Nutritional ecology of ropical ecosystems like Neotropical savannas, which are of high conservation concern, is understudied. Sodium is essential for heterotrophs but availability often falls short relative to plant consumer requirements. Savanna plant consumers like ants and termites should be sodium-limited due to high temperatures, nutrient-poor soils, and lack of oceanic sodium deposition. We tested the hypothesis that Neotropical savanna ants and termites are sodium-limited. Termites were tested by supplementing 0.25 m2 plots with H2O (control), 0.1%, 0.5%, or 1.0% NaCl and measuring termite presence and artificial substrate mass loss after 1 week. Ants were tested by collecting ants that recruited to H2O (control), 0.1%, 0.5%, and 1.0% NaCl and 1.0%, 10%, and 20% sugar baits on paired diurnal–nocturnal transects. Termites were 16 times more likely to occur on 1% NaCl than H2O plots and wood-feeding termites were most frequent. However, the decomposition rate did not differ among treatments. Ant bait use increased with increasing NaCl concentration and 1% NaCl usage was similar to sugar bait usage. Ants were 3.7 times more active nocturnally than diurnally, but contrary to predictions bait type (water, sugar or NaCl) usage did not differ between day and night. Together, these results provide strong evidence of sodium limitation in Neotropical savannas.

Termites are a significant pest of buildings, agriculture, and trees, and are mainly controlled by baiting. However, baiting systems are available for only lower termites (Rhinotermitidae) not for higher termites (Termitidae). Termite foraging behavior associated with baiting systems varies among species and families, and plays a significant role in baiting success. Here, foraging behavior of Odontotermes obesus (Blattodea: Termitidae: Macrotermitinae), a fungus-growing higher termite, was investigated relative to three bait-station sizes (small, medium, and large) containing different quantities of food. Significantly more workers recruited to large stations (470/station) compared to medium (246/station) and small (124/station) stations. Abundance of O. obesus in large and medium stations significantly positively correlated with relative humidity whereas negative but non-significant correlations were observed with temperature in large and medium stations. Total and continuous contacts with the stations increased with time and were greater in large stations. Station abandonment due to disturbance was significantly less in large stations (3%) followed by medium (9%) and small stations (20%). Our results suggest that large stations (≈8 litres volume) work best for population management of O. obesus and other related fungus-growing higher termites.

The subterranean termite Reticulitermes grassei Clément causes lesions in the trunk of Quercus suber L. by constructing feeding galleries, but no information is available regarding other Quercus species from the Mediterranean region. This work aimed to study the suitability of the other main oak species of Mediterranean forests as a food resource for R. grassei. Two experiments, choice and non-choice feeding, were conducted lasting for 15, 30, and 45 days each. In the non-choice experiment, termites were offered one of the following food types: Quercus suber, Quercus ilex L., Quercus faginea Lam, cork or Pinus pinea L., which was considered the control. The choice feeding experiment used all the same food types listed above, supplied simultaneously in the same container. Food selection was examined by analysing the relationships over time between surviving termites and food consumption. The results indicated that R. grassei could be considered a generalist species, as it consumed the cork and wood of all oak species, as well as displaying a clear preference for soft wood (pine). Correlation analysis indicated that consumption was not dependent on wood density. Survival of R. grassei was influenced by the time of exposure to different oak species, but a high survival rate was maintained over time in the pine treatment (upper 70% in the three experiments). Given these results, it can be concluded that all the oak species are a suitable food source for R. grassei.

Fungus-growing termites (Macrotermitinae) are important pests in tropical countries. They are difficult to control with existing baiting methods, as chitin synthesis inhibitors are not effectual as active ingredients. We tested two neurotoxins, fipronil and imidacloprid, as potential bait active ingredients against Macrotermes gilvus (Hagen) in Singapore. In laboratory bioassays, M. gilvus showed no preference for doses of 0–64 ppm fipronil, or for doses of 0–250 ppm imidacloprid, indicating no repellence. We tested each insecticide in toilet paper as a bait matrix in a field experiment. After 28 days, termites had eaten 5–13% of the fipronil treated toilet paper, abandoned bait and monitoring stations, contacted no new stations, and repaired poorly their experimentally damaged mounds. Termites ate no imidacloprid treated toilet paper, abandoned bait stations although contacted new stations, and repaired fully their damaged mounds. Termites ate 60–70% of the control toilet paper, remained in bait stations, and fully repaired damaged mounds. After 56 days, all five fipronil colonies were eliminated, whereas all of the imidacloprid and control colonies were healthy. The results suggest that fipronil could be an effective active ingredient in bait systems for fungus-growing termites in tropical countries.

Litter-feeding termites influence key aspects of the structure and functioning of semi-arid ecosystems around the world by altering nutrient and material fluxes, affecting primary production, foodweb dynamics and modifying vegetation composition. Understanding these complex effects depends on quantifying spatial heterogeneity in termite foraging activities, yet such information is scarce for semi-arid savannas. Here, the amount of litter that was removed from 800 litterbags in eight plots (100 litterbags per plot) was measured in Hluhluwe–iMfolozi Park (HiP) South Africa. These data were used to quantify variation in litter removal at two spatial scales: the local scale (within 450-m2 plots) and the landscape scale (among sites separated by 8–25 km). Subsequently, we attempted to understand the possible determinants of termites’ foraging patterns by testing various ecological correlates, such as plant biomass and bare ground at small scales and rainfall and fences that excluded large mammalian herbivores at larger scales. No strong predictors for heterogeneity in termite foraging intensity were found at the local scale. At the landscape scale termite consumption depended on an interaction between rainfall and the presence of large mammalian herbivores: litter removal by termites was greater in the presence of large herbivores at the drier sites but lower in the presence of large herbivores at the wetter sites. The effect of herbivores on termite foraging intensity may indicate a switch between termites and large herbivore facilitation and competition across a productivity gradient. In general, litter removal decreased with increasing mean annual rainfall, which is in contrast to current understanding of termite consumption across rainfall and productivity gradients. These results generate novel insights into termite ecology and interactions among consumers of vastly different body sizes across spatial scales.

The lower termite, Coptotermes gestroi (Isoptera: Rhinotermitidae), is originally from Southeast Asia and has become a pest in Brazil. The main goal of this study was to survey C. gestroi transcriptome composition. To accomplish this, we sequenced and analyzed 3003 expressed sequence tags (ESTs) isolated from libraries of worker heads. After assembly, 695 uniESTs were obtained from which 349 have similarity with known sequences. Comparison with insect genomes demonstrated similarity, primarily with genes from Apis mellifera (28%), Tribolium castaneum (28%) and Aedes aegypti (10%). Notably, we identified two endogenous cellulases in the sequences, which may be of interest for biotechnological applications. The results presented in this work represent the first genomic study of the Asian subterranean termite, Coptotermes gestroi.

Previous studies in Sundaland (Borneo, Sumatra, Java and Peninsular Malaysia) have shown that termite assemblages in natural forests have a characteristic structure. These typical forest assemblages contain many soil-feeding species. However, this study investigated four natural forest sites in Borneo with depauperate termite assemblages, and compared their soils with soils from four other sites that have typical termite assemblages. In contrast to the typical assemblages, the four depauperate assemblages all have low species density (<35%), low relative abundance (<30%), a virtual absence of soil-feeders, significantly fewer wood-feeders, and a near-absence of species of Rhinotermitidae, Amitermes-group, Termes-group, Pericapritermes-group and Oriensubulitermes-group. The depauperate sites are on ultramafic-derived soils and have significantly higher concentrations of calcium, magnesium, nickel, chromium, cobalt, copper and zinc compared with the non-ultramafic soils at sites with typical assemblages. In addition, soil pH at the depauperate sites is significantly higher (>pH 5.4) compared with soils at the typical sites (which are all below pH 4.7). Possible mechanisms to explain the depauperate termite assemblages on ultramafic soils include metal toxicity, high pH disrupting gut physiology, and microbial interactions with metals.

The change of mound structure of the fungus growing termite, Macrotermes gilvus, which has no clear air passage system in the mound, was examined in relation to the mound growth in a rubber plantation of southern Thailand. The nest proper consisted of the hive with a royal chamber and nursery, and diffused chambers with fungus combs. The location of the hive became higher with the growth of the mound. Therefore, colonies with a very large mound utilize only the upper mound part and this may be due to the lack of air passage systems in this species. A colony with a very large mound is not in reality commensurately large in colony size and this may be the reason why the density of huge mounds of M. gilvus in Thailand is much higher than that of Macrotermes in Africa.

Intuitively, termites would seem to be a very suitable group to illustrate effects of ecosystem fragmentation. Being detritivores, they do not control directly the rate at which their resources are available, nor do they restrict the ability of the resources to regenerate. Consequently, termites do not mask the ecosystem depletion caused by fragmentation. With this in mind, we compared the communities of termites in undisturbed Amazonian forest with those of two isolated fragments nearby, aiming to show that the differences observed may have resulted from habitat fragmentation. Dissimilarities between communities in the undisturbed forest suggest natural patchiness in their distribution, which could lead to misinterpretation of the effects of fragmentation. Continuous forest had higher species richness and fewer rare species than the fragments. Guild structure in the forest was biased towards soil-feeding termites, which are subterranean and soft bodied, and therefore more sensitive to variation in microclimate. In the fragments, litterfeeders and species intermediate between soil-feeding and wood-feeding types were numerically more important. Habitats in the forest were more equally used than in the fragments, suggesting habitat unsuitability increased with fragmentation. It is suggested that the community composition of the fragments is a result of the intrinsic patchiness of the original forest and deterministic and stochastic extinctions caused by fragmentation. The need for manipulative experiments to test such ideas is discussed.

Estimates were made of the populations of seven nests of Macrotermes jeanneli of different sizes in Kenya. Caste and instar composition were examined, and relationships of these to the dimensions of the mound were investigated. Survival of nests of different sizes was followed over four years.

Descriptions of the fine scale distribution of organisms have frequently been used to investigate various ecological phenomena. Unfortunately, the most widely used spatial analysis techniques are based on single index statistics, which convey only minimal information about the biological processes underlying the studied distributions. Such statistics cannot detect changes in pattern over different scales, and cannot identify some types of distribution. Additionally, both the use of such statistics on the distribution of individuals which have a non-negligible size, and the frequent failure to use an edge correction for points close to the boundaries of a sampled area, have led to the over-reporting of ‘spaced out’ (‘regular’) distributions. Using two spatial distributions recently analysed with a single index statistic (termite mounds, and earthmounds created by termites), I illustrate the benefits gained from using the spatial functions K(t), G(y) and F(x) to analyse both ‘point events’ and events which have a non-negligible size. These functions are considerably more informative about the nature of a spatial pattern and offer wide scope for the fitting of spatial models to biological distributions.

The abundance and diversity of soil macrofauna were assessed in a range of vegetation types in northern Botswana. Hand-sorting of soil was used to extract all fauna greater than 2 mm body length from sandy soils in both the dry season (June) and towards the end of the single rainy season (February). Abundance varied significantly between samples from within a sampling location, within a vegetation type and occasionally between seasons. Greater densities were found in wet season samples from locations within closed canopy woodland except where permanent water was a significant feature of the habitat. Overall abundance was comparable to published estimates from more moist tropical and temperate habitats suggesting an important role for soil macrofauna in semi-arid systems. Ordinal level diversity also varied significantly within vegetation types and with season.

The food habits of four hypogeous Macrotermitinae species were studied using stable carbon isotope analysis in several biotopes of a humid savanna of West Africa (Lamto, Côte d'Ivoire). The proportion of woody and herbaceous material in the diet of the different species was determined by measuring the 13C natural abundance in the fungus comb. The diet varied with season and biotope, especially tree density. The results confirm the flexibility of the food habits of the fungus-growing termites as a consequence of their exosymbiosis with the fungus Termitomyces sp.

Why is the ground brown, when detritivores and decomposers have the numbers and ability to speed up the turnover of dark-coloured soil organic carbon? We consider this soil analogue to the ‘green world’ hypothesis measuring in the field how fast termites occupied cellulosic baits of varying quantity and quality and how predation risks by ants affect such encounters. Single baits with ants were occupied by termites later than triple baits without ants, implying that termites may spend longer searching for suitable food than feeding on it, thereby delaying decomposition rates of both chosen and neglected items. Because termites' feeding speeds up dissimilation of polymers by decomposers, such results may imply that bottom-up and top-down forces, ultimately, impair carbon processing and release from soil. We argue that the ground is brown partly because of delays imposed upon termites' use of resources by bottom-up and top-down forces.

The mark–recapture technique is currently being used by many termite researchers. Here it's two uses are explained and disentangled. Use 1 is mapping the geographical location of the colony and use 2 is estimating the number of termites in the colony. Use 2 is controversial because the accuracy of the estimates has been widely questioned. In this article, it is explained that use 1 is not controversial and that use 1 (not use 2) is the criterion that is currently being used for evaluating the efficacy of termite baits.

The species present, and the frequencies and intensities of termite attack on 600 paper baits exposed at the soil surface were compared over three seasonal exposures and between two savanna sites of contrasting vegetation structure in northern Australia. Eleven species were recorded, with Microcerotermes nervosus and Schedorhinotermes actuosus comprising 43% and 27% of collections respectively. The most commonly sampled species nest underground or build epigeal mounds and are known to feed on sound and decaying wood. Changes in species dominance occurred between seasons and the two forest types. In both vegetation types, the number of species active and the frequency of attack increased with the duration of bait exposure and decreased in the order: transitional > wet > dry. Bait consumption was greater in the site with higher canopy cover, and did not differ significantly between seasons. No direct relationships were noted between rainfall recorded at the sites and species richness, frequency and intensity of attack on baits. We recommend exposure of paper baits for at least 2 mo during the transitional period as the optimal protocol for sampling at the time of greatest activity and diversity of those species within the guild of wood-feeding species regularly attracted to paper baits.

The termite species Macrotermes bellicosus has a vast geographical distribution, which can produce genetic divergence in populations that evolve in its different environments. Experiments carried out on digestive oxidases in two populations of M. bellicosus originating from Chad and from Côte d'lvoire showed differences in the rate of their enzymatic activities. Populations from Côte d'lvoire showed significantly higher degradation activity against fresh vegetal matter than populations from Chad.

Termites were surveyed at an altitude of 1000 m in Maliau Basin, Sabah (Borneo), in two primary forest habitats: lower montane forest and stunted facies of upper montane forest. Soil, wood, litter, termite nests, and arboreal microhabitats up to a height of 2 m above ground were sampled using a belt transect protocol. Two transects were run in each forest type. The upper montane forest transects collected 11 and 13 species, compared with 15 and 19 in the lower montane forest transects. With the addition of species records from casual sampling (conducted with roughly equal effort in each forest type), totals of 18 species were found in the upper montane forest, and 34 species in the lower montane forest. Similar species richness and relative abundance of wood-feeding termites were found in both forest types. However, the lower montane forest had greater richness and relative abundance of species that feed on soil and extremely decayed soil-like wood. This difference is attributed mainly to (i) the well developed, organic-rich soils of the lower montane forest being more suitable for soil-dwelling and mound-building termites compared with the upper montane forest which has sandy soils with a thick covering of peat, and (ii) the low-stature and open canopy of the upper montane forest creates microclimatic conditions which are adverse for soil-feeding termites compared with the high, closed canopy in the lower montane forest. As expected, comparisons with similar studies in lowland forests in Southeast Asia confirmed that the upland forests are relatively depauperate.

Termite damage to annual crops on smallscale farms was surveyed in eight areas in southern Malawi during 1989/90 to 1991/92. The most frequently grown crop was maize, followed by pigeonpeas, Phaseolus beans, cotton, cowpea and groundnuts. Twenty-seven species of termites were found attacking crops. The most numerous and widely distributed were several species of the Macrotermitinae, including Ancistrotermes latinotus, four species of Macrotermes, four species of Microtermes, three species of Odontotermes and Pseudacanthotermes militaris. All species damaged maize but only a few damaged bambara, cassava and banana. The damage appeared to be more frequent in dry areas than in wet ones.

Studies were carried out from 1990 to 1993 to identify termite species associated with cocoa and coffee in Ghana. Ten genera/species, belonging to the families Termitidae and Rhinotermitidae, were recorded from cocoa and coffee trees aged from 6 to 36 months. The commonest was Ancistrotermes sp., followed by Amitermes sp., Microtermes subhyalinus, Microtermes sp. and Nasutitermes sp. Others were Macrotermes bellicosus, Pseudacanthotermes sp., Cubitermes sp., Schedorhinotermes putorius and Coptotermes sp. All species except M. bellicosus, Pseudacanthotermes sp. and Cubitermes sp. caused damage to cocoa and/or coffee. The shade tree, Gliricidia sp. was attacked by Pseudacanthotermes sp. whereas Macrotermes bellicosus and Cubitermes sp. were harmless. The relative abundance of these termites is discussed.