A taxonomic index, with names of descriptive authorities of termite genera and species: an accompaniment to Biology of Termites: A Modern Synthesis (Bignell DE, Roisin Y, Lo N, Editors. 2011. Springer, Dordrecht. 576 pp.).

Biology of Termites: A Modern Synthesis (Bignell DE, Roisin Y, Lo N, (Editors), Springer, Dordrecht, 576pp, ISBN 978-90-481-3976-7, e-ISBN 978-90-481-3977-4, DOI 10.1007/978-90-481-3977-4) was published in 2011. With the agreement of the publishers, we give a taxonomic index of the book comprising 494 termite entries, 103 entries of other multicellular animal species mentioned as associates or predators of termites, with 9 fungal, 60 protist, and 64 prokaryote identities, which are listed as termite symbionts (sensu stricto). In addition, we add descriptive authorities for living (and some fossil) termite genera and species. Higher taxonomic groupings for termites are indicated by 25 code numbers. Microorganisms (prokaryotes, protists, and fungi) are listed separately, using broad modern taxonomic affiliations from the contemporary literature of bacteriology, protozoology, and mycology.

Survey of subterranean termites (Isoptera: Rhinotermitidae) in a managed silvicultural plantation in Portugal, using a line-intersection method (LIS).

Subterranean termites (Reticulitermes grassei) were surveyed over successive seasons in a managed eucalyptus plantation in southeastern Portugal for 26 months. Termite activity in seven diameter categories of lying dead wood was investigated by a modified line intersection method (LIS). Each item sampled was inspected and assessed for termite attack and for general (i.e. fungal) decay status using standard protocols. Line intersection is quantitative to the extent that it can link foraging and decay parameters to woody biovolume. It was found that termites selected items with larger diameter, the observed trend showing an exponential character with greater termite attack as diameter increased. Attack by termites was positively associated with prior decay by fungi. A clear positive relationship was shown between rainfall and total woody biovolume containing live termites, underlining the importance of moisture for termite activity. Subterranean termites appeared to be important wood decomposers in the woodland studied, with an average of 30% of lying dead wood branches showing signs of termite attack.

Distribution and genetic variation of Reticulitermes (Isoptera: Rhinotermitidae) in Portugal.

The genus Reticulitermes has a Holartic distribution and is widely represented in southern Europe. It is established in Portugal, across the full range of ambient environmental conditions, using different types of wood resources, as available, and nesting ubiquitously in many types of soil. Sequencing of part of the mtDNA COII gene revealed that all the specimens sampled on a north-south transect of the country were Reticulitermes grassei (considered synonymous with R. lucifugus grassei). Nevertheless, an association between the genetic and the geographical distances of sampled specimens was shown, leading to the conclusion that discrete termite populations have differentiated in situ. The geographic component of the genetic polymorphism should be the subject for further research.

Termite assemblages, forest disturbance and greenhouse gas fluxes in Sabah, East Malaysia.

A synthesis is presented of sampling work conducted under a UK government-funded Darwin Initiative grant undertaken predominantly within the Danum Valley Conservation Area (DVCA), Sabah, East Malaysia. The project concerned the assemblage structure, gas physiology and landscape gas fluxes of termites in pristine and two ages of secondary, dipterocarp forest. The DVCA termite fauna is typical of the Sunda region, dominated by Termes-group soil-feeders and Nasutitermitinae. Selective logging appears to have relatively little effect on termite assemblages, although soil-feeding termites may be moderately affected by this level of disturbance. Species composition changes, but to a small extent when considered against the background level of compositional differences within the Sunda region. Physiologically the assemblage is very like others that have been studied, although there are some species that do not fit on the expected body size-metabolic rate curve. As elsewhere, soil-feeders and soil-wood interface-feeders tend to produce more methane. As with the termite assemblage characteristics, gross gas and energy fluxes do not differ significantly between logged and unlogged sites. Although gross methane fluxes are high, all the soils at DVCA were methane sinks, suggesting that methane oxidation by methanotrophic bacteria was a more important process than methane production by gut archaea. This implies that methane production by termites in South-East Asia is not contributing significantly to the observed increase in levels of methane production worldwide. Biomass density, species richness, clade complement and energy flow were much lower at DVCA than at a directly comparable site in southern Cameroon. This is probably due to the different biogeographical histories of the areas.

Application of 13C NMR to investigate the transformations and biodegradation of organic materials by wood- and soil-feeding termites, and a coprophagous litter-dwelling dipteran larva.

Solid-state 13C nuclear magnetic resonance spectroscopy has been used to characterize the C in samples of the food (wood), gut contents and faeces from the wood-feeding termite, Microcerotermes parvus; soil in the guts and mound material from the soil-feeding termite, Thoracotermes macrothorax; and the food and faeces from the litter-feeding, coprophagous larvae of the dipteran fly, Bibio marci. Spectra from the wood-feeding termite indicated preferential loss of polysaccharide and accumulation of lignin with some modification to the O-aromatic-C and methoxyl-C (O-methyl-C) components during passage through the gut. Spectra for the soil-feeding termite indicated little change in the distribution of 13C between resonances following passage through the gut, except for some evidence of preferential polysaccharide loss. Interpretation of the spectra from these organisms was restricted by the relatively low C content of the soils and mound material, and by the large contribution to the NMR spectra from the gut tissue rather than the gut contents. Spectra for the litter-feeding dipteran larvae indicated preferential feeding on the polysaccharide-rich component of the litter and then overall loss of polysaccharide-C and accumulation of both aromatic-C and methoxyl-C in the gut. These changes were greater for the second passage than for the first passage through the gut, suggesting that principally mechanical and physical changes occurred initially and that chemical digestion was prevalent during the second passage.

On the respiratory quotient (RQ) of termites (Insecta: Isoptera).

The respiratory quotient (RQ) at 28 degrees C was determined by Warburg manometry in 23 species of termites from the Mbalmayo Forest Reserve (Cameroon) and three sub-tropical species cultured under laboratory conditions in the U.K. or freshly collected in Australia. The data are tabulated with other recently reported RQs (determined by manometry or GC) and with measured CH(4) emission rates to provide a survey of 29 species covering both lower and higher termites in all major trophic (functional) categories. In all species, except the wood-feeding Coptotermes acinaciformis and the soil-feeding Cubitermes fungifaber, the observed mean values (with manometry corrected for known fluxes of H(2) and CH(4)) were at or well above 1.00. Soil-feeding forms (except C. fungifaber) generally showed a high apparent RQ (not corrected for H(2)), with nine species (out of 13) above 1.20 and six species above 1.30. Well-replicated laboratory experiments with Reticulitermes lucifugus showed that there was a tendency for RQ to fall with time over a 4-h incubation, although remaining greater than 1.00.The observed RQs are consistent with carbohydrate being the principal substrate supporting respiration in all trophic and taxonomic categories, with little or no contribution from the degradation of lignin or other polyaromatic materials. However, in many species (especially soil-feeders), the observed RQ is greater than that expected from known fluxes of O(2), CO(2) and CH(4) on the assumption that carbohydrate is the respiratory substrate. This presupposes that there is a large hydrogen sink (additional to CH(4) production), possibly the emission of H(2) gas, and/or the existence of unresolved digestive mechanisms or electron routings. Uncertainties in the use of manometry with termites are discussed.

Functions of symbiotic fungus gardens in higher termites of the genus Macrotermes: evidence against the acquired enzyme hypothesis.

Behavioural, microbiological and biochemical studies on Macrotermes subhyalinus and M. michaelseni by collaborating laboratories in the U.K., Switzerland and Australia are described. Younger workers consume both primary forage and the conidia of a symbiotically associated fungus of the genus Termitomyces, but all workers produce a fully competent cellulase complex (endoglucanase + glucosidase) in the midgut which is clearly distinguishable from analogous enzymes in fungal tissues. Workers have a RQ of 1.0; although a bacterial flora is present, assessments of CH4/H2 efflux and intestinal VFAs suggest that respiration is sustained by aerobic carbohydrate dissimilation. Calculations based on estimates of food ingestion by workers and measurements of cellulase activity show that endogenous production of reducing sugars from polysaccharide is sufficient to sustain the observed metabolic rate. Conidia contain both cellulase and glucose at much higher concentrations than other fungal tissues, but the role and fate of these substances on entering the young worker guts is unknown. Older workers consume fully composted forage in which cellulose, hemicellulose, pectin and lignin are all significantly degraded, with a corresponding increase in nitrogen content.

Formation of membrane-bounded secretory granules in the midgut epithelium of a termite, Cubitermes severus, and a possible intercellular route of discharge.

Mature columnar cells of the midgut of Cubitermes contain a prominent secretion product observed at light- and electron-microscopic levels. At the ultrastructural level the product is resolved as an electron dense material contained in vesicles up to 1 micron diameter that accumulate in the apical cytoplasm. The vesicles are composite, apparently formed by coalescence of at least two types of precursor vesicle both of which originate from the Golgi apparatus. Discharge of the product takes place by exocytosis into intercellular space at or in the vicinity of the apical septate junction complex. Augmentation of apical surface area by microvilli is less prominent in Cubitermes than in other termites for which data are available. This and other evidence suggests that absorptive functions are reduced in the midgut of this insect.

Distribution and abundance of bacteria in the gut of a soil-feeding termite Procutiermes aburiensis (Termitidae, Termitinae).

The alimentary canal of a representative species of soil-feeding termite was examined for associations with bacteria. Enumerations made in the principal regions of the intestine by direct observation and expressed for comparative purposes as total microbial standing crop showed a net three- to fourfold increase between the foregut (crop) and rectum. Filamentous organisms, putatively actinomycetes, contributed significantly to the flora in most regions of the gut and were more abundant, relative to non-filamentous forms, than in freshly ingested soil. Transmission and scanning electron microscopy of the gut wall showed that the actinomycetes formed novel associations with the host in the mesenteron, mixed segment and colon. Non-filamentous organisms, chiefly rods, colonized the walls of the first proctodaeal segment and the colon, in addition to filaments, and were present in large numbers in the contents of the third proctodaeal segment.

An ultrastructural study and stereological analysis of the colon wall in the cockroach Periplaneta americana.

The colonic epithelium has been examined for ultrastructural evidence of physiological activity. The cells show extensive folding of the apical plasma membrane, associated with mitochondria and an internal coating of particles about 120 A diameter. Anteriorly many apical infoldings are dilated at the tip to form substantial extracellular spaces up to 0.8 micron wide. Narrow intercellular channels are present, opening to the haemolymph side of the epithelium. Pinocytosis is seen frequently at the basal surface. The surface densities of apical plasma membranes were not significantly different in the posterior mid-gut and colon. Similarly the volume densities of mitochondria were equal in the colonic epithelium and rectal pads, but the surface density of outer mitochondrial membranes was greater in the colon. It is suggested that the colon may absorb organic solutes from the gut lumen.

Association of actinomycete-like bacteria with soil-feeding termites (termitidae, termitinae).

Electron microscopy of the hindgut showed that actinomycete-like bacteria were the principal microbial associates of two African species of soil-feeding termites. Elongated cuticular spines provided attachment.