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Termite mounds are keystone structures in African savannas, affecting multiple ecosystem processes. Despite the large size of termite mounds having the potential to modify conditions around them, patterns of mound‐induced ecosystem effects have been assumed to be isotropic, with little attention given to how effects might vary around mounds. We measured soil nitrogen content, grass species composition, and mammalian grazing on and off termite mounds in the four cardinal directions, and across wet and dry seasons at three savanna sites varying in mean annual rainfall in South Africa's Kruger National Park. Evidence of directional effects (anisotropy) on ecosystem properties around termite mounds varied with site. Grass species composition differed between north‐ and south‐facing slopes at the two drier sites where mounds were taller. However, differences in grazing extent and soil nitrogen content around mounds were only present at the intermediate rainfall site where mammalian herbivore biomass was highest, and mounds were of medium height. Our results suggest that termite mound effects display significant variation with direction, but that the emergence of directional effects is context dependent. Our results further suggest that such context‐dependent directional effects can lead to positive feedback loops between termites, abiotic conditions, and mammalian herbivores. [ABSTRACT FROM AUTHOR]

Abstract Termite mounds are keystone structures in African savannas, affecting multiple ecosystem processes. Despite the large size of termite mounds having the potential to modify conditions around them, patterns of mound‐induced ecosystem effects have been assumed to be isotropic, with little attention given to how effects might vary around mounds. We measured soil nitrogen content, grass species composition, and mammalian grazing on and off termite mounds in the four cardinal directions, and across wet and dry seasons at three savanna sites varying in mean annual rainfall in South Africa's Kruger National Park. Evidence of directional effects (anisotropy) on ecosystem properties around termite mounds varied with site. Grass species composition differed between north‐ and south‐facing slopes at the two drier sites where mounds were taller. However, differences in grazing extent and soil nitrogen content around mounds were only present at the intermediate rainfall site where mammalian herbivore biomass was highest, and mounds were of medium height. Our results suggest that termite mound effects display significant variation with direction, but that the emergence of directional effects is context dependent. Our results further suggest that such context‐dependent directional effects can lead to positive feedback loops between termites, abiotic conditions, and mammalian herbivores.

The mitogenome sequence data have been widely used in inferring the phylogeny of insects. In this study, we determined the complete mitogenome for Macrotermes sp. (Termitidae, Macrotermitinae) using next-generation sequencing. Macrotermes sp. possesses a typical insect mitogenome, displaying an identical gene order and gene content to other existing termite mitogenomes. We present the first prediction of the secondary structure of ribosomal RNA genes in termites. The rRNA secondary structures of Macrotermes sp. exhibit similarities to closely related insects and also feature distinctive characteristics in their helical structures. Together with 321 published mitogenomes of termites as ingroups and 8 cockroach mitogenomes as outgroups, we compiled the most comprehensive mitogenome sequence matrix for Termitoidae to date. Phylogenetic analyses were conducted using datasets employing different data coding strategies and various inference methods. Robust relationships were recovered at the family or subfamily level, demonstrating the utility of comprehensive mitogenome sampling in resolving termite phylogenies. The results supported the monophyly of Termitoidae, and consistent relationships within this group were observed across different analyses. Mastotermitidae was consistently recovered as the sister group to all other termite families. The families Hodotermitidae, Stolotermitidae, and Archotermopsidae formed the second diverging clade, followed by the Kalotermitidae. The Neoisoptera was consistently supported with strong node support, with Stylotermitidae being sister to the remaining families. Rhinotermitidae was found to be non-monophyletic, and Serritermitidae nested within the basal clades of Rhinotermitidae and was sister to Psammotermitinae. Overall, our phylogenetic results are largely consistent with earlier mitogenome studies. [ABSTRACT FROM AUTHOR]

The study was conducted in the laboratory to determine the termiticidal efficacy of Cymbopogoncitratus leaf extract on Termites (Macrotermes bellicosus). The experiment consisted of five treatments with three replicates. The concentrations 2g, 4g, 6g, standard control {Rambo insect powder (0.60% Permethrin) and experimental control. Termites were collected from the Termitarium found within the Akwa Ibom State University, Obio Akpa campus. Fifty Macrotermes bellicosus were introduced into Petri dishes each containing the different levels of C. citratus extract, observations were made for 30minutes, 1hour, 1hour 30 minutes, 2hours, and 3hours respectively, to test for mortality, repellency and survival duration of Macrotermes bellicosus. The results of the phytochemical screening revealed the presence of alkaloids, flavonoids, phenolics, tannins, steroids, saponins, glycosides, and citrals. Mortality test on Macrotermes bellicosus exposed to the different levels of treatments showed that mortality was extract concentration dependent. Maximum mortality was observed at standard control (insect powder), followed by the different concentrations of C. citratus extract during 3 hours exposure of termites to the extract as compared to experimental control where no mortality was recorded. There was a significant difference (p<0.05) in the number of termites that died at the different extract concentrations. The extract of C. citratus against Macrotermes bellicosus caused repellency in all the concentrations from 2g (65%), 4g (70%), 6g (85%) and standard control (100%). There was significant difference (p<0.05) in the movement of Macrotermesbellicosus from the extract baited filter paper at different concentration. Survival duration showed that all tested extract concentrations significantly (p< 0.05) reduced the survival duration of Macrotermes bellicosus. The study therefore, revealed the antitermitic activities of C. citratus which could be used as an alternative to synthetic insecticide for the control of Termites. [ABSTRACT FROM AUTHOR]

Abstract Background Termites are the most destructive pests in many agricultural and forest plantations in Uganda. Current control of termites mostly relies on chemical pesticides. However, the adverse effects of chemical insecticides necessitate the need to search for and popularize the usage of environmentally safer options. Plants represent one of the most accessible resources available for termite control by communities in Uganda. However, limited documented information exists for their contribution in the management of except through verbal sharing. This study aimed at assessing the communities’ knowledge about plants traditionally used in controlling termites among selected communities in Apac District, northern Uganda. Method An ethnobotanical survey was conducted between November 2016 and February 2017 in 12 randomly selected villages in the sub counties of Apac and Ibuje of Apac District, northern Uganda. Open-ended questionnaire interviews were used to gather ethnobotanical and sociodemographic data. A total of 381 indigenous people were interviewed [male, 281 (73.8); female, 100 (26.2)]. Data were analysed using descriptive statistics and Informant Consensus Factor (ICF), and the relative frequency of citation (RFC) was determined. Results Overall, 70.9% of the respondents were knowledgeable about plants used for control of termites. There was a significant association between respondents’ knowledge of pesticidal plants with age and gender but not with education status. A total of 11 plant species belonging to eight families were identified to be in use for control of termites in Apac. Solanaceae, Eurphorbiaceae and Asteraceae were the most represented families with two species each, while the rest of the families had only one species mentioned. According to the relative frequency of citation (RFC), Kigelia africana (Lam.) Benth. (RFC = 0.43), Vernonia amygdalina Delile (0.18) and Tithonia diversifolia (Hemsl.) A. Gray (0.10) were the most used in the control of termites in the study area. Fruits (45.9%) and leaves (29.2%) were the most used plant parts. Squeezing, crushing and chopping of the plant materials were the most popular methods of preparation and water extract was the commonest mode of formulation of plant parts. Conclusions The study has shown that rural populations of the targeted localities possess indigenous knowledge on anti-termitid plants. However, screening is urgently needed to validate their bioactivity and to determine the bioactive constituents responsible for killing the invertebrates in pest management. Furthermore, simple methods for local propagation and cultivation are needed to ensure a sustainable supply of termicidal plant biomass.

Fungus‐growing termites and their symbiotic Termitomyces fungi are critically important carbon and nutrient recyclers in arid and semiarid environments of sub‐Saharan Africa. A major proportion of plant litter produced in these ecosystems is decomposed within nest chambers of termite mounds, where temperature and humidity are kept optimal for the fungal symbionts. While fungus‐growing termites are generally believed to exploit a wide range of different plant substrates, the actual diets of most species remain elusive. We studied dietary niches of two Macrotermes species across the semiarid savanna landscape in the Tsavo Ecosystem, southern Kenya, based on carbon (C) and nitrogen (N) stable isotopes in Termitomyces fungus combs. We applied Bayesian mixing models to determine the proportion of grass and woody plant matter in the combs, these being the two major food sources available for Macrotermes species in the region. Our results showed that both termite species, and colonies cultivating different Termitomyces fungi, occupied broad and largely overlapping isotopic niches, indicating no dietary specialization. Including laser scanning derived vegetation cover estimates to the dietary mixing model revealed that the proportion of woody plant matter in fungus combs increased with increasing woody plant cover in the nest surroundings. Nitrogen content of fungus combs was positively correlated with woody plant cover around the mounds and negatively correlated with the proportion of grass matter in the comb. Considering the high N demand of large Macrotermes colonies, woody plant matter seems to thus represent a more profitable food source than grass. As grass is also utilized by grazing mammals, and the availability of grass matter typically fluctuates over the year, mixed woodland‐grasslands and bushlands seem to represent more favorable habitats for large Macrotermes colonies than open grasslands. [ABSTRACT FROM AUTHOR]

Macrotermes barneyi, widely distributed in southern China, is the major fungus-growing termite in the subfamily Macrotermitinae. It has no flagellated protists in the guts. Here, we report occurrence of gregarine, a protozoan parasite in the digestive tract of M. barneyi. The general morphology and ultrastructure of the gregarine gamonts and syzygies by light micrograph and scanning electron micrograph are presented. SSU rDNA sequence analysis showed that the termite gregarine has the highest identity (90.10%) to that of Gregarina blattarum from cockroaches. Phylogenetic analysis based on the SSU rDNA sequences from diverse insect eugregarines indicated that the gregarine from M. barneyi is phylogenetically close to G. blattarus, L. erratica and G. tropica from Gregarinidae and Leidyanidae families, and may represent a novel species. This study expands our knowledge about the diversity of terrestrial eugregarines parasitizing in termites. [ABSTRACT FROM AUTHOR]

The use of chemical insecticides has had many adverse effects. This study reports a novel perspective on the application of insect-based compounds to repel and eradicate other insects in a controlled environment. In this work, defense fluid was shown to be a repellent and insecticide against termites and cockroaches and was analyzed using gas chromatography-mass spectrometry (GC–MS). Globitermes sulphureus extract at 20 mg/ml showed the highest repellency for seven days against Macrotermes gilvus and for thirty days against Periplaneta americana. In terms of toxicity, G. sulphureus extract had a low LC50 compared to M. carbonarius extract against M. gilvus. Gas chromatography–mass spectrometry analysis of the M. carbonarius extract indicated the presence of six insecticidal and two repellent compounds in the extract, whereas the G. sulphureus extract contained five insecticidal and three repellent compounds. The most obvious finding was that G. sulphureus defense fluid had higher potential as a natural repellent and termiticide than the M. carbonarius extract. Both defense fluids can play a role as alternatives in the search for new, sustainable, natural repellents and termiticides. Our results demonstrate the potential use of termite defense fluid for pest management, providing repellent and insecticidal activities comparable to those of other green repellent and termiticidal commercial products. [ABSTRACT FROM AUTHOR]

This study investigated the effect of land‐use on density and distribution patterns of termite mounds. A total area of 12 ha was investigated using four 1 ha plots from each of three land‐use types (mango orchards, maize fields and communal rangelands). A total of 297 mounds from four termite species were recorded. Plotted GIS coordinates for each mound in ArcMap showed a random distribution pattern in all land‐use types. The mean number of mounds per hectare was significantly higher (p < 0.001) in communal rangelands (52.5 ± 1.21), than in maize fields (14.75 ± 3.15) and mango orchards (7.5 ± 0.87), and dominated by small‐sized mounds of Trinervitermes sp. Few mounds of Odontotermes sp. were found. Mounds of the edible termites, Macrotermes natalensis and M. falciger, were found in all land‐use types, with the highest density for both species being in maize fields. Although the mound height for both species was similar, mound circumference for M. falciger was significantly larger (p < 0.001) which may limit land available for agricultural use. Density of mounds was influenced by land‐use which may lead to changes in termite ecosystem functioning and availability of termites as a free source of protein. [ABSTRACT FROM AUTHOR]

A computational model has been developed to predict the role of environment in the forms and functions of termite mounds. The proposed model considers the most relevant forces involved in the heat transfer process of termite mounds, while also reflecting their gas-exchange function. The method adopts a system configuration procedure to determine thermally optimized mound structures. The model successfully predicts the main architectural characteristics of typical Macrotermes michaelseni mounds for the environmental conditions they live in. The results indicate that the mound superstructure and internal condition strongly depend on the combined effect of environmental forces. It is noted that mounds being exposed to higher solar irradiances develop intricate lateral channels, inside, and taller and more pronounced spire tilt towards the Sun, outside. It is also found that the mounds' spire tilt angle depends on the geographical location, following the local average solar zenith angle for strong irradiances. Although wind does not influence the overall over-ground mound shape, it significantly affects the mound internal condition. The results of this study resonate with what is seen in nature. The proposed approach provides a broader view of the factors that are effective in the form and function of a naturally made structure.

This study aimed to promote the use of termites as feed in traditional poultry farming by developing sustainable and inexpensive termite trapping techniques. Various tests were carried out in Burkina Faso to improve the traditional technique of trapping termites of the genus Macrotermes using a reversed container filled with organic matters. We studied the effect of containers’ types, substrates, habitats, harvesting times, duration of trap deposition, and season on the quantity of termites trapped. Calabashes and terra cotta pots trapped more termites than iron boxes, but calabashes were quickly destroyed by termites. The quantity of termites harvested increased proportionally with the volume of the pot and was higher in a cultivated habitat than in a forest, despite the higher number of termite mounds in the forest. The quantity of termites harvested was lowest in the cold-dry season and highest during the rainy season, however, sizeable amounts of termites were collected throughout the year. Among six substrates and mixtures of substrates tested, maize cobs trapped the highest number of termites and cow dung the lowest. The best time of harvest varied among seasons and, if substrates are abundant, it is more efficient to empty the containers on a daily basis.

Fungus-farming termites host gut microbial communities that contribute to the pre-digestion of plant biomass for manuring the fungal mutualist, and potentially to the production of defensive compounds that suppress antagonists. Termite colonies are characterized by complex division of labor and differences in diet between termite size (minor and major) and morphological (worker and soldier) castes, and this extends to the composition of their gut microbial communities. We hypothesized that gut metabolomes should mirror these differences and tested this through untargeted LC-MS/MS analyses of three South African species of fungus-farming termites. We found distinct metabolomes between species and across castes, especially between soldiers and workers. Primary metabolites dominate the metabolomes and the high number of overlapping features with the mutualistic fungus and plant material show distinct impacts of diet and the environment. The identification of a few bioactive compounds of likely microbial origin underlines the potential for compound discovery among the many unannotated features. Our untargeted approach provides a first glimpse into the complex gut metabolomes and our dereplication suggests the presence of bioactive compounds with potential defensive roles to be targeted in future studies.

Termites in the genus Macrotermes construct large-scale soil mounds above their nests. The classic explanation for how termites coordinate their labour to build the mound, based on a putative cement pheromone, has recently been called into question. Here, we present evidence foran alternate interpretation based on sensing humidity. The high humidity characteristic of the mound’s internal environment extends a short distance into the low-humidity external world, in a ‘bubble’ that can be disrupted by external factors like wind. Termites transport more soil mass into on-mound reservoirs when shielded from water loss through evaporation, and into experimental arenas when relative humidity is held at a high value. These results suggest that the interface between internal and external conditions may serve as a template for mound expansion, with workers moving freely within a zone of high humidity and depositing soil at its edge. Such deposition of additional moist soil will increase local humidity, in afeedback loop allowing the ‘interior’ zone to progress further outward and lead to mound expansion. [ABSTRACT FROM AUTHOR]

Macrotermes bellicosus, though a beneficial termite species causes serious damage to wood and wood products, fabrics and many agricultural crops and ornamental trees. This study was conducted to assess the potentials of essential oils of the leaves of Chromolaena odorata and roots of Uvaria chamae in the control of M. bellicosus. The repellency, knockdown and insecticidal effects of the oils to M. bellicosus were tested using the filter paper and cotton ball impregnation technique. Each test oil (0.05, 0.075 and 0.10 ml) was separately used in the repellency assay, for an exposure period of 30 and 60 minutes. For the knockdown and toxicity test, termites were exposed to 0.05, 0.075, 0.10, 0.125 and 0.15 ml of each oil for an exposure period of 60 minutes and 6 hours, respectively. Each test and control (untreated) group had three replicates and in each experiment twenty active workers of M. bellicosus were exposed. Repellency results were somewhat irregular and oil volume and exposure, time independent. Knockdown effect of 56.67 and 86.67% were observed for C. odorata and U. chamae oils (0.15ml), respectively at the 60th minute. Contact toxicity test with 0.15 ml of the oils resulted in 100% and 86.67% mortalities for U. chamae and C. odorata, respectively. No knockdown or mortalities were observed in the controls. The difference between the repellency of both oils at 30 and 60 minutes was not significant (p>0.05; p= 0.842 and 0.212 respectively), whereas for knockdown and insecticidal effects of both oils the difference was significant Q3(p<0.05; p= 0.000 and 0.001 respectively). Essential oils of C. odorata and U. chamae are potential agents for the control of M. bellicosus. [ABSTRACT FROM AUTHOR]

Termites are widely used as a food resource, particularly in Africa and Asia. Markets for insects as food are also expanding worldwide. To inform the development of insect-based foods, we analysed selected minerals (Fe-Mn-Zn-Cu-Mg) in wild-harvested and commercially available termites. Mineral values were compared to selected commercially available insects. Alate termites, of the genera Macrotermes and Odontotermes, showed remarkably high manganese (Mn) content (292–515 mg/100 gdw), roughly 50–100 times the concentrations detected in other insects. Other mineral elements occur at moderate concentrations in all insects examined. On further examination, the Mn is located primarily in the abdomens of the Macrotermes subhyalinus; with scanning electron microscopy revealing small spherical structures highly enriched for Mn. We identify the fungus comb, of Macrotermes subhyanus, as a potential biological source of the high Mn concentrations. Consuming even small quantities of termite alates could exceed current upper recommended intakes for Mn in both adults and children. Given the widespread use of termites as food, a better understanding the sources, distribution and bio-availability of these high Mn concentrations in termite alates is needed. [ABSTRACT FROM AUTHOR]

Background Large and complex mounds built by termites of the genus Macrotermes characterize many dry African landscapes, including the savannas, bushlands, and dry forests of the Tsavo Ecosystem in southern Kenya. The termites live in obligate symbiosis with filamentous fungi of the genus Termitomyces. The insects collect dead plant material from their environment and deposit it into their nests where indigestible cell wall compounds are effectively decomposed by the fungus. Above-ground mounds are built to enhance nest ventilation and to maintain nest interior microclimates favorable for fungal growth. Objectives In Tsavo Ecosystem two Macrotermes species associate with three different Termitomyces symbionts, always with a monoculture of one fungal species within each termite nest. As mound architecture differs considerably both between and within termite species we explored potential relationships between nest thermoregulatory strategies and species identity of fungal symbionts. Methods External dimensions were measured from 164 Macrotermes mounds and the cultivated Termitomyces species were identified by sequencing internal transcribed spacer (ITS) region of ribosomal DNA. We also recorded the annual temperature regimes of several termite mounds to determine relations between mound architecture and nest temperatures during different seasons. Results Mound architecture had a major effect on nest temperatures. Relatively cool temperatures were always recorded from large mounds with open ventilation systems, while the internal temperatures of mounds with closed ventilation systems and small mounds with open ventilation systems were consistently higher. The distribution of the three fungal symbionts in different mounds was not random, with one fungal species confined to “hot nests.” Conclusions Our results indicate that different Termitomyces species have different temperature requirements, and that one of the cultivated species is relatively intolerant of low temperatures. The dominant Macrotermes species in our study area can clearly modify its mound architecture to meet the thermal requirements of several different symbionts. However, a treacherous balance seems to exist between symbiont identity and mound architecture, as the maintenance of the thermophilic fungal species obviously requires reduced mound architecture that, in turn, leads to inadequate gas exchange. Hence, our study concludes that while the limited ventilation capacity of small mounds sets strict limits to insect colony growth, in this case, improving nest ventilation would invariable lead to excessively low nest temperatures, with negative consequences to the symbiotic fungus.

'Brains' may be considered to be computation engines, with neurons and synapses analogized to electronic components wired into networks that process information, learn and evolve. Alternatively, 'brains' are cognitive systems, which contain elements of intentionality, purposefulness and creativity that do not fit comfortably into a brain-as-computer metaphor. I address the question of how we may think most constructively about brains in their various forms—solid, liquid or fluid—and whether there is a coherent theory that unites them all. In this essay, I explore cognitive systems in the context of new understanding of life's distinctive nature, in particular the core concept of homeostasis, and how this new understanding lays a sound conceptual foundation for an expansive theory of brains. This article is part of the theme issue 'Liquid brains, solid brains: How distributed cognitive architectures process information'. [ABSTRACT FROM AUTHOR]

Termite colonies construct towering, complex mounds, in a classic example of distributed agents coordinating their activity via interaction with a shared environment. The traditional explanation for how this coordination occurs focuses on the idea of a 'cement pheromone', a chemical signal left with deposited soil that triggers further deposition. Recent research has called this idea into question, pointing to a more complicated behavioural response to cues perceived with multiple senses. In this work, we explored the role of topological cues in affecting early construction activity in Macrotermes. We created artificial surfaces with a known range of curvatures, coated them with nest soil, placed groups of major workers on them and evaluated soil displacement as a function of location at the end of 1 h. Each point on the surface has a given curvature, inclination and absolute height; to disambiguate these factors, we conducted experiments with the surface in different orientations. Soil displacement activity is consistently correlated with surface curvature, and not with inclination nor height. Early exploration activity is also correlated with curvature, to a lesser degree. Topographical cues provide a long-term physical memory of building activity in a manner that ephemeral pheromone labelling cannot. Elucidating the roles of these and other cues for group coordination may help provide organizing principles for swarm robotics and other artificial systems. This article is part of the theme issue 'Liquid brains, solid brains: How distributed cognitive architectures process information'. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Decomposition is important for nutrient cycling and the dynamics of soil organic matter. The factors that influence local decomposition rates in savannas dominated by Macrotermes mounds remain uncertain. Here, we experimentally assessed the effects of macro- and micro-detritivores, active and inactive mounds, and vegetation cover on wood decomposition rates for eight common woody plant species in Lake Mburo National Park, in Uganda. Five pairs of Macrotermes mounds, one active and one inactive per pair, were selected. Each mound provided two sample locations, one, the most shaded (with canopy cover), and one, the most open (without canopy cover) edge of mound. In addition, for each mound pair, one additional sample location was located off-mound, in an open level area between the mounds. After one, three, and 12 months, protected (wrapped in 1-mm mesh fiber-glass excluding macrodetritivores) and unprotected wood samples from each location were retrieved, brushed clean, oven-dried, and weighed. After 12 months, mean percentage mass loss was four times higher for unprotected than protected wood samples across all species located on mound sites (when decomposition in shaded and open microhabitats was combined). Mean percentage mass loss across all species combined was 1.2 times higher on active than inactive mounds. Across all mounds, decomposition was on average 1.1 times more rapid in the shaded than open mound parts. These differences were more pronounced on inactive mounds (1.3 times more rapid in the shaded than open parts). Percentage mass loss was markedly lower off-mound (12.6 ± 0.8%) than on active (25.9 ± 1.5%) or inactive mounds (19.7 ± 1.2%). Proportional mass loss for unprotected wood decreased with increasing wood density, but proportional mass loss of protected wood samples was not detectably influenced by wood density. Our study highlights the strong and locally contingent influence of termite mounds, termite activity, vegetation, and their interactions on wood decomposition rates within a savanna landscape. Furthermore, variation in per-species wood decomposition rates, including the negative correlation with wood density, depends on accessibility to macrodetritivores. [ABSTRACT FROM AUTHOR]

Background: Large and complex mounds built by termites of the genus Macrotermes characterize many dry African landscapes, including the savannas, bushlands, and dry forests of the Tsavo Ecosystem in southern Kenya. The termites live in obligate symbiosis with filamentous fungi of the genus Termitomyces. The insects collect dead plant material from their environment and deposit it into their nests where indigestible cell wall compounds are effectively decomposed by the fungus. Above-ground mounds are built to enhance nest ventilation and to maintain nest interior microclimates favorable for fungal growth. Objectives: In Tsavo Ecosystem two Macrotermes species associate with three different Termitomyces symbionts, always with a monoculture of one fungal species within each termite nest. As mound architecture differs considerably both between and within termite species we explored potential relationships between nest thermoregulatory strategies and species identity of fungal symbionts. Methods: External dimensions were measured from 164 Macrotermes mounds and the cultivated Termitomyces species were identified by sequencing internal transcribed spacer (ITS) region of ribosomal DNA. We also recorded the annual temperature regimes of several termite mounds to determine relations between mound architecture and nest temperatures during different seasons. Results: Mound architecture had a major effect on nest temperatures. Relatively cool temperatures were always recorded from large mounds with open ventilation systems, while the internal temperatures of mounds with closed ventilation systems and small mounds with open ventilation systems were consistently higher. The distribution of the three fungal symbionts in different mounds was not random, with one fungal species confined to "hot nests." Conclusions: Our results indicate that different Termitomyces species have different temperature requirements, and that one of the cultivated species is relatively intolerant of low temperatures. The dominant Macrotermes species in our study area can clearly modify its mound architecture to meet the thermal requirements of several different symbionts. However, a treacherous balance seems to exist between symbiont identity and mound architecture, as the maintenance of the thermophilic fungal species obviously requires reduced mound architecture that, in turn, leads to inadequate gas exchange. Hence, our study concludes that while the limited ventilation capacity of small mounds sets strict limits to insect colony growth, in this case, improving nest ventilation would invariable lead to excessively low nest temperatures, with negative consequences to the symbiotic fungus. [ABSTRACT FROM AUTHOR]

The efficacy of Jatropha curcas in the management of wood termites, (Macrotermes bellicosus) was carried out in the Teaching and Research Farm of the Department of Forestry and Wildlife Resources Management. University of Calabar. The experiment consisted of 5 levels of J. curcas oil (0, 0.5, 1.0, 1.5 and 2.0) and a corresponding quantity in powder, replicated 4 times and arranged in Randomized Completely Block Design (RCBD). Each concentration was tested on 20 unsexed adult wood termite placed in grave yard of 8cm x 8cm. Data on mortality rate was taken at 12 hourly up to 72 hours. The result from the experiment showed that J. curcas oil was significantly efficacious compared with J. curcas powder both in the field and in the laboratory. It was observed that there was progressive increase in mortality rate due to increased concentration and time duration. The management of termite using J. curcas should be encouraged due to its environmental friendliness and should also be incorporated into integrated pest management (IPM). [ABSTRACT FROM AUTHOR]

Humans pose a major threat to many species through land-use change in virtually every habitat. However, the extent of this threat is largely unknown for invertebrates due to challenges with investigating their distributions at large scales. This knowledge gap is particularly troublesome for soil macrofauna because of the critical roles many of these organisms perform as ecosystem engineers. We used a combination of high-resolution airborne Light Detection and Ranging and deep learning models to map the distribution of the ecologically important termite genus Macrotermes across a South African savanna land-use gradient, quantifying the effects of land-use change on patterns of mound densities, heights and spatial patterning. Despite significant anthropogenic alteration to landscapes, termite mounds persisted and shared a number of similarities to mounds in untransformed areas. Mean mound height was not substantially reduced in transformed landscapes, and over-dispersion of mounds at localized scales was conserved. However, mound densities were partially reduced, and height distributions in transformed areas differed to those in protected areas. Our findings suggest that mound-building termites persist even in areas of relatively high human disturbance, but also highlight important differences in termite distributions that could lead to reductions in ecosystem services provided by termites in human-modified landscapes. The persistence of at least half of mounds in human-modified landscapes could serve as starting points for savanna restoration.

Fungus-growing termites rely on mutualistic fungi of the genus Termitomyces and gut microbes for plant biomass degradation. Due to a certain degree of symbiont complementarity, this tripartite symbiosis has evolved as a complex bioreactor, enabling decomposition of nearly any plant polymer, likely contributing to the success of the termites as one of the main plant decomposers in the Old World. In this study, we evaluated which plant polymers are decomposed and which enzymes are active during the decomposition process in two major genera of fungus-growing termites. We found a diversity of active enzymes at different stages of decomposition and a consistent decrease in plant components during the decomposition process. Furthermore, our findings are consistent with the hypothesis that termites transport enzymes from the older mature parts of the fungus comb through young worker guts to freshly inoculated plant substrate. However, preliminary fungal RNA sequencing (RNA-seq) analyses suggest that this likely transport is supplemented with enzymes produced in situ. Our findings support that the maintenance of an external fungus comb, inoculated with an optimal mixture of plant material, fungal spores, and enzymes, is likely the key to the extraordinarily efficient plant decomposition in fungus-growing termites. [ABSTRACT FROM AUTHOR]

Termite mounds perform important roles in savanna ecosystems, generating heterogeneity and influencing ecosystem processes across multiple trophic levels. However, the influence the environment and neighboring termite colonies have on mound spatial patterning and structure is poorly understood, despite the profound implications such dynamics can have on ecosystems. To better understand these drivers, we mapped the spatial distribution and size of active and inactive Macrotermes mounds in eight 1-km2 plots on contrasting geologies, nutrient-rich granite and nutrient-poor basalt, in a semi-arid Zimbabwean savanna. Although mound density was not significantly different between basalt (5.5 mounds/ha) and granite (6.1 mounds/ha), termite mound structural attributes and spatial distribution patterns varied greatly between geologies. Mound size distributions differed between the geologies and mounds were 2.6 times taller and 3.9 times wider and had 15 times greater lateral surface area on granite. Subsequently, 6% of the total landscape was covered by mounds on granite compared with only 0.4% on basalt. On granite, large mounds exhibited significant over-dispersion at scales below 30 m, signifying density-dependent thinning. Furthermore, small mounds were clustered around large mounds, likely a result of the budding of new colonies comprising fully fledged castes less vulnerable to competition. In contrast, random patterning was evident on comparably homogenous basalt. Our results demonstrate the powerful influence geological substrate has on mound spatial patterning and structure, suggesting that the importance of termite mounds for ecosystem functioning is more pronounced on nutrient-poor granitic substrates than basalts because of the pronounced over-dispersion, which maximizes mound production per unit area, and much larger mound sizes here. [ABSTRACT FROM AUTHOR]

The study aimed at nutritional characterization of commonly consumed insects in Langosub region, northern Uganda. Proximate composition, mineral and fatty acid profile of Syntermes soldiers, Macrotermes bellicosus and Brachytrupes spp were determined using standard analytical methods. Analysis of Variance (ANOVA) was performed and means were separated using Least Significant Difference (LSD) test at 5% (P=0.05). Nutrient contents of Syntermes soldiers, Macrotermes bellicosus and Brachytrupes spp were: 64.72, 40.72, 65.35% protein; 4.99, 44.84, 11.76% fat; 23.03, 8.38, 16.87% dietary fibre and; 4.19, 5.69, 4.88% ash, respectively. Energy content was 502.86, 696.10, 536.42 kcal/100 g while protein digestibility was 31.39, 44.39, 50.22%, respectively. Essential minerals were abundant with 897.15, 676.96, 877.26 mg/100 g potassium; 32.50, 42.71, 33.60 mg/100 g iron and; 17.64, 16.90, 23.02 mg/100 g zinc, respectively. Levels of essential fatty acids were appreciable with: 16.74, 8.92, and 22.14% Linoleic acid and 2.88, 0.63, and 2.55% Linolenic acid, respectively. Oleic acid was the most abundant at 37.64, 47.73 and 38.27%. While the ratio of total polyunsaturated fatty acid to total saturated fatty acids were; 1.32, 0.24, and 0.71 respectively. Consumption of these insects could contribute to the dietary intakes of the essential nutrients. [ABSTRACT FROM AUTHOR]

Vast areas of the African savanna landscapes are characterized by tree-covered Macrotermes termite mounds embedded within a relatively open savanna matrix. In concert with termites, large herbivores are important determinants of savanna woody vegetation cover. The relative cover of woody species has considerable effects on savanna function. Despite the potentially important ecological relationships between termite mounds, woody plants, large herbivores, and birds, these associations have previously received surprisingly little attention. We experimentally studied the effects of termites and large herbivores on the avian community in Lake Mburo National Park, Uganda, where woody vegetation is essentially limited to termite mounds. Our experiment comprised of four treatments in nine replicates; unfenced termite mounds, fenced mounds (excluding large mammals), unfenced adjacent savanna, and fenced savanna. We recorded species identity, abundance, and behavior of all birds observed on these plots over a two-month period, from late dry until wet season. Birds used termite mounds almost exclusively, with only 3.5% of observations occurring in the treeless intermound savanna matrix. Mean abundance and species richness of birds doubled on fenced (large herbivores excluded) compared to unfenced mounds. Feeding behavior increased when large mammals were excluded from mounds, both in absolute number of observed individuals, and relative to other behaviors. This study documents the fundamental positive impact of Macrotermes termites on bird abundance and diversity in an African savanna. Birds play crucial functional roles in savanna ecosystems, for example, by dispersing fruits or regulating herbivorous insect populations. Thus, the role of birds in savanna dynamics depends on the distribution and abundance of termite mounds. [ABSTRACT FROM AUTHOR]

In order to assess the environmental indicator potential of wasp nests and termite mounds, the palynomorph content of three randomly selected Macrotermes sp. mounds (termitaria) and two Vespula vulgaris nests collected on the University of Lagos campus were examined. Palynological analysis showed the presence of 298 well-preserved palynomorphs showing characteristic morphological features. The recovered palynomorphs included pollen, pteridophyte spores and fungal spores, along with insect parts (106), diatoms (7) and a protist (1). The pollen assemblage of termite mounds comprised 78 pollen and pteridophyte spores, with Poaceae and Arecaceae pollen as dominants. In the wasp nest the pollen assemblage comprised 28 pollen and spore taxa, with Poaceae and Arecaceae pollen also dominant. Both mounds and nests had, besides diatoms, six pollen and spore taxa: Poaceae, Amaranthaceae, Pteridophyte spores, Arecaceae, Raffia sp. and Rhizophora sp. Vegetational grouping of the recovered pollen and spores indicated five phytoecological groups: secondary forest, mangrove swamp forest, freshwater, open vegetation and Poaceae. In statistical analyses, termite mounds had a higher species richness value (2.08 as compared to 1.99 from the wasp nests), while the wasp nests had a higher species diversity value (0.997 as compared to 0.845 from the termite mounds). Pollen analyses of the termite mounds and wasp nests suggest that both could be useful tools in environmental studies. This is the first attempt to evaluate the potential of termite mounds and wasps nest as natural pollen accumulators in Nigeria. The results suggest new possibilities for the use of the pollen records preserved in termite mounds and wasp nests for environmental studies. [ABSTRACT FROM AUTHOR]

Dispersal of soil-dwelling organisms via the repeatedly exposed Sunda shelf through much of the Pleistocene in Southeast Asia has not been studied extensively, especially for invertebrates. Here we investigated the phylogeography of an endemic termite species, Macrotermes gilvus (Hagen), to elucidate the spatiotemporal dynamics of dispersal routes of terrestrial fauna in Pleistocene Southeast Asia. We sampled 213 termite colonies from 66 localities throughout the region. Independently inherited microsatellites and mtDNA markers were used to infer the phylogeographic framework of M. gilvus. Discrete phylogeographic analysis and molecular dating based on fossil calibration were used to infer the dynamics of M. gilvus dispersal in time and space across Southeast Asia. We found that the termite dispersal events were consistently dated within the Pleistocene time frame. The dispersal pattern was multidirectional, radiating eastwards and southwards out of Indochina, which was identified as the origin for dispersal events. We found no direct dispersal events between Sumatra and Borneo despite the presence of a terrestrial connection between them during the Pleistocene. Instead, central Java served as an important link allowing termite colonies to be established in Borneo and Sumatra. Our findings support the hypothesis of a north-south dispersal corridor in Southeast Asia and suggest the presence of alternative dispersal routes across Sundaland during the Pleistocene. For the first time, we also propose that a west-east dispersal through over-water rafting likely occurred across the Pleistocene South China Sea. We found at least two independent entry routes for terrestrial species to infiltrate Sumatra and Borneo at different times. [ABSTRACT FROM AUTHOR]

Termites host a gut microbiota of diverse and essential symbionts that enable specialization on dead plant material; an abundant, but nutritionally imbalanced food source. To supplement the severe shortage of dietary nitrogen (N), some termite species make use of diazotrophic bacteria to fix atmospheric nitrogen (N2). Fungus-growing termites (subfamily Macrotermitinae) host a fungal exosymbiont (genus Termitomyces) that provides digestive services and the main food source for the termites. This has been thought to obviate the need for N2-fixation by bacterial symbionts. Here we challenge this notion by performing acetylene reduction assays of live colony material to show that N2 fixation is present in two major genera (Macrotermes and Odontotermes) of fungus-growing termites. We compare and discuss fixation rates in relation to those obtained from other termites, and suggest avenues of research that may lead to a better understanding of N2 fixation in fungus-growing and other termites.

Abstract Termite mounds have recently been shown to protect against drought by providing refuges for plants and foci for revegetation, but whether mounds modulate temperature remains untested. Organisms tend to experience climate at finer scales than those captured by models predicting how distributions alter with global change, so microclimates represent important “climate refuges.” Using data we collected from African savanna sites, generalized linear mixed‐effects models and linear quantile regression analysis confirm for the first time that the woody species associated with large termite mounds establish microclimates that are significantly cooler than surrounding savannas, a cooling effect that is even greater at warmer extremes. As air temperatures approached 40°C, a cooling effect of up to 4°C occurred, representing a doubling from that observed at 34°C. African savannas encompass 10 million km2, and much of this harbors evenly dispersed termitaria. The temperature‐modulating effect of mounds facilitates agricultural and conservation decision‐making as global change begins to impact the integrity of both human well‐being and ecological processes.

Competition is a fundamental process in ecology and helps to determine dominance hierarchies. Competition and dominance hierarchies have been little investigated in wood-eating termites, despite the necessary traits of similar resources, and showing spatial and temporal overlap. Competition and dominance between five species of wood-eating termites found in Huangzhou, China, was investigated in three laboratory experiments of aggression and detection, plus a year-long field survey of termite foraging activity. Dominance depended on body size, with largest species winning overwhelmingly in paired contests with equal numbers of individuals, although the advantage was reduced in paired competitions with equal biomass. The termites could detect different species from used filter papers, as larger species searched through paper used by smaller species, and smaller species avoided papers used by larger species. The largest species maintained activity all year, but in low abundance, whereas the second largest species increased activity in summer, and the smallest species increased their activity in winter. The termite species displayed a dominance hierarchy based on fighting ability, with a temporal change in foraging to avoid larger, more dominant species. The low abundance of the largest species, here Macrotermes barneyi, may be a function of human disturbance, which allows subordinate species to increase. Thus, competitive release may explain the increase in abundance of pest species, such as Coptotermes formosanus, in highly modified areas, such as urban systems.

The aim of the study was to gather information on the use of termites by farmers as feed for indigenous poultry in Ghana and factors affecting its use. We conducted surveys in four regions in Ghana to collect information, by the administration of questionnaires, on the use of termites as poultry feed, termite species collected, species not used and collection methods. Samples of termite species mentioned were collected and identified to the genus level. Twenty-three percent and 19% of farmers mentioned that termites are always or often used to feed poultry whereas 11% never use termites. A binomial regression analysis showed that their utilization was affected by region, sex, education, farm size and income. Termites collected belonged to eight genera, the main ones being Macrotermes, Trinervitermes and Odontotermes. Five collection methods are used to obtain termites and involve either breaking mounds or using containers as traps. Collection methods vary with species and region and the abundance of termite genera varies with season. Farmers identified some species as poisonous to poultry. Termites are important in indigenous poultry production because they are a readily available protein source for local farmers. However, better collection methods need to be developed to aid their optimal use.

Termites host a gut microbiota of diverse and essential symbionts that enable specialization on dead plant material; an abundant, but nutritionally imbalanced food source. To supplement the severe shortage of dietary nitrogen (N), some termite species make use of diazotrophic bacteria to fix atmospheric nitrogen (N2). Fungus-growing termites (subfamily Macrotermitinae) host a fungal exosymbiont (genus Termitomyces) that provides digestive services and the main food source for the termites. This has been thought to obviate the need for N2-fixation by bacterial symbionts. Here, we challenge this notion by performing acetylene reduction assays of live colony material to show that N2 fixation is present in two major genera (Macrotermes and Odontotermes) of fungus-growing termites. We compare and discuss fixation rates in relation to those obtained from other termites, and suggest avenues of research that may lead to a better understanding of N2 fixation in fungus-growing and other termites. [ABSTRACT FROM AUTHOR]

Termite mounds have recently been shown to protect against drought by providing refuges for plants and foci for revegetation, but whether mounds modulate temperature remains untested. Organisms tend to experience climate at finer scales than those captured by models predicting how distributions alter with global change, so microclimates represent important "climate refuges." Using data we collected from African savanna sites, generalized linear mixed-effects models and linear quantile regression analysis confirm for the first time that the woody species associated with large termite mounds establish microclimates that are significantly cooler than surrounding savannas, a cooling effect that is even greater at warmer extremes. As air temperatures approached 40°C, a cooling effect of up to 4°C occurred, representing a doubling from that observed at 34°C. African savannas encompass 10 million km2, and much of this harbors evenly dispersed termitaria. The temperature-modulating effect of mounds facilitates agricultural and conservation decision-making as global change begins to impact the integrity of both human well-being and ecological processes. [ABSTRACT FROM AUTHOR]

African savannas are highly seasonal with a diverse array of both mammalian and invertebrate herbivores, yet herbivory studies have focused almost exclusively on mammals. We conducted a 2-yr exclosure experiment in South Africa's Kruger National Park to measure the relative impact of these two groups of herbivores on grass removal at both highly productive patches (termite mounds) and in the less productive savanna matrix. Invertebrate and mammalian herbivory was greater on termite mounds, but the relative importance of each group changed over time. Mammalian offtake was higher than invertebrates in the dry season, but can be eclipsed by invertebrates during the wet season when this group is more active. Our results demonstrate that invertebrates play a substantial role in savanna herbivory and should not be disregarded in attempts to understand the impacts of herbivory on ecosystems. [ABSTRACT FROM AUTHOR]