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.

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.

Termites, particularly the mound building, fungus growing Macrotermitinae, reach densities of up to 400 termites m−2 in soils of dry tropical Africa. The influence of Macrotermi tinae in increasing certain soil nutrients in mounds compared to adjacent soils has been documented, but the links between litter harvesting by termites, soil fertility, and global C cycling have not been explored. This study reviews the evidence from soil science, ecology and atmos pheric chemistry and generates hypotheses to explain the role of termites in dry tropical eco systems. It is suggested that termite activity exhaustively partitions litterfall among adjacent com peting colonies, where it is so thoroughly decomposed that little or no organic C is incorporated into the soils. Associated N, P, and cations build up in the mounds, but C apparently is emitted as CO2 and CH4 from the mounds. While not adequate to calculate nutrient fluxes through termites, the data available support the argument that termites contribute significantly to atmospheric fluxes of CO2 and CH4. Moreover, they suggest a coupling of regional soil forming processes and the global C budget.

Termites are dominant invertebrates in tropical soils (Wood & Sands 1978) and are important mediators of decomposition in terrestrial ecosystems (Abe & Matsumoto 1979, Lawton et al. 1996, Lee & Wood 1971, Matsumoto & Abe 1979, Wood & Sands 1978, Yamada et al. 2005). Furthermore, these processes, such as carbon mineralization and nitrogen fixation, are dependent on the species assemblage structure of the termite community (Lawton et al. 1996, Yamada et al. 2005, 2006). Feeding habits of termites reflect their metabolic processes. The three major isopteran groups – wood-feeders, fungus-growers (fungus-growing wood/litter feeders), soil-feeders – appear to play very different roles in the decomposition process (Tayasu et al. 1997, Wood 1976, Wood & Sands 1978, Yamada et al. 2005). Consequently, the relative abundance of each feeding group provides useful information on the function of the termite assemblage in an ecosystem.

Termite workers, Macrotermes subhyalinus (Rambur), produced two cellulase-free xylanases, namely Xyl A and Xyl B. DEAE-Sepharose CL-6B, Sephacryl S-200 HR, CM-Sepharose CL-6B and Phenyl-Sepharose CL-4B chromatographies purified these enzymes. They exhibited molecular masses of 63–66.1 (Xyl A) and 60.7–62.4 (Xyl B) kDa. Both enzymes appeared to be endo-xylanases, which produced oligomers of xylose from xylan and did not hydrolyse them to xylose. They had different optimum pH (pH 4.6–5.0 for Xyl A and pH 5.0 for Xyl B) and different optimum temperatures (60 °C for Xyl A and 55 °C for Xyl B). However, they had the same pH stability (4.0–5.6). Both enzymes were stable at 50 °C for more than 4 h. At a pH ranging from 4.6–5.0 and 60 °C, Xyl A and Xyl B possessed the half-life of 115 and 60 min, respectively. The xylanase activities were stimulated by Na+, Mn2+ and dithiol-reducing agents and were sensitive to Cu2+ and detergent agents. Their enzymatic activity was slightly reduced by the presence of urea at 1% (w/v) concentration. The two enzymes could be used in the presence of organic solvents such as acetone (up to 10% v/v) without loss of activity.

Termite foraging was monitored with cellulose baits in both the wet and dry season in the semi-arid Okavango Delta region of northern Botswana. Seven wood-feeding species were found. Fungus-growing termites dominated the assemblage in all plots, and four species (Macrotermes michaelseni, Odontotermes sp. A, Allodontermes sp. and Microtermes sp.) were found in most. Foraging by smaller-bodied Allodontermes sp. and Microtermes sp. was largely confined to the wet season. Foraging by M. michaelseni and Odontotermes sp. A was more constant, but showed a general peak in the early dry season (May and June), likely due to nutrient and energy demands associated with alate production. Despite extensive overlap in distributions of these species, co-occurrences on baits were significantly less frequent than expected by chance. In addition, incidence in a plot of Allodontermes sp. and Microtermes sp. was negatively correlated in the wet season, as was that of M. michaelseni and Odontotermes sp. A in the dry season. Differences in body size, life history, and nest structure produce temporal and spatial heterogeneity in the foraging and distribution patterns of termites, and therefore suggest that consideration of community composition can improve prediction of the influence of termite assemblages on decomposition.

At intervals of 2 months over 1 year, 64 royal cells were removed from mounds of Macrotermes michaelseni to find out whether a new royal pair was produced. In five mounds replacement reproductives were found. Young reproductives from incipient laboratory colonies were never accepted as replacements if they were introduced after the removal of the primary reproductives. One out of 10 royal pairs was accepted if the royal cell was introduced immediately after removal of the original one, and three out of 10 survived if the royal cell was introduced 1 week after the removal of the original one.

Replacement reproductives were only produced when nymphs or alates were in the nest at the time the primary reproductives were removed. It was not possible to find out at what time after the removal a new royal pair was accepted but measurements of the replacement queens showed that they can become fully physogastric within 7 months.