Macrotermes Carbonarius Research Articles

Seasonal dynamic of termite foraging (isoptera) in Cat Tien National Park (South Viet Nam)

Foraging activity of five termite species, namely Macrotermes carbonarius (Hagen), M. gilvus (Hagen), M. malaccensis (Haviland), Hypotermes obscuriceps (Wasmann), Hospitalitermes bicolor (Haviland), was studied in Cat Tien National Park for two years with monthly performed route counting of open forages. Chosen model species differed in ecological preferences, life history and the nesting type. Termites community showed foraging activity all round the year. Foraging activity despite the original hypothesis did not correlate significantly with precipitation level and soil temperature measured monthly. Most of species increased foraging activity in dry months, but decreased it in months with heavy rains. In rainy season, most of species demonstrated not only night time foraging activity typical for Asian termites, but also were actively foraging during the daytime. During the dry season, foraging activity happened only in night time. Termite species showed different strategies and adaptations to abiotic conditions, which allow the community to maintain decomposing activity all round the year.

Virome of Three Termite Species from Southern Vietnam.

Modern metagenomic approaches enable the effective discovery of novel viruses in previously unexplored organisms. Termites are significant ecosystem converters and influencers. As with the majority of tropical forest insects, termites are studied insufficiently, and termite virome remains especially understudied. Here, we studied the virome of lichenophagous and mycophagous termites (Hospitalitermes bicolor, Macrotermes carbonarius and Odontotermes wallonensis) collected in the Cat Tien National Park (Vietnam). We assembled four full genomes of novel viruses related to Solemoviridae, Lispiviridae, Polycipiviridae and Kolmioviridae. We also found several contigs with relation to Chuviridae and Deltaflexiviridae that did not correspond to complete virus genomes. All the novel viruses clustered phylogenetically with previously identified viruses of the termites. Deltaflexi-like contigs were identified in the fungi-cultivating M. carbonarius and showed homology with viruses recently discovered in the edible basidiomycete mushrooms.

Effect of Fungus-Growing Termite on Soil CO2 Emission at Termitaria Scale in Dry Evergreen Forest, Thailand

Termites are one of the major contributors to high spatial variability in soil respiration. Although epigeal termite mounds are considered as a point of high CO2 effluxes, the patterns of mound CO2 effluxes are different, especially the mound of fungus-growing termites in a tropical forest. This study quantified the effects of a fungus-growing termite (Macrotermes carbonarius) associated with soil CO2 emission by considering their nesting pattern in dry evergreen forest, Thailand. A total of six mounds of M. carbonarius were measured for CO2 efflux rates on their mounds and surrounding soils in dry and wet seasons. Also, measurement points were investigated for the active underground passages at the top 10% of among efflux rates. The mean rate of CO2 emission from termitaria of M. carbonarius was 7.66 µmol CO2/m2/s, consisting of 2.94 and 9.11 µmol CO2/m2/s from their above mound and underground passages (the rate reached up to 50.00 µmol CO2/m2/s), respectively. While the CO2 emission rate from the surrounding soil alone was 6.86 µmol CO2/m2/s. The results showed that the termitaria of M. carbonarius contributed 8.4% to soil respiration at the termitaria scale. The study suggests that fungus-growing termites cause a local and strong variation in soil respiration through underground passages radiating out from the mounds in dry evergreen forest.

Evaluation of the chemical defense fluids of Macrotermes carbonarius and Globitermes sulphureus as possible household repellents and insecticides

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.

A study of a termite chemical defense fluid compound of Macrotermes carbonarius

Termite caste consists of reproductive individuals, worker, and soldier. Soldiers defend their colony by physical and chemical means. For Macrotermes carbonarius, they use mandibles as their physical defense and defense fluid for chemical defense. Their defense fluid plays a vital role to defend their caste from any harm from another insect such as ants. This can be related to the fact that M. carbonarius is an urban pest that has many threats to their colony. However, less study had been focused on their defense fluid composition and how the compounds function. This study was carried out to determine the compound present in the defense fluid of M. carbonarius. The methods used in this study were thin layer chromatography (TLC) and gas chromatography mass spectrometry (GCMS). TLC detection indicated presence of three unknown compounds and one important compound. GCMS analysis had confirmed the compound as lauric acid methyl esther that was obtained from the TLC. This information would contribute to fill up the research gap and assist in better understanding the compound composition found in M. carbonarius defense fluid to protect their colony, an update on the defense fluid research since 1979 by Prestwich.

Bait station preferences in two Macrotermes species

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.

Molecular Cloning of Five β-Glucosidases from Four Species of Higher Termites (Blattodea: Termitidae)

Abstract Cellulose is the most abundant polymer in the biosphere, and termites are one of the most important metazoan cellulose processors. Termites are a rich source of digestive enzymes such as endo- β-1,4-glucanases, β-glucosidases, xylanases, amylases, pectinases, and laccases, regardless of whether they are termite derived or of microbiotic origin. Molecular identification of the termite's digestive enzyme is a critical initial step toward using termites as bioresources for industrial applications. Here, we report five β-glucosidase sequences obtained from four species of higher termites (Anoplotermes schwarzi Banks, Macrotermes carbonarius (Hagen), Rhynchotermes bulbinasus Scheffrahn, Sphaerotermes sphaerothorax (Sjoestedt)) with differing nutritional biologies. The deduced amino acid sequences indicated that they were most similar to β-glucosidases in the glycosyl hydrolase family 1 (GHF1). All complete coding sequences are 490 amino acids long and contain conserved motifs involved in substrate binding and catalysis. Each sequence was also predicted to be glycosylated at two sites.

Does lack of intraspecific aggression or absence of nymphs determine acceptance of foreign reproductives in Macrotermes?

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.

Subterranean termite open-air foraging and tolerance to desiccation: Comparative water relation of two sympatric Macrotermes spp. (Blattodea: Termitidae)

The foraging patterns of termites are strongly related to physiological limits in overcoming desiccation stress. In this study, we examined moisture preferences and physiological characteristics of Macrotermes carbonarius (Hagen) and M. gilvus (Hagen) as both exhibit conspicuous patterns of foraging activity. Despite both species showing no significant differences in calculated cuticular permeability, and percentage of total body water, they differed greatly in rate of water loss and surface area to volume ratio. For example, M. carbonarius which had a lower surface area to volume ratio (29.26–53.66) showed lower rate of water loss and percentage of total body water loss. This also resulted in higher LT 50 when exposed to extreme conditions (≈ 2% RH). However, contrasting observations were made in M. gilvus that has smaller size with higher surface area to volume ratio of 40.28–69.75. It is likely that the standard equation for calculating insect surface areas is inadequate for these termite species. The trend was further supported by the result of a moisture preference bioassay that indicated M. carbonarius had a broader range of moisture preference (between 5% and 20%) than M. gilvus which had a relatively narrow moisture preference (only 20%). These results explain why M. carbonarius can tolerate desiccation stress for a longer period foraging above-ground in the open air; while M. gilvus only forages below ground or concealed within foraging mud tubes.

The Parasitoid,Verticia fasciventrisCauses Morphological and Behavioral Changes in Infected Soldiers of the Fungus-Growing Termite,Macrotermes carbonarius

The larval parasitoid Verticia fasciventris Malloch (Diptera: Calliphoridae) develops in the head of soldiers of the fungus-growing termite Macrotermes carbonarius (Hagen) (Isoptera: Termitidae). Morphological and behavioral changes in the host were evaluated and the termite castes and stages that were parasitized were identified. The larval emergence process is also described and possible mechanisms for the parasitoid fly's entry into the host body are discussed based on qualitative observations. Only a single larva per host was found. The mature larva pupated outside the host's body by exiting between the abdominal cerci. Parasitized soldiers possess a short and square-shaped head capsule, a pair of notably short mandibles, and a pair of 18-segmented antennae. Although parasitized soldiers were statistically less aggressive than healthy soldiers (P < 0.05), they expressed varying levels of aggression. Both minor and major soldiers can be parasitized and based on evidence from presoldiers, parasitization may begin during the precursor stages of soldiers. However, the stage at which parasitism first occurs has not been determined.

Termites (Isoptera) in forest ecosystems of Cat Tien National Park (Southern Vietnam)

The species composition and termite community populations were studied and the total land termites biomass was estimated in five forest habitats of Cat Tien National Park, Southern Vietnam. Twenty-four species of two families, Rhinotermitidae (1 species) and Termitidae (23 species), the predominant representatives of the subfamily Macrotermitinae, were found in mounds and in soil samples. On the test plots the density of termite mounds averaged 68 per hectare, primarily the mounds of three Macrotermes species. Destructive sampling allowed estimation of the caste composition and total community biomass based on six termite mounds of the prevailing species (Globitermes sulphureus, Microcerotermes burmanicus, Macrotermes carbonarius, M. gilvus, M. malaccensis, and Hypotermes obscuriceps). The total number of termites in the nests ranged from 65 000 to 3 150 000 individuals with the total biomass ranging from 185 to 2440 g live weight. The total abundance of nesting Macrotermes species alone could conservatively be estimated as 2.5 million individuals and 20.5 kg live weight per hectare. The number of soil- and litter-feeding termites averaged for the test plots was estimated at about 60 ind./m2. Four species dominating on the test plots (M. carbonarius, M. gilvus, M. malaccensis, and H. obscuriceps) belong to active tree litter feeders.

Polyhydroxyalkanoate (PHA) accumulating bacteria from the gut of higher termite Macrotermes carbonarius (Blattodea: Termitidae)

The continuous quest for bacterial strains capable of accumulating polyhydroxyalkanoate (PHA) utilizing cheaper and renewable carbon source prompted us to explore newer and diverse environments like the gut of termites. Among the bacterial strains isolated from the gut of higher termite Macrotermes carbonarius, three strains were found to accumulate PHA, as observed by microscopic studies and PHA production experiments. Among them, strain MC1 with rapid growth and higher PHA accumulation was selected for further studies. API kit-50 CHB and 16S rRNA gene sequence analysis results indicated the strain to have 99% homology with Bacillus megaterium and Bacillus flexus. Bacillus sp. MC1 was able to accumulate PHA during the growth phase utilizing different carbon sources like glucose, fructose, sodium acetate, sodium valerate and 1,4-butanediol. Gas chromatography analysis of the polymer has shown it to be basically composed of poly (3-hydroxybutyrate) (PHB). Growth associated PHB biosynthesis was best in the presence of sodium acetate with 39 wt% after 16 h of cultivation. Though previous studies provided evidence confirming the presence of PHA producing bacteria in termite gut, isolation and characterization of these strains in pure culture has not been documented yet. Presence of other morphotypes in the termite gut with PHA like granular inclusions was evident from the transmission electron microscopy studies. This is a novel report and shows the feasibility of using potent strains capable of utilizing lignocellulosic degradation products as a renewable carbon source for the production of PHA in the future.

Flight Activity of Two Sympatric Termite Species,Macrotermes gilvusandMacrotermes carbonarius(Termitidae: Macrotermitinae)

Flight activities of two sympatric termite species, Macrotermes gilvus (Hagen) and Macrotermes carbonarius (Hagen), were studied in Penang Island, Malaysia. Herein, we present the first documentation of chronological reproductive isolation of M. gilvus and M. carbonarius. Flights of M. gilvus were recorded over a remarkably long 7-mo period from March to September, whereas swarming of M. carbonarius took place from November to January. Swarming events of M. gilvus and M. carbonarius occurred under atmospheric pressures of 1,005-1,011 and 1,006-1,010 hPa, respectively. Most flights of M. gilvus occurred on days with rain, whereas M. carbonarius avoided rain. Flight activity of M. gilvus was correlated significantly with atmospheric pressure and rainfall. The threshold temperature and relative humidity of M. gilvus flights were between 23 and 26 degrees C and 83 and 98% RH, respectively; M. carbonarius swarmed between 25 and 30 degrees C and 72 and 83% RH, respectively. The flight activity of M. gilvus concentrated in the warmer and humid months with a monthly total rainfall of 228 mm. Both species swarmed at distinct times of day during the limited field observations: Flights of M. gilvus began between 0300 and 0430 hours (light intensity <1 Lx), and flights of M. carbonarius lasted for only 4-10 min between 1900 and 1910 hours (at dusk; light intensity: 20-200 Lx). Windless conditions were preferred for the flights of both species.

Developmental Stages and Castes of Two Sympatric Subterranean Termites Macrotermes gilvus and Macrotermes carbonarius (Blattodea: Termitidae)

Abstract The developmental stages and castes of two sympatric subterranean termites, Macro-termes gilvus (Hagen) and Macrotermes carbonarius (Hagen) (Blattodea: Termitidae) were studied and biometric descriptors of each caste were developed for the identification of both species. Biometric descriptors revealed five well-defined groups of larval castes. After sex determination, three larval instars were detected in the development of minor and major worker castes. The first larval instars consist of both males and females which are homogenous in size. Size sexual dimorphism, in which females are smaller than males, occurs in the second larval instars, third larval instars, and worker castes. Minor and major soldiers are female sterile castes. Pictorial evidence of the fourth larval instar of M. carbonarius is presented herein; the individuals closely resemble minor workers but are poorly pigmented and have a distended abdomen, future presoldier-like mandibles, and a meso- and metanotum. In reproductive caste development, nymphs (derived from the first larval instars) undergo five moults from first to fifth instars before becoming winged termites.

Occurrence of poly(hydroxyalkanoate) in the gut homogenate of a phylogenetically higher termite: Macrotermes carbonarius

Gas chromatography analysis of a phylogenetically higher termite-gut homogenate detected the presence of trace amounts of poly(3-hydroxybutyrate) (PHB), a prokaryotic storage material. In addition, the gut homogenate smear, stained with Nile blue A, also suggested the presence of PHB-like granules. Chloroform extracts of both soldier and worker classes of this termite were obtained for further spectroscopic analysis. FTIR, 1H NMR, and 2D 1H-1H NMR analyses confirmed the presence of PHB in both the chloroform extracts. This showed for the first time the occurrence of bacteria capable of accumulating PHB in the termite gut. The results indicated that the physiological environment in the termite gut is suitable for the colonization by PHB-producing bacteria and is probably rich in organic carbon sources, which can be readily assimilated and stored as PHB.Key words: Macrotermes carbonarius, poly(hydroxyalkanoate), PHB, termite

Estimation of the longevity of C in terrestrial detrital food webs using radiocarbon (14C): how old are diets in termites?

Summary We propose that diets of consumers in a food web have various ages, where age is defined as the time elapsed since carbon (C) in the diet was fixed from atmospheric CO2 by primary producers. To examine the diet ages for primary consumers in a detrital food web, we measured the radiocarbon (14C) content of termites collected in Thailand in 1998 and 2004. Diet ages were estimated by comparing the 14C content of samples with records of atmospheric 14CO2, which doubled in the early 1960s as a result of nuclear weapons tests and decreased after the nuclear test ban treaty. For comparison, we measured the 14C content of bees as primary consumers in a grazing web at the same study site. Stable carbon and nitrogen (N) isotope ratios were also analysed. The 14C contents of the same species of termites decreased during the sampling interval, indicating that they used organic matter produced after the peak in atmospheric 14CO2. The diet ages were estimated to be 12–18, 7–13 and 5–9 years for the wood‐feeder (Microcerotermes crassus), the soil‐feeders (Dicuspiditermes makhamensis and Termes comis) and the fungus‐grower (Macrotermes carbonarius), respectively. One colony of soil‐feeder (T. comis), which nested in a fallen tree trunk, had exceptionally low 14C content, and its diet age was estimated to be around 50 years. The two bee species had lower 14C contents compared with the termites, and their diet ages were estimated to be 0 (Apis florea) and 2–4 years (Trigona sp.). Stable C and N isotope ratios of termites showed similar patterns as previously reported, and no clear difference was observed between 1998 and 2004. Although the bees and the fungus‐growing termite had similar stable C and N isotope ratios, their diet ages differed. Our study suggests that radiocarbon can be used to estimate the diet ages of consumers in terrestrial food webs. Diet age should provide new insight into the trophic positions of organisms in grazing and detrital food webs and the interactions between these two webs.

Termite ecology in a dry evergreen forest in Thailand in terms of stable (δ13C and δ15N) and radio (14C, 137Cs and 210Pb) isotopes

Stable (δ13C and δ15N) and radio‐ (14C, 137Cs and 210Pb) isotopes were determined for termites that have been sampled from a dry evergreen forest in Thailand. A wood‐feeding termite, Microcerotermes crassus, was separated from soil‐feeders: Termes propinquus, Termes comis and Dicuspiditermes makhamensis by δ13C and δ15N values. The Termes group in Thailand had less diverse values in δ13C and δ15N than those in Australia, where the feeding habits of the ‘Termes’ group are more diverse. Other soil‐feeding termites produced similar δ13C values, but a larger range in δ15N values. 14C‐percent modern carbon (pMC) values suggest that the soil‐feeding termites used younger carbon than the wood‐feeding termites, and this was consistent with the termites from Cameroon, central Africa. Values of δ13C and 14C‐pMC indicate that surface soil was used by a soil‐feeding termite, D. makhamensis, in making the nest mounds, and deeper soil (10–30 cm) by a fungus‐growing termite, Macrotermes carbonarius. 210Pb and 137Cs were scarcely incorporated into the termites, although 214Pb was recovered from the workers. The results suggest that stable‐ and radioisotopes are useful in the study of detritivorous animals, organic matter decomposition and ecosystem engineering.

Underground passage system of Macrotermes carbonarius (Isoptera, Termitidae) in a dry evergreen forest of northeast Thailand

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.

Trunk Trail Foraging of the Fungus-Growing Termite Macrotermes carbonarius (Hagen) in Southeastern Thailand.

The temporal and spatial change of foraging activity of Macrotermes carbonarius (Hagen) was studied in a durian orchard of southeastern Thailand. This termite is the only open-air foraging species of the fungus-growing Macrotermitinae. Workers constructs “pavement” trackways on the ground, which are used as trunk trails to connect foraging holes to foraging sites. This is the first paper to show the trunk trail foraging in fungus-growing termites. The major workers made pavement trackways paved with soil and fecal pellets which open-air foraging columns used for traveling to the foraging area. The pavement trackway was longer than the subterranean gallery. Foraging workers spread from the end of the pavement trackway onto the foraging area, where they picked up dead grass from the ground surface and carried it into the foraging hole. The soldiers led the advancing column to a foraging site and guarded both sides of the column, facing away from the column’s edge. The outskirts of foraging area were guarded by minor and major soldiers and several minor soldiers always went ahead of the column, playing the role of scouts. Foraging took place only in the dry season and at night, and foraging areas were changed irregularly. In most instances, a single foraging site and one foraging hole was used for each foraging bout. The same pavement trackways and foraging sites were rarely used for two consecutive days.

The physical and chemical composition of mounds of Macrotermes carbonarius (Hagen) (Termitidae, Macrotermitinae), in Penang, Malaysia

SUMMARYThe mound of the fungus‐growing termite Macrotermes carbonarius (Hagen) contained significantly larger proportions of clay (P&lt;0.05) than the adjacent soil. The largest clay content was found in the brood chamber. Concentrations of organic carbon, nitrogen, potassium and calcium in various parts of the mound were enriched compared to the adjacent soil at 10–40 cm depth from which they might have been derived. The activities of M. carbonarius did not significantly alter the pH or the bulk density of the mound soil compared to the adjacent topsoil.