic species. Different cuticular hydrocarbon phenotypes also are found among colonies of fungus-growing termites of the genus Macrotermes. To determine if these hydrocarbon differences in Macrotermes also indicate cryptic species, we sequenced the mitochondrial CO I gene from species in West and East Africa. Among individuals of a supposed species but belonging to different cuticular hydrocarbon phenotypes, the genetic distances are much smaller than distances between species. Unlike what has been observed in other termites, Macrotermes hydrocarbon phenotypes do not represent cryptic species. Our findings suggest fundamental differences in the evolution and/or function of cuticular hydrocarbons among different termite lineages.

The diversity and abundance of epigeal termite mounds were investigated in response to controlled livestock grazing and annual prescribed fire in a Sudanian savannah-woodland in Tiogo State Forest. Sampling of termite mounds was carried out in 4×4 subplots of 0.25 ha in a split-plot experimental design during the rainy season in 2002. There were two main plots of which one was fenced to exclude livestock grazing and the second exposed to grazing. Each of the main plots included 4 subplots with annual prescribed fire since 1992 and 4 subplots without fire. Data were collected on the number and characteristics of termite mounds. A mean density of 698 mounds ha−1 was recorded. Mounds built by Trinervitermes spp. were the most abundant followed by Cubitermes spp., Macrotermes subhyalinus and M. bellicosus. The large mound-builders Macrotermes spp. dominated the community interms of basal area (96% of the total) and above-ground volume (99%). The diversity of mound types was notaffected by livestock grazing and annual early prescribed fire (P>0.05). There was no statistical effect of livestock grazing on mound density, whereas a strong depressive effect of annual fire was observed for Trinervitermes spp. mound density (P=0.012). In this ecosystem, annual prescribed fire appeared to be the major determinant for termite mound abundance.

The importance of mounds created by Macrotermes subhyalinus as safe site for tree regeneration was analysed in a savannah woodland of Burkina Faso. Plantlets (height

Chimpanzees (Pan troglodytes) are well-known to eat invertebrates, especially social insects, across Africa, but allopatric bonobos (P. paniscus) are not. Bonobo insectivory is sparsely documented and apparently sporadic. However, the availability to bonobos of social insect prey and raw materials with which to make tools to exploit them is unknown. Here, we test a set of hypotheses that relates to questions of presence, abundance, density, and distribution of taxa that Pan consume and of vegetation suitable for making extractive foraging tools. We worked at Lui Kotal, Democratic Republic of Congo, where unprovisioned bonobos live in intact forest, far from villages. We collected insect and fecal specimens, transected for prey and assessed raw materials, and monitored mounds of Macrotermes. All but 1 of the major taxa of relevant termites, ants, and (stinging) honey bees were present. The 3 main taxa of insects that chimpanzees elsewhere eat —Macrotermes (fungus-growing termites), Dorylus (Anomma; army or driver ants), and Apis (honey bees)— were abundant and widespread, and usually at densities exceeding those at well-known chimpanzee study-sites. Similarly, woody and nonwoody vegetation suitable for making fishing probes was common at mounds of Macrotermes. There is no obvious ecological reason why bonobos should not use elementary technology in extractive foraging, e.g., termite-fish, ant-fish, ant-dip, honey-dip, to obtain social insects.

The complete underground passage systems of six colonies of the termite Macrotermes carbonarius in a dry evergreen forest within the Sakaerat Environmental Research Station, northeast Thailand, were excavated. We found 4-10 main underground passages radiating out from each mound, with smoothly plastered floors (6-35 cm below the soil surface). All of the underground passages were well built (2.5-13 cm wide) and one of the main passages extended 33 m from the nest. The total length of the passages of each colony varied between 33.8 m and 112.8 m. It was demonstrated that 5 adjacent colonies of M. carbonarius generally segregated their underground passages horizontally. Vertical segregation of the passages of M. carbonarius from a subterranean nest of the neighboring species, Macrotermes annandalei was also found. In contrast to other Macrotermes species, the underground passage system of M. carbonarius only consists of major tracks and lacks a dense network of passages in the terminal part of the system. In the vicinity of their foraging sites, M. carbonarius forages in the open using pavement trackways on the ground, which are considered to be equivalent to a dense network of fine passages of other Macrotermes species.

In the galleries of Macrotermes a differentiated effect of communication was observed, by which the outward running termites could apparently distinguish between going to a feeding place or to virgin ground of exploration. The aim of this study was to investigate trail-activity in the two situations and to find out whether pheromone trails may transmit specific information about the destination of a trail.¶A new device was developed in which running termites could build up their pheromone trails in the context of their natural activity. Such trails were then bio-assayed with another independent group of termites of the same colony, also during their natural activity within an experimentally defined context of behaviour.¶In the described laboratory experiments, it was shown, that termites of Macrotermes subhyalinus, circulating between the nest and an arena filled with soil (situation of exploration), always laid pheromone trails on the substrate. If two channels coming out from the nest led into two identical arenas, an asymmetry of activity was often observed towards the two channels. This asymmetry was also found in the trail bio-assay when comparing the two trails. If one of two paths, however, led to a foraging arena, this path became significantly more active. In this situation the trail bio-assay yielded astonishing results: if the test termites were in the process of exploration, the trail, that previously led to the soil arena, appeared to be significantly more attractive than the foraging trail, even though it was less frequented during the phase before testing. On the other hand, if the test termites were part of a foraging population, the trail which led previously to the food was dominant.¶These results show that pheromone trails in Macrotermes subhyalinus may include both quantitative and qualitative components. The reaction to such information on the trail varies depending on the motivational context of the receivers.

The system of underground passages and storage pits used in foraging have been excavated in two nests of the termite Macrotermes subhyalinus in West Africa (Ivory Coast). A detailed qualitative description of the morphology and the dimensions of the passage network is given. Three types of passages could be distinguished: radial passages, big cross passages and small cross passages. These varied in their dimensions and their functional significance. Density values for the different types of passages and the storage pits in various zones of the two mounds were calculated. Density of total passages varied between 1.46 m/m2 and 1.80 m/m2 being in the order of other Macrotermes species with a comparable foraging behaviour.¶In the second part of the study intraspecific behavioural tests between pairs of colonies of M. subhyalinus and M. bellicosus were performed in neutral arenas and the zones of contact between the corresponding colonies were then excavated. Hints of agonism such as cemeteries with dry head capsules of termites, passage blockings and phenomena of horizontal or vertical passage segregation were found. Generally colonies displaying strong reaction in behavioural tests reacted in the natural context upon contact with deadly conflicts. On the other hand, colonies with a weak behavioural reaction withdrew and blocked the passages without deadly conflicts. For the first time results of laboratory bioassays were connected to unmanipulated field evidence of termite agonism.

Inhabited Macrotermes (Termitidae: Macrotermitinae) mounds in cultivated farms in the humid forest agroecological zones of southwestern Nigeria showed higher clay and silt but lower sand contents than their surrounding soils. These physical characteristics were positively correlated with those of the surrounding soils. The heights and diameters of the mounds were also positively correlated to the level of clay and silt in the surrounding soils, although the correlations were not significant (P > 0.05). Carbon and nitrogen content of 67% of the mounds was lower than that of their surrounding soils. A general increase in exchangeable bases and phosphorous contents of the mound materials compared to those of the surrounding soils was also observed. The pH of mound materials varied between 5.5 and 7.3, with 75% of the mounds having lower pH values than the surrounding soils. The implication of these results on the possible use of mound materials to increase soil fertility is discussed.

A survey for laccase, an enzyme involved in phenol oxidation, was carried out in 23 termite species from three different feeding guilds. In soil-feeding (6 species) and wood-feeding (7 species) termites, laccase activity was not detected. In contrast, all the fungus-growing termites (10 species) tested showed laccase activity. The symbiotic fungi (conidia) and fungus combs showed higher activity than the termites themselves in 6 species: Macrotermes bellicosiis, M. miilleri, Odontotermes sp., O. sp. aff. interveniens, Pseudacanthotermes spiniger and P. militaris . Fungus combs always had the highest laccase activity. The absence of laccase activity in soil-feeding and wood-feeding termites is discussed. The presence of laccase activity in both termites and Termitomyces constitutes novel information relevant to the degradation of phenols.

A sophisticated system of vibrational long distance alarm communication was found in the African fungus growing termites Macrotermes bellicosus and M. subhyalinus. When disturbed in their nests and in their extended gallery systems, soldiers produce vibrational signals by drumming their heads against the substratum. The drumming signals are trains of pulses of substrate vibrations with pulse repetition rates of 26 Hz in M. bellicosus and 13 Hz in M. subhyalinus. In both species, the carrier frequency was about 1000 Hz and the signal amplitudes about 0.5 m/s2 (acceleration, RMS). By using artificial stimuli, we examined the characteristics of the stimuli that can elicit drumming behaviour, the termites' sensitivity to substrate vibrations, their reaction time to stimuli, and their ability to discriminate vibrations of different temporal structures. We also investigated the behavioural responses of termites to drumming signals and the mechanism of long distance propagation of drumming signals through the nest and foraging sites. We found that the soldiers are extremely sensitive to vibrations, responding to vibrations with amplitudes as small as 1-2 nm by drumming themselves. This behaviour leads to the propagation of the vibrational alarm through a chain of drumming soldiers, resulting in a retreat of the termites into their nest. The termites’system of social long distance communication seems to be unique in insects.

During surveys conducted in 40 maize-cassava intercrops in the humid forest zone of southwestern Nigeria, the following termite species were identified from soil samples: Microtermes spp., Macrotermes nigeriensis (Sjostedt), Macrotermes subhyalinus (Rambur), Amitermes evuncifer (Silvestri) and Anoplotermes quietus (Fr. Muller). High incidence of Microtermes and Macrotermes spp. was observed. The population density of predominant species was generally higher in the rainy seasons than in the dry seasons, indicating the role of moisture in their spread. The soil texture of surveyed farms did not influence the presence of the subterranean species Microtermes. The level of weeds in the surveyed farms also did not affect the population density of termites. However, Microtermes population increased significantly (P < 0.05) with increase in crop residues and its presence in farms partly depended on the presence of maize in such farms. Microtermes and Macrotermes species inflicted most of the damage observed on maize crops, while that caused by Amitermes evuncifer waslow. No termite attack was observed on growing cassava during the surveys. The presence of live cassava in the intercrop did not influence damage by termites. Nasutitermes and Microcerotermes species which attack economic trees such as cocoa, citrus, oil palm, and forest trees did not attack cassava or maize.

Some physical and chemical properties of the two common termite mounds in southeastern Nigeria, Macrotermes (MM) and Cubitermes (CM) mounds, were compared and their relationships with the surrounding top and subsoils investigated. Percentage sand, silt, pH, calcium, magnesium, potassium, sodium, iron, and organic carbon were higher and clay and penetrometer resistance lower in the CM than the MM. Sand, silt, organic carbon, and calcium decreased and clay increased from the forest to the derived savanna in the CM, but no clear trend was shown with the other properties in both the CM and the MM. Most of the nutrients were higher in the CM than in the adjacent top or subsoil but the reverse was the case with the MM. More nutrients are associated with the inorganic fractions of the soil than with the organic carbon in the mounds and the soils surrounding them. The Ca:Mg ratio in the mounds and the top and subsoils adjacent to them was low for most crops but the K:Mg ratio was mostly adequate. Because of these differences in properties and sizes of the mounds, different management strategies are recommended for them and the soils around them.

In laboratory studies we analysed the reaction of aMacrotermes subhyalinus (Rambur) colony in contact with a small group of test termites placed at the head of a gallery system. As test termites we usedMacrotermes subhyalinus of the same nest,Macrotermes subhyalinus of a foreign nest and the related sympatric speciesMacrotermes bellicosus (Smeathman). Contact with an introduced group of foragers evokes a significant recruitment of workers and minor soldiers. The intensity of the response depends on the test groups we introduced. The highest recruitment results withM. bellicosus andM. subhyalinus from a foreign nest. During the recruitment the increase in the number of minor soldiers is greater than the increase in the number of workers, and as a result, the relative proportion of the soldiers in the population leaving the nest is significantly higher than before. Direct observations at the place of contact show thatM. bellicosus individuals are immediately attacked and killed. In the case ofM. subhyalinus from a foreign nest, not all individuals are killed; some are only intensively examined with the antennae or seized with the mandibles.M. subhyalinus from the same nest are rarely attacked. Mostly they are antennally inspected or enter the gallery system unhindered. The recruitment of termites from the nest is released by major workers which, after contact with the test termites, run back into the nest and provoke an alarm by tactile stimuli. On their way back into the nest the major workers, in all probability, lay a pheromone trail which leads the outgoing alarmed termites towards the place of contact.

Several mounds in western Kenya were excavated to examine their internal structure. The mounds and the soil beneath them were found to be densely packed with discrete chambers containing fungus combs. A simple system of passages opening to the exterior provided both access and ventilation to the interior of the nest. One nest was killed by fumigation and its contents extracted. The nest population was estimated to be 0.28 million adult steriles with a biomass of 462 g dry weight, and the total dry weight of fungus comb was 2.8 kg. These estimates are very low in comparison to nests of Macrotermes spp. that build mounds of comparable size. The ratio of fungus comb weight to adult biomass (6:1) is higher than that in Macrotermes spp., perhaps because the comb is constructed in a different way.

Caste-specific division of labour can be observed in extranidal activities inMacrotermes bellicosus. Food is acquired through a sequence of tasks shared between the two worker castes. During the exploration phase, a network of subterranean galleries is built outwards from the nest, almost exclusively by minor workers. The frequency of excursions made by major workers during this building period is low, but increases significantly when food is needed by the colony. After a food-source has been discovered, it is hardly exploited by the minor workers and no recruitment occurs. They continue to construct galleries, while individuals which have contact with the food show local fidelity in their building activities within the gallery nearest to the food. After a single sporadic major worker accidentally comes across a food-source, the ratio of major to minor workers continually increases. New major workers aim for the food, bite off pieces and may transfer them to the minor workers. In general, only major workers are recruited after food has been discovered, and they then orientate towards the food-source more distinctly than the minor workers.

The termite Macrotermes herus builds domed earth mounds with no external openings. The internal structure is described here. There is no specialized ventilation system in the mound, unlike those of other Macrotermes species.

Cellulose toilet roll baits were exposed in three different subhabitats at Nylsvley Reserve, northern Transvaal, and respective attacks by up to eight species of termites are described and illustrated. In broad-leaved savanna attack was principally by Microcerotermes, a slow feeder that attacked rolls throughout the year, finding about half the rolls exposed each season. In Acacia savanna attack was largely by Microtermes, a fast feeder active only at wetter times of year. In open, grassy areas there was relatively little attack, except sporadically by Macrotermes which consumed whole rolls within a day or two. Bush-fires delayed initial attack on rolls, perhaps because reduced surface litter gave less protection to soil. The amount of each roll eaten during the trials is shown in histograms; it was consistently greater in Acacia than in broad-leaved savanna. The soil-feeding termites Aganotermes and Promirotermes were attracted during the wet season to the undersides of rolls, perhaps as a source of organic-rich soil (or possibly of water).

1. Once in several days large numbers ofHospitalitermes sharpi, like other species of this oriental genus, leave their nests for a foraging trip to replenish food stores. Foraging columns are continuous, well ordered files of marching termites, up to 300 meters long and sometimes longer, stretching without interruption all the way from the nest to the grazing area on living tree bark. Topography permitting, the foraging columns follow pre-existing guide-lines, the crest-lines on the tops of sticks, roots and other elongate objects (=crest-line trailing). On vertical substrate, like cliffs or standing tree trunks, they either proceed horizontally or vertically. During any such foraging period each individual soldier and worker leaves the nest only once. 2. Homebound traffic inHospitalitermes marching columns occupies the central lanes, outbound traffic the lateral lanes. Soldiers lead the advancing column, trail the retreating column and stand on either side of every column, facing away from the column's edge. 3. The odor trails laid down by the foraging columns are bidirectional, i.e. homebound and outbound direction are indistinguishable for the termites. Misdirected homing termites restore their correct orientation after series of head-on collisions with correctly oriented companions. 4. No outside directional stimuli, in particular the directions of light and gravity, are used byHospitalitermes to make up for the directional ambivalence of the odor trail. 5. The orientation mechanism underlying crest-line trailing, the predominant type of orientation prior to the formation of an odor trail (=primary orientation), is a geoklinotaxis: the advancing termites on a crest-line, say the top of a horizontal stick, oscillate to the sides, turning back up-slope after reaching a particular angle of downward inclination. In 50% of the cases measured withHospitalitermes umbrinus, this angle is 12–13° or less from horizontal. 6. InHospitalitermes rufus, H. sharpi, andMacrotermes carbonarius, the orientation angle between the slope direction upward or downward and the direction of walking (=angle of geomenotaxis) decreases with increasing slope inclination. InMacrotermes carbonarius body weight is one factor mediating gravity perception. 7. The orientation strategy and marching column organization of the orientalHospitalitermes-species bear some striking resemblances to those of some neotropicalEciton-species (=army ants).

The flux of CH4 and CO2 from termite nests into the atmosphere has been measured in a broad-leafed-type savannah in South Africa. Measurements were carried out on nests of species of six genera, i.e., Hodotermes, Macrotermes, Odontotermes, Trinervitermes, Cubitermes, and Amitermes. The flux rates of CH4 relative to the flux rate of CO2 in terms of carbon obtained for the individual species showed ratios of 2.9 x 10 E-3, 7.0 x 10 E-4, 6.7 x 10 E-5; 8.7 x 10 E-3, 2.0 x 10 E-3 and 4.2 x 10 E-3, respectively. Using data published on the assimilation efficiencies of termites, the flux of carbon as CH4 accounts for 6.0 x 10 E-5 to 2.6 x 10 E-3 of the carbon ingested which results in a global CH4 emission by termites of 2 to 5 x 10 E12 g/yr. Methane is decomposed in the soil with average decomposition rates of 52 myg/square meter/h. The annual CH4 consumption in the tropics and subtropics is estimated to be 21 x 10 E12 g which exceeds the CH4 emission rate by termites. (IFU)

This study examines factors affecting chimpanzees' preying on termites, especially their choice of prey species. Regular surveys of a large sample of termite-mounds in the Mahale Mountains, Tanzania, confirmed that chimpanzees of B Group obtainedMacrotermes, which were relatively uncommon, by the use of fishing-tools, but ignored the much more abundantOdontotermes. This preference appeared to reflectMacrotermes' more extended swarming period, greater accessibility, larger size, and less noxious taste than the soldiers ofOdontotermes. Similar factors probably underly the chimpanzees' choice ofMacrotermes at Gombe, butPseudacanthotermes spiniger are also common there, and their absence from the diet is less easily explained. In contrast, the chimpanzees of K Group at Mahale prey mainly onP. spiniger;Macrotermes are apparently absent, andP. spiniger appear to be more abundant, accessible, and palatable than the alternativeOdontotermes.

The substrate of newly constructedMacrotermes fungus combs is inoculated from the start with viableTermitomyces conidia (asexual spores) which guarantee fast proliferation of the symbiotic fungus. The substrate is vegetable matter which has passed rapidly through the intestine of the young workers which are comb-builders and nurses. These ingest the vegetable matter which has been collected by the foragers and also feed on the nutrient enriched nodules produced by the fungus. These nodules contain the adaptive gut-resistant conidia which are mixed with the intestinal substrate on this pathway.

The onset of oviposition, incubation period, instar duration and polymorphism in the first progeny of Macrotermes michaeheni were investigated. Most incipient colonies have their first batch of eggs within the first week following establishment of the colonies. The incubation period for these eggs was 36.2 days. Three male and female larval instars, minor and major workers, and minor soldiers were found in the first progeny. Neither fourth instar larvae, which subsequently moult into major soldiers, nor nymphs, which develop into reproductives, were detected. The duration of each larval instar was determined. The longest duration was that of third instar larvae developing into both minor and major workers. The first neuter terminal castes which appeared in the colonies were minor workers, followed by major workers and, soon after, by minor soldiers in the majority of cases.

Damage to the antennae was equally common in kings and queens, and was randomly distributed. Damage to the legs was commoner in queens than in kings, and was not randomly distributed. Damage to many or all the legs of one individual may be symptomatic of degeneration due to age.

THE orientation of complex molecules in certain tissues is well known1. I have recently observed that, although the main structure of the wing of a termite (Macrotermes sp.) is isotropic, the two principal anterior veins (costal and sub-costal), running approximately parallel to the leading edge and to each other, show very marked anisotropy with the extinction direction parallel to the vein axis. These brown veins appear to contain both chitin and sclerotin.