Rhinotermitidae Research Articles

Mitochondrial DNA sequence-based identification of two subterranean termite species, from Riyadh Province, Kingdom of Saudi Arabia.

Termites are economically important wood-destroying and agricultural pests. The termite fauna almost consists of 2900 described species in 286 genera worldwide. In the present study, hundreds of termite samples from 42 different locations in the Riyadh province were collected. These samples were previously used for morphometric identification and reported two subterranean termite species, Coptotermes heimi and Psammotermes hypostoma, in the family Rhinotermitidae. In the present study, these samples were analysed using DNA barcoding with the mitochondrial cytochrome c oxidase subunit 1 gene to confirm the conventional taxonomical identification on a molecular basis. The obtained COI gene sequences of all 42 termite specimens were submitted to GenBank (accession numbers: ON529959-ON529969, OP825131-OP825132, and OP890882-OP890910). Eleven of the 42 samples were thus identified as C. heimi and the remaining 31 samples as P. hypostoma, which were phylogenetically analysed. All the 11 C. heimi sequences were grouped in a single clade, indicating close relatedness. While 31 sequences of P. hypostoma constituted two clades in the phylogenetic tree. Pairwise nucleotide sequence identity and divergence analysis showed that C. heimi sequences showed high nucleotide identities of 87.6-99.5% and less divergence ranging from 0.5% to 13.6%. Similarly, sequences of P. hypostoma also showed high nucleotide identity of 78.6-100% and low divergence among them ranging from 0-10.7%. A further application, significance, and shortcomings of COI-based DNA barcoding have been discussed. DNA barcoding using the COI gene is a reliable tool to distinguish C. heimi and P. hypostoma genotypes.

Nitrogen fixation in different termite lineages and diets

Abstract Nitrogen fixation is often cited as an important nitrogen source for termites. However, the rate of nitrogen fixation between experiments and termite species is highly variable due to termite diversity and sampling limitations. New evidence suggests that subterranean termites (Coptotermes formosanus Shiraki) (Blattodea, Rhinotermitidae) seek alternative dietary nitrogen sources for colony growth and development. This study compares N2 fixation rates and nitrogenase gene expression rates to a diverse assemblage of feeding groups. It was observed that nitrogenase expression was much higher in one-piece nesting termites from the family Kalotermitidae which lack access to soil. On the other hand, subterranean termites from the family Rhinotermitidae fix nitrogen at much lower rates, not differing from ambient nitrogenase activity in soil.

Effects of soil moisture on tunneling, survivorship, and food consumption of the Formosan and eastern subterranean termites (Blattodea: Rhinotermitidae).

Soil moisture is a critical environmental factor for the survival and behavior of subterranean termites (family Rhinotermitidae). The invasive Formosan subterranean termite, Coptotermes formosanus Shiraki, and the native eastern subterranean termite, Reticulitermes flavipes (Kollar), co-occur in the southeastern United States, while R. flavipes is distributed in a wider geoclimatic range. Previous studies showed that subterranean termites preferred higher soil moisture levels for tunneling and feeding; however, the impacts of constant moisture remained to be characterized to understand their moisture tolerance. In this study, we hypothesized that different soil moisture regimes can alter termite foraging and survival, and that the effects differ between the two species. The tunneling activity, survivorship, and food consumption of termites were documented for 28 days with different sand moisture conditions ranging from no moisture to full saturation (0%, 1%, 5%, 15%, 25%, and 30%). We found that there were no significant differences in the responses between C. formosanus and R. flavipes. In both species, termites did not survive or tunnel with 0% moisture. Termites performed tunneling with only 1% sand moisture, although they did not survive for 28 days. A minimal of 5% sand moisture was required for survival, and there were no significant differences in survivorship, tunneling activity, or food consumption among moisture contents of 5-30%. The results suggest that subterranean termites are resilient to moisture extremes. Colonies can tolerate low moisture conditions in their foraging environment for extended times, which may allow them to tunnel and find new moisture sources for colony survival.

Largest on earth: Discovery of a new type of fairy circle in Angola supports a termite origin

1. Circular bare patches occur in high numbers among the vegetation of the Namib Desert margin. There is an ongoing scientific debate on the origin of these so‐called “fairy circles” (FCs). One of the most frequently discussed hypotheses regards the bare patches to be the result of localised herbivory by sand termites of the genus Psammotermes (family Rhinotermitidae).2. In all earlier publications, the fairy circles of the Namib Desert region within their entire range from Angola through Namibia to South Africa were, in principle, regarded to be of one type, albeit increasing in size towards the north. Here we present evidence that at −16.23° latitude there is an abrupt discontinuity which separates the FCs on either side from each other.3. South of this discontinuity all studied FCs share the properties of the previously described fairy circles in Namibia and South Africa, especially the presence of Psammotermes termites.4. In contrast, north of −16.23°S the FCs are much larger and are caused by a different and undescribed termite species, most closely related to the harvester termite genus Microhodotermes (family Hodotermitidae). The two sets of fairy circles differ in a specific set of morphological features, associated termites, and soil parameters.5. The observed juxtaposition of the newly discovered large structures caused by a hodotermitid termite and the Psammotermes FCs caused by a rhinotermitid species is interpreted as an interesting example of convergent evolution resulting in similar ecological structures.

Carbon ecology of termite gut and phenol degradation by a bacterium isolated from the gut of termite.

Metagenomics and transcriptomics have had some success analyzing community and functional ecology of the termite gut, but carbon utilization ecology and the effect of diet on the gut community are not well understood. This study was done to determine the effect of three hardwood tree types, oak (Quercus spp.), red maple (Acer rubrum), and tupelo (Nyssa aquatica) on the termite species, Reticulitermes flavipes in the family Rhinotermitidae. Termite abdomen homogenates were incubated on agar plates containing three common carbon sources in the termite gut, namely, acetate, cellobiose, and phenol under aerobic and anaerobic conditions. Bacterial growth was higher on cellobiose than any other carbon source. Higher bacterial growth on cellobiose was observed from termite colonies feeding on oak than on phenol from the other two wood types. The difference between aerobic and anaerobic conditions was not significant. A bacterium, Acinetobacter tandoii isolated and identified from our previous study was subjected to high concentrations of phenol as the sole carbon source and this bacterium was able to degrade phenol concentration up to 600mg/L.

Evaluation of the virulence of entomopathogenic fungus, Isaria fumosorosea isolates against subterranean termites Coptotermes spp. (Isoptera: Rhinotermitidae)

The entomopathogenic fungus Isaria fumosorosea Wize, formerly known as Paecilomyces fumosoroseus is reported as a promising biocontrol agent for controlling subterranean termites, particularly those belonging to the family Rhinotermitidae. In Malaysia, the family Rhinotermitidae includes two species of subterranean termites with extremely high economic importance; namely Coptotermes curvignathus Holmgren, and the Asian Subterranean Termite (Coptotermes gestroi Wasmann). To comprehend the potential control of this soil-dwelling fungus against these subterranean termites in Malaysia, an investigation was carried out by testing the pathogenecity of 11 isolates against these termite species. All isolates showed pathogenic potential against the termite (Mortality rate of C. curvignathus: 84.4%; C. gestroi: 67.3%). Isolate PF49 was the most effective against both species of termites and was further tested for its virulence and mycosis. The LC50 values of PF49 against C. curvignathus and C. gestroi were 7.55 × 103 and 1.09 × 102 conidia/ml, respectively. The average number of days required to complete the mycosis process in C. curvignathus and C. gestroi were 4.7 and 8 days, respectively. These fungi are believed useful for protecting living trees, plants, wood, wood structures, and other cellulosic materials susceptible to termite infestation and damage.

Termites of Agropark, Universiti Malaysia Kelantan, Jeli Campus: Diversity and Pest Composition

Termites play important roles in the ecosystem as detritivores and soil engineers. However,alterations of the forest could change the diversity and abundance of termites. The Agropark atUniversiti Malaysia Kelantan (UMK), Jeli Campus is an agricultural park that is surrounded bysecondary forest and rubber plantations. This study was conducted to determine the diversity andpest species composition of termites at Agropark, UMK. Standardized line transects 100m long ×2m wide and divided into 20 sections (5m long × 2m wide) were conducted at three differentsampling sites in May to September 2015. A total of 29 termite species from 13 genera weresuccessfully identified with relative abundance of 128 (total hits). Diversity indices show highdiversity and evenness among the termite species in the study area. The termites comprise offamily Termitidae (75.9%) and family Rhinotermitidae (24.1%). Subfamily Macrotermitinaerecorded higher a number of species (12 species, 78 hits) compared to other subfamilies recordedin this study. Wood feeders and epigeal mound builders dominated the termite assemblages. Thetotal pest termite species collected is 41.4% (12 species) while 58.6% (17 species) of termitespecies were non-pest species that provide good ecological services to Agropark, UMKKJ. Thepests are mainly from genera Coptotermes, Schedorhinotermes, Macrotermes, Microtermes andGlobitermes. The higher number of pest species shows the possibility of pest attacks to thebuildings around the Agropark. Precautions against termite attack should be taken earlier toprevent serious damage to buildings in the future.

Termites (Insecta: Blattodea) buildings in urban located in the municipality of Seropédica, RJ

The Termites (Blattodea) are insects found between latitudes 52° N e 45° S in temperate climate places, such as in tropical areas. In Brazil, about 300 species were recorded belonging to four families: Kalotermitidae, Rhinotermitidae, Serritermitidae and Termitidae. Considered eusocial, they form colonies of individuals with overlapping generations, cooperative care of offspring and labor division. They develop by paurometabolism and are classified in caste with specific tasks within the colony. The staple food of termites is cellulose, but its source varies according to the species. In natural vegetation areas, termites have got an important ecological role, participating actively in recycling and decomposition of nutrients in ecosystems they inhabit. Besides of the positive contribution in changing soil porosity and aeration. In urban areas, 10% of the species are taken as plagues, causing enormous losses, explicit in cost with prevention, control and repair. Damage caused by termites in urban areas are mainly attributed to the species: Cryptotermes brevis (Walker, 1853), Coptotermes gestroi (Wasmann, 1896) and Nasutitermes corniger (Motschulsky, 1896). Therefore, identifying termites species that colonize urban households in the municipality of Seropedica, RJ, has been the objective of this study. Three urban neighbourhoods: Fazenda Caxias, Boa Esperanca and Ecologia, were sampled. Building were inspectied and owners interviewed, totalling twelve residents per block in fifteen blocks per neighbourhood. Proportion of infested buildings with each species was made suing the χ 2 test and the probability level, from which a comparison was considered significant, was equal to the risk probability at 5% divided by the number of comparisons. Of the total 540 inspections, 30% of the households had occurrence of termites of which 50% C. brevis, 42% C. gestroi and 8% N. corniger. Coexistence of species within a residence was found in only 3% of the inspected households. The occurrence of moisture spots in residences was found in 34% of the most infested households (44%) over the moisture spotless (22%). Infestation history in the past five years was recorded in 31% of the households and in general, residences with previous history, were more infested (58%) than the residences without history (17%). Generally, the infestation by termites takes place via exotic and native species, being the exotic species more relevant in colonization of the municipality residences. Occurrence of N. corniger has not been identified at Ecologia neighbourhood, which had greatest occurrence of C. gestroi in attacked residences. Buildings without moisture spots are predominantly infested by C. brevis. The species C. gestroi and C. brevis are the most seen in residences with infestation history, whilst residences without infestation are predominantly damaged by the species C. brevis.

The parabasalid symbiont community of Heterotermes aureus: Molecular and morphological characterization of four new species and reestablishment of the genus Cononympha

The subterranean termite Heterotermes aureus is endemic to arid regions of southwestern USA and northern Mexico. Like other termites in the family Rhinotermitidae, it harbors a community of protists (Phylum Parabasalia) in its hindgut that aid in cellulose digestion. We investigated the hindgut community of H. aureus using light microscopy, single cell isolation, and high throughput amplicon sequencing. Here we describe four new parabasalid species from the classes Trichonymphea and Spirotrichonymphea. Three of the new species include Pseudotrichonympha aurea (Trichonymphea), Holomastigotoides aureus, and Holomastigotoides oxyrhynchus (Spirotrichonymphea). The fourth new species is a Spirotrichonympha-like protist for which we reinstate the genus Cononympha and describe under the name Cononympha aurea (Spirotrichonymphea). We also used high throughput amplicon sequencing with custom primers on DNA from fresh and ethanol preserved termites collected across the southwest USA and Mexico to investigate population-level differences in hindgut community composition. We report that the community is highly similar across populations: no additional parabasalid species were identified in any of the H. aureus specimens, but several specimens appeared to lack either C. aurea or H. oxyrhynchus.

The Impact of Tropical Peat Fire on Termite Assemblage in Sumatra, Indonesia: Reduced Complexity of Community Structure and Survival Strategies.

Tropical peat swamp forests in Southeast Asia account for approximately 72% of global peatland. However, extensive forest exploitation following peat drainage for agricultural expansion has been leading to catastrophic peat fires. In this study, we compared the termite assemblage in burnt and unburnt peats in Sumatra, Indonesia. We also identified which taxonomic group is particularly resistant to fire disturbance and the traits that correlate with its persistence in fire-impacted peatlands. Overall, the termite species richness in fire-impacted peats was up to 40% lower than that of the total species found in peat swamp forests. Although the estimated species richness values in fire-impacted peats and peat swamp forests were not significantly different, fire changed termite community structure significantly. Only termites of the family Rhinotermitidae survived in the fire event, whereas members of the Termitidae that were reportedly resilient to fire and open habitats elsewhere disappeared during the fire events. The rhinotermitids found in the burnt sites were exclusively wood nesters. This suggests that the desiccation tolerance of termites in open habitat is not the simple underlying survival strategy, but tree branches and barks might have provided a refuge from heat during fire. The result also suggests that the high similarity in species composition in recently burnt peats and long burnt peats implies low species turnover. Thus, regardless of how much time had passed since the fire-impacted peats were abandoned or cultivated, the increase in habitat complexity did not favor colonization by the forest-dependent group.

Termite (Isoptera) genera in crop environments

A preliminary survey was conducted by transect method throughout the instructional farm area of the College of Horticulture, Vellanikkara and the soldier castes of termites were sampled from a unit area of 200 sq. m each from various crop environments. The collected samples were preserved and identified based on taxonomic keys with reference to their characteristics of head capsule, mandibles and pronotum. A total of nine genera under two families were identified; out of which seven genera viz., Odontotermes, Procapritermes, Dicuspiditermes, Homallotermes, Microtermes, Microcerotermes and Nasutitermes were under the family Termitidae and Heterotermes and Coptotermes were of the family Rhinotermitidae. Odontotermes was found to be the most dominant in all the crop environments accounting for about 62.03%. The least occuring was Coptotermes which constituted only 1.27%.

Genetic Relationship Among Indian Termites Based on DNA Sequence of Mitochondrial 12S Ribosomal RNA Gene

Partial 12S gene fragments were amplified by using specific primers in nine species of termites of the genus Odontotermes, Microtermes and Microcerotermes (Isoptera: Termitidae: Macrotermitinae), and the PCR products were subjected to sequence analysis. The sequences obtained were characterized to see the frequencies of each nucleotide bases, and high A+T content was observed. The divergence of the species was found be lower within the same family, and highest with species from the family Rhinotermitidae. Phylogenetic tree drawn on the basis of distance Neighbour-joining method revealed clustering of individuals according to their genera and families.

Efficacy of Altriset® on the Tropical Arboreal Termite,Nasutitermes corniger(Isoptera: Termitidae: Nasutitermitinae)

Nasutitermes corniger (Motschulsky), a memSpray Applications ber of the termite family Termitidae, is an im portant structural pest over much of Central and A 4.6-cm-diam, 1-mm-thick cellulose pad (Gel South America (Constantino 2002; Torales 2002) man inc.) was placed inside a 5.5 cm plastic Pe and the West Indies including Puerto Rico and the tri dish bottom and moistened with 1.25 mL of U.S. Virgin Islands (Scheffrahn et al. 2003). This water. Twenty-five workers of N. corniger, as ob termite has now invaded South Florida (Scheftained above, were placed on top of the pad. The frahn et al. 2002), the Bahamas (Scheffrahn et al. termites were taken from a whole field-collected 2006), and New Guinea (Scheffrahn et al. 2005). colony that was maintained in the laboratory in DuPontTM Altriset® is a newly registered termitia 40 gallon (148 L) aquarium tank. Eight repli cide containing the active ingredient, chlorantracates were sprayed with 500 ppm aqueous Altri niliprole, which is characterized by its extremely set® and eight control replicates were sprayed low mammalian toxicity (Lahm et al. 2007) and with water. The liquid spray concentration of its high efficacy against subterranean termites 500 ppm (0.05%) is the current label application (family Rhinotermitidae e.g., Mao et al. 2011; rate for the commercial product. The sprays were Neoh et al. 2012; Spomer & Ramble 2011). The deposited from a distance of 35 cm using a hand efficacy of Altriset® against higher termites (Tersprayer set to deliver medium/fine droplets. For mitidae) has not been evaluated. Given the toxiceach treatment (Altriset® or water) 4 pumps ity of Altriset® against conordinals, the purpose mL total) were applied. About 2 mL actually of this study was to assess the efficacy of residual landed inside all the replicates of each treatment, and spray treatments of Altriset® on N. corniger Within five minutes, the sprayed termites were workers using laboratory bioassays. transferred to identical clean, unsprayed, Petri dishes containing damp pads. Lids were placed on o „ the pads and the 16 dishes were placed in a labo oi xposures ratory incubator at 22 °C and 90% RH. Termite Altriset® (18.4% chlorantraniliprole AI, Dumortality and moribundity were recorded once or Pont Professional Products), was applied to sand twice Per day> a& time allowed, for 7 days, (natural play sand, Sakrete, Bonsai America, Table 1 and Fig. 1 summarize time versus Charlotte, North Carolina) in aqueous solutions mortality for the five treatments prepared for and thoroughly mixed by hand for final dry conthis study. In all Altriset® exposures, locomotion centrations (wt Al/wt sand) of 100 ppm, 50 ppm, of Ncorniger workers slowed markedly, followed and 0 ppm water only). The 50 ppm concentraby moribundity. Moribundity preceded mortal tion is approximately the conventional soil apity by about 0.5-2 days. The 500 ppm Altriset® plication rate. For each treatment, 9 g of the spray treatment yielded 44% mortality by 65 dry treated sand was poured into an 8.2 cm ID hours and reached 100% mortality in 161 hours plastic Petri dish bottom to which 6 mL of wapost-exposure compared to 4% mortality for the ter was added. Twenty five (25) workers of N. water-only spray treatment. The 100 ppm Altri corniger were then placed on top of the damp set® sand treatment produced 100% mortality sand and a matching lid was used to close each by 25 h while the 50 ppm treatment yielded 1% bioassay unit. Each treatment was replicated 8 mortality over this time period. However by 73 h, times. Termites were taken from a single large the 50 ppm sand exposure produced 45% mortal colony collected in Dania Beach, FL, in Dec 2011 ity and by 161 h, mortality rose to 99%. At 161 h, and maintained in the laboratory under ambithe mortality in the water-only sand treatment ent conditions in a 148-liter aquarium. Termites was 'ess than 4%. were fed dead Schinus wood and damp cellulose This laboratory study attempts to represent sponges. The 24 units were placed in a laboratotypical routes of field exposure to N. corniger. ry incubator at 22 ± 0.5 °C and 90% RH. Termite During a commercial application of liquid termiti mortality and moribundity were recorded once cide (surface spray and injection), most termites or twice per day for 7 days. will be exposed to the liquid termiticide through

Comparative Lignocellulase Activity and Distribution Among Selected Termite (Isoptera) Genera

Lignocellulase activity and distribution within the alimentary canal were compared among 4 termite (Isoptera) genera representing 2 taxonomic families: Coptotermes and Reticulitermes in Rhinotermitidae; Macrotermes and Odontotermes in Termitidae. Activity of (β-glucosidase and xylanase was higher in Macrotermes barneyi Light than observed in 5 other termite species examined; thus, indicating that M. barney might be a prospective organism for discovery of novel lignocellulases. Xylanase activity was primarily restricted to the hindgut of Coptotermes formosanus Shiraki, Reticulitermes guangzhouensis Ping, and R. dichrous Ping (Family Rhinotermitidae); whereas, xylanase activity occurred in both the midgut and hindgut of M. barneyi, Odontotermes formosanus (Shiraki), and O. hainanensis (Light) (Family Termitidae). β-glucosidase activity was primarily detected in the salivary gland and foregut of O. formosanus and O. hainensis, but β-glucosidase activity was equally distributed in salivary glands, foregut, and midgut of M. barneyi.

Revision of the termite family Rhinotermitidae (Isoptera) in New Guinea.

Recently, we completed a revision of the Termitidae from New Guinea and neighboring islands, recording a total of 45 species. Here, we revise a second family, the Rhinotermitidae, to progress towards a full picture of the termite diversity in New Guinea. Altogether, 6 genera and 15 species are recorded, among which two species, Coptotermes gambrinus and Parrhinotermes barbatus, are new to science. The genus Heterotermes is reported from New Guinea for the first time, with two species restricted to the southern part of the island. We also provide the first New Guinea records for six species of the genera Coptotermes and Schedorhinotermes. We briefly describe soldiers and imagoes of each species and provide a key based on soldier characters. Finally, we discuss the taxonomic and biogeographical implication of our results. A replacement name, Schedolimulus minutides Bourguignon, is proposed for the termitophilous staphylinid Schedolimulus minutus Bourguignon, to solve a question of secondary homonymy.

Asexual queen succession in the subterranean termite Reticulitermes virginicus

Termite colonies are founded by a pair of primary reproductives. In many species, including subterranean termites (family Rhinotermitidae), the primary king and queen can be succeeded by neotenic reproductives that are produced from workers or nymphs within the colony. It is generally believed that these neotenics inbreed within the colony, sometimes for many generations. Here, we show that primary queens of the North American subterranean termite, Reticulitermes virginicus, are replaced by numerous parthenogenetically produced female neotenics. We collected functional female neotenics from five colonies of R. virginicus in North Carolina and Texas, USA. Genetic analysis at eight microsatellite loci showed that 91-100% of the neotenics present within a colony were homozygous at all loci, indicating that they were produced through automictic parthenogenesis with terminal fusion. In contrast, workers, soldiers and alates were almost exclusively sexually produced by mating between the female neotenics and a single king. This is the second termite species shown to undergo asexual queen succession, a system first described in the Japanese species, Reticulitermes speratus. Thus, the conditional use of sexual and asexual reproduction to produce members of different castes may be widespread within Reticulitermes and possibly other subterranean termites.

Developmental pathways of Glossotermes oculatus (Isoptera, Serritermitidae): at the cross‐roads of worker caste evolution in termites

The onset of a specialized ("true") worker caste is a crucial step in the evolution of termite societies. Such workers, permanently excluded from wing development, repeatedly evolved from totipotent immatures, called "false" workers or pseudergates. In the family Rhinotermitidae, the presence of true workers and the level of specialization of this caste are highly variable, and key taxa illustrate transitional situations providing clues about worker evolution. Here we focused on the status of working immatures of Glossotermes oculatus, from the family Serritermitidae, now thought to represent either the sister-group of the Rhinotermitidae or a basal lineage nested within them. Contrary to previous assumptions, we show that the apterous immatures performing worker tasks in G. oculatus are the source of the single wing-budded nymphal instar preceding the alate. Consequently, they qualify as pseudergates rather than true workers. However, the sex ratio is strongly male biased in pseudergates and soldiers, which is a trait usually restricted to termites with true workers. We therefore argue that pseudergates of G. oculatus are close to a point where the species could easily shift toward the differentiation of a true worker caste, and that G. oculatus pinpoints a new possible route for the evolution of true workers from pseudergates.

Evolutionary trend of phylogenetic diversity of nitrogen fixation genes in the gut community of wood‐feeding termites

Nitrogen fixation by gut microorganisms is one of the crucial aspects of symbiosis in wood-feeding termites since these termites thrive on a nitrogen-poor diet. In order to understand the evolution of this symbiosis, we analysed the nitrogenase structural gene nifH in the gut microbial communities. In conjunction with the published sequences, we compared approximately 320 putatively functional NifH protein sequences obtained from a total of 19 termite samples that represent all the major branches of their currently proposed phylogeny, and from one species of the cockroach Cryptocercus that shares a common ancestor with termites. Using multivariate techniques for clustering and ordination, a phylogeny of NifH protein sequences was created and plotted variously with host termite families, genera, and species. Close concordance was observed between NifH communities and the host termites at genus level, but family level relationships were not always congruent with accepted termite clade structure. Host groups examined included basal families (Mastotermitidae, Termopsidae, Kalotermitidae, as well as Cryptocercus), the most derived lower termite family Rhinotermitidae, and subfamilies representing the advanced and highly diverse apical family Termitidae (Macrotermitinae, Termitinae, and Nasutitermitinae). This selection encompassed the major nesting and feeding styles recognized in termites, and it was evident that NifH phylogenetic divergence, as well as the occurrence of alternative nitrogenase-type NifH, was to some extent dependent on host lifestyle as well as phylogenetic position.

Cospeciation in the triplex symbiosis of termite gut protists (Pseudotrichonympha spp.), their hosts, and their bacterial endosymbionts

A number of cophylogenetic relationships between two organisms namely a host and a symbiont or parasite have been studied to date; however, organismal interactions in nature usually involve multiple members. Here, we investigated the cospeciation of a triplex symbiotic system comprising a hierarchy of three organisms -- termites of the family Rhinotermitidae, cellulolytic protists of the genus Pseudotrichonympha in the guts of these termites, and intracellular bacterial symbionts of the protists. The molecular phylogeny was inferred based on two mitochondrial genes for the termites and nuclear small-subunit rRNA genes for the protists and their endosymbionts, and these were compared. Although intestinal microorganisms are generally considered to have looser associations with the host than intracellular symbionts, the Pseudotrichonympha protists showed almost complete codivergence with the host termites, probably due to strict transmissions by proctodeal trophallaxis or coprophagy based on the social behaviour of the termites. Except for one case, the endosymbiotic bacteria of the protists formed a monophyletic lineage in the order Bacteroidales, and the branching pattern was almost identical to those of the protists and the termites. However, some non-codivergent evolutionary events were evident. The members of this triplex symbiotic system appear to have cospeciated during their evolution with minor exceptions; the evolutionary relationships were probably established by termite sociality and the complex microbial community in the gut.

Phylogeny of Australian Coptotermes (Isoptera: Rhinotermitidae) species inferred from mitochondrial COII sequences.

Six Australian species of Coptotermes are traditionally recognized, but recent cuticular hydrocarbon studies suggest that some of these may represent more than one species. An understanding of the phylogenetic diversity of Australian Coptotermes, particularly the pest species, is likely to be important for the improvement of termite management strategies. A study of phylogenetic relationships among species of this genus was performed, based on the mitochondrial cytochrome oxidase (COII) gene, comparing the data with recent data from Asian species. Representatives of the species C. lacteus (Froggatt), C. frenchi Hill and C. michaelseni Silvestri were each found to form closely related monophyletic groups, however representatives of C. acinaciformis (Froggatt) were not. For C. acinaciformis, representatives from northern mound-building populations were found to form a distinct group to southern, tree-nesting forms. Among southern C. acinaciformis, two Western Australian representatives were found to be divergent from other populations. The results suggest that C. acinaciformis probably represents a complex of species rather than one, as has been suggested previously. One unidentified Coptotermes sp. taxon from Melbourne was found to be divergent from other taxa. Notably, some Australian species were more closely related to Asian species than other Australian species.