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Oceanic rafting through driftwood has been hypothesized to be a mechanism underlying the transoceanic distribution of termites (Order: Blattodea). To test this hypothesis, we examined the salinity tolerance of 12 termite species from eight genera and three families, namely Archotermopsidae, Kalotermitidae, and Rhinotermitidae. Our results revealed that the survival rates of Incisitermes inamurai (Oshima), Cryptotermes domesticus (Haviland), Prorhinotermes flavus (Bugnion and Popoff), P. simplex (Hagen), and Heterotermes sp. are not affected by treatment with 3.5% saline water, strongly supported that oceanic rafting may be a mechanism underlying the insects' transoceanic distribution. By contrast, Hodotermopsis sjostedti Holmgren, Glyptotermes satsumensis (Matsumura), Coptotermes formosanus Shiraki, Co. gestroi (Wasmann), Reticulitermes virginicus (Banks), R. leptomandibularis Hsia and Fan, and R. kanmonensis Takematsu treated with saline water showed dehydration symptoms, and their mortality rates increased significantly within 12 days after treatment. These results indicate that these species are less likely to be dispersed through oceanic driftwood and that their transoceanic dispersal is rather more likely to occur through human transportation or land bridges. Phylogenetic positions and habitats of salinity‐tolerant termites implied that the acquisition of salinity tolerance may relate to both phylogeny and coastal living.

Subterranean termite nests are located underground and termites forage out by constructing tunnels to reach food resources, and tunneling behavior is critical in order to maximize the foraging efficiency. Excavation, transportation, and deposition behavior are involved in the tunneling, and termites have to move back and forth to do this. Although there are three sequential behaviors, excavation has been the focus of most previous studies. In this study, we investigated the deposition behavior of the Formosan subterranean termite, Coptotermes formosanus Shiraki, in experimental arenas having different widths (2, 3, and 4 mm), and characterized the function of deposited particles. We also simulated moving distance of the termites in different functions. Our results showed that total amounts of deposited particles were significantly higher in broad (4 mm width) than narrow (2 mm) tunnels and most deposited particles were observed near the tip of the tunnel regardless of tunnel widths. In addition, we found that deposited particles followed a quadratic decrease function, and simulation results showed that moving distance of termites in this function was the shortest. The quadratic decrease function of deposited particles in both experiment and simulation suggested that short moving distance in the decrease quadratic function is a strategy to minimize moving distance during the deposition behavior., Subterranean termites nest underground and forage out by constructing a network of tunnel. Tunneling behavior of the termites is composed of excavation, transportation, and deposition, and little is known for deposition behavior. We found that deposited particle distribution in the tunnel followed a quadratic decrease function in the experiment. In addition to the experiment, the simulation results revealed the shortest moving distance was observed in the quadratic decrease function.

BACKGROUND The lethal time of a chitin synthesis inhibitor (CSI) baited colony of Coptotermes formosanus Shiraki largely depends on the time for workers to molt after consuming a lethal dose. Given that termite molting biology can regulate the time for elimination of a baited termite colony, the objective of this study was to determine how the fasting period (an important element of worker's molting cycle) and the acquisition of lethal dose can impact the total elimination period for a colony. RESULTS Within 9 wk, noviflumuron eliminated the foraging population in the 30 m long foraging arena. However, mortality in treatment groups did not begin until the 11th day. The 10 d lag post treatment is the fasting period for workers to prepare for ecdysis on the 11th d during which mortality occurs under the effect of CSI. CONCLUSION This study shows that with the exception of successful molting events during the first 10 d after baiting, mortality amongst workers with lethal doses of noviflumuron in the next molt is inevitable. The 10 d fasting period can make up at least 22% of a molt cycle (=45 d for a fourth worker instar or lower) which can be a window of opportunity for a worker to escape from the effect of CSI baits, thereby, extending the total time for the colony elimination.

BACKGROUND In experiments with Formosan Subterranean Termites (Coptotermes formosanus Shirakii), myo-inositol-2-monophosphate as the di-cyclohexylammonium salt was tested among other sugar derivatives, and was found to be toxic to C. formosanus when added to a moistened filter paper food source in plastic petri dishes. RESULTS Curiously, over a 9 day period, the moniliform (beaded) antennae of C. formosanus deteriorated in a stepwise fashion with the most distal pseudosegment (bead) turning brown and falling off, followed by the penultimate pseudosegment, sequentially until 7–9 days when only a stub of the antennae remained. Termites became increasingly moribund with the loss of antennae, and quit normal behavior including consuming cellulose food, and died. sn-L-glycerol-3-phosphate as the di-cyclohexylammonium salt also gave the same results. Dicyclohexylammonium hydrogenphosphate and monocyclohexylammonium dihydrogenphosphate were synthesized, to find a low cost form for application to baits, both of which also showed similar toxicity. In a trial with Fibonacci series dilutions of neat cyclohexylamine, the antennae-effecting activity became apparent in the LD30 (14 days) to LD70 range of concentrations. At the higher concentrations, darkening of the most distal parts of leg extremities were noticed. CONCLUSION Cyclohexylamine appears to be a novel termiticide with a previously unreported mechanism of toxicity. It's hydrogen phosphate salts retain the toxic effect and are inexpensive and easily synthesized.

Spirotrichonymphea is a class of hypermastigote parabasalids defined by their spiral rows of many flagella. They are obligate hindgut symbionts of lower termites. Despite more than 100 yr of morphological and ultrastructural study, the group remains poorly characterised by molecular data and the phylogenetic positions and taxonomic validity of most genera remain in question. The genus Spirotrichonympha has been reported to inhabit several termite genera, including Reticulitermes, Coptotermes, and Hodotermopsis. The type species for this genus, Spirotrichonympha flagellata, was described from Reticulitermes lucifugus but no molecular data are yet available for this species. In this study, three new Spirotrichonympha species are described from three species of Reticulitermes. Their molecular phylogenetic position indicates that the genus is not monophyletic, as Spirotrichonympha species from Coptotermes, Paraneotermes, and Hodotermopsis branch separately. In contrast, the genus Holomastigotoides is monophyletic, as demonstrated using new sequences from Holomastigotoides species. The presence of Holomastigotoides in Prorhinotermes and the distinct phylogenetic positions of Spirotrichonympha from Reticulitermes and Coptotermes are consistent with a previously proposed symbiont fauna replacement in the ancestor of Reticulitermes.

Aim The Australian Coptotermes (Family: Rhinotermitidae) are a small monophyletic group of termites, some of which build mounds. In this study, we construct predicted distributions based on environmental data (niche models) for all Australian species of Coptotermes to test whether specific environmental factors have contributed to the evolution of mound-building behaviour and whether the degree of niche similarity and degree of phylogenetic similarity are correlated. Location The Australian mainland, including the known native ranges of all Australian species of Coptotermes. Methods We estimated the phylogenetic relationships between the species of Australian Coptotermes. We then generated and compared environmental niche models in a phylogenetic framework for all study species to test niche conservation. Our analyses were based on location data from our own sampling and from the Atlas of Living Australia, genetic data from a previous study of Australian Coptotermes, and environmental data from WorldClim and ASRIS. Results We found that no environmental variable differed consistently between mound-building and non-mound-building taxa and that the differences in niches between pairs of Australian species of Coptotermes are uncorrelated with time since divergence. The environmental tolerances of the Australian Coptotermes termites are more restricted by rainfall than they are by soil or temperature. Main conclusions Our results show that mound-building behaviour has not necessarily evolved in response to similar abiotic conditions. Our results are consistent with ecological speciation leading to niche divergence since Coptotermes first arrived in Australia ~12.5 million years ago.

Coptotermes formosanus Shiraki is a wood-feeding termite which secretes a series of lignolytic and cellulolytic enzymes for woody biomass degradation. However, the lignin modification mechanism in the termite is largely elusive, and the characteristics of most lignolytic enzymes in termites remain unknown. In this study, a laccase gene lac1 from C. formosanus was heterogeneously expressed in insect Sf9 cells. The purified Lac1 showed strong activities toward hydroquinone (305 mU/mg) and 2,6-dimethoxyphenol (2.9 mU/mg) with low Km values, but not veratryl alcohol or 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid). Lac1 could function well from pH 4.5 to 7.5, and its activity was significantly inhibited by H2 O2 at above 4.85 mmol/L (P < 0.01). In addition, the lac1 gene was found to be mainly expressed in the salivary glands and foregut of C. formosanus, and seldom in the midgut or hindgut. These findings suggested that Lac1 is a phenol-oxidizing laccase like RflacA and RflacB from termite Reticulitermes flavipes, except that Lac1 was found to be more efficient in phenol oxidation, and it did not require H2 O2 for its function. It is suspected that this kind of termite laccase might only be able to directly oxidize low redox-potential substrates, and the high redox-potential groups in lignin might be oxidized by other enzymes in the termite or by using the Fenton reaction.

Based on prior work, a cellulase from glycosyl hydrolase family 7 (GHF7) was identified and found to be expressed at a high level in Coptotermes formosanus. To determine the function of GHF7 family members in vivo, we used RNA interference (RNAi) to functionally analyse the exoglucanase gene Pseudotrichonympha grassii cellobiohydrolase gene (PgCBH), which was highly expressed in Pseudotrichonympha grassii, a flagellate found in the hindgut of C. formosanus. In this study, the expression level of PgCBH was down-regulated by RNAi, causing the death of P. grassii, but no effect was observed for other flagellates found in C. formosanus. RNAi also resulted in significantly reduced exoglucanase activity, and no effect was observed for endoglucanase and β-glucosidase activities. This result demonstrated that the PgCBH gene plays a role in the protist lignocellulolytic process and is also important for host survival. PgCBH can be used as a target gene and has potential as a bioinsecticide for use against termites.

Miombo woodlands cover extensive areas in southern and southeastern Africa, but are under high anthropogenic pressure. A conspicuous feature of this ecosystem is the presence of high termitaria (>2 m high) built by fungus-growing termites (Macrotermitinae). Despite the fundamental role of termites in African ecosystems, miombo termite communities remain poorly known. We suspected high termitaria to play a structuring role for the whole termite assemblage of miombo woodlands in southern Burundi. In a formerly cleared area, in regeneration since 2009, we expected the termite assemblage to be highly impoverished. The newly growing termitaria of fungus growers might provide suitable bases for recolonisation by soil-feeding species. We recorded 25 species from more than 1000 termite samples. Fungus growers were abundant everywhere. In preserved miombo, high termitaria were home to secondary soil-feeding termite species, seldom encountered in the matrix between mounds. Bushes growing on termitaria also sustained wood-feeding species. The most remarkable feature of the assemblage was the high frequency and diversity of soil-feeding soldierless Apicotermitinae, especially in the matrix. Besides scarce Coptotermes wood feeders, Macrotermitinae were the sole inhabitants of the regenerating area. Our results emphasize the importance of high termitaria for particular soil-feeding species and wood feeders associated with the vegetation growing on termitaria. They raise the question of the ecological factors allowing the coexistence of a rich assemblage of soldierless Apicotermitinae species in the nutrient-poor matrix between mounds. The observations from regenerating miombo confirm the vulnerability of soil-feeding termites to habitat degradation and provide baseline data for future studies of ecosystem restoration.

The distribution and abundance of subterranean termites in Brisbane, Australia, has not previously been investigated, despite the sub-tropical climate being favourable for these xylophagous insects which often cause damage to the built environment. Data on the incidence of termite infestations, including taxonomic identity, locality and site of infestation within premises were collected by a large commercial pest management company in metropolitan Brisbane during a ten-year period (1997 – 2006). General Linear Models based on a negative binomial distribution were used to examine the influence of the climatic variables of rainfall and Southern Oscillation Index (SOI), and the demographic variables of premise density and socioeconomic status, on the number of termite infestations found. Two genera of termites dominated: Schedorhinotermes, which was the most abundant both indoors and outdoors, and Coptotermes. That Schedorhinotermes spp. were the major xylophagous subterranean termites recorded is unique in Australian capital cities where Coptotermes spp. usually dominate. The patterns of abundance and distribution of both genera are discussed with respect to their differing biology. SOI, premise density per ha and household income all significantly explained the variation in termite abundance reported across metropolitan Brisbane over the 10 year study. Our results shows the potential for using SOI as a predictor of termite activity. Further study is needed to more accurately correlate the key drivers of termite activity with the incidence of termite infestations in premises.

Paratransgenesis targeting the gut protozoa is being developed as an alternative method for the control of the Formosan subterranean termite (FST). This method involves killing the cellulose-digesting gut protozoa using a previously developed antiprotozoal peptide consisting of a target specific ligand coupled to an antimicrobial peptide (Hecate). In the future, we intend to genetically engineer termite gut bacteria as "Trojan Horses" to express and spread ligand-Hecate in the termite colony. The aim of this study was to assess the usefulness of bacteria strains isolated from the gut of FST as "Trojan Horses." We isolated 135 bacteria from the guts of workers from 3 termite colonies. Sequencing of the 16S rRNA gene identified 20 species. We tested 5 bacteria species that were previously described as part of the termite gut community for their tolerance against Hecate and ligand-Hecate. Results showed that the minimum concentration required to inhibit bacteria growth was always higher than the concentration required to kill the gut protozoa. Out of the 5 bacteria tested, we engineered Trabulsiella odontotermitis, a termite specific bacterium, to express green fluorescent protein as a proof of concept that the bacteria can be engineered to express foreign proteins. Engineered T. odontotermitis was fed to FST to study if the bacteria are ingested. This feeding experiment confirmed that engineered T. odontotermitis is ingested by termites and can survive in the gut for at least 48 h. Here we report that T. odontotermitis is a suitable delivery and expression system for paratransgenesis in a termite species.

Coptotermes Wasmann (Isoptera: Rhinotermitidae) is one of the most economically important subterranean termite genera and some species are successful invaders. However, despite its important pest status, the taxonomic validity of many named Coptotermes species remains unclear. In this study, we reviewed all named species within the genus and investigated evidence supporting the validity of each named species. Species were systematically scrutinized according to the region of their original description: Southeast Asia, India, China, Africa, the Neotropics, and Australia. We estimate that of the currently 69 named species described by accepted nomenclatural rules, only 21 taxa have solid evidence for validity, 44 names have uncertain status, and the remaining species names should be synonymized or were made unavailable. Species with high degrees of invasiveness may be known under additional junior synonyms due to independent parochial descriptions. Molecular data for a vast majority of species are scarce and significant effort is needed to complete the taxonomic and phylogenetic revision of the genus. Because of the wide distribution of Coptotermes, we advocate for an integrative taxonomic effort to establish the distribution of each putative species, provide specimens and corresponding molecular data, check original descriptions and type specimens (if available), and provide evidence for a more robust phylogenetic position of each species. This study embodies both consensus and contention of those studying Coptotermes and thus pinpoints the current uncertainty of many species. This project is intended to be a roadmap for identifying those Coptotermes species names that need to be more thoroughly investigated, as an incentive to complete a necessary revision process.

Peatlands have experienced large scale changes due to extensive deforestation for logging, conversion to agro-industrial plantations, and frequent peat fires. The adverse effects of peat fires can lead to long-term impacts on invertebrate biodiversity in the peatland ecosystem. Although the impact of fire on termite diversity in tropical grasslands and savannas has been the focus of increased attention in recent years, little is known about the effects of peat fires on termite assemblages. In this review, we present available information about the impact of human use of peatlands on termite assemblages in the Indo-Malayan region. By synthesizing the currently available studies conducted in temperate and tropical savanna systems, we highlight the need for studies of the relationship between termites and fire-impacted tropical peatlands. We consider the ecological and biological scenarios in fire-impacted peatland that are likely to shape termite assemblages, and we discuss traits of the surviving genera (i.e., Coptotermes, Schedorhinotermes, and Parrhinotermes) that may contribute to their success in the harsh post-fire peatland environment (e.g., colony fusion, colony breeding structure, subsidiary nests, and colony migration). Knowledge of these strategies is crucial for understanding the evolutionary adaptation process of termites. This review also aims to stimulate further research in using termite ecosystem services to restore the fertility of degraded fire-impacted peatlands.

Termites were the first animal to form societies. Two hundred million years of evolution provide for a multitude of innate social behaviors that can be experimentally dissected. These fine-tuned patterns of behavior are especially interesting when observing group decision making in the panic mode. In this study, we examined behavioral patterns of termites under panic conditions to gain insight into how an escape flow self-organizes. One hundred worker and 10 soldier Coptotermes formosanus were released into agar plates. After a disturbance was created most workers followed each other and ran along the wall of dishes, thus forming a unidirectional escape flow, whereas soldiers showed a significantly higher frequency of moving to the center of the arena or on periphery of the escape flow as compared to workers. Agonistic behavior was usually observed as soldiers moved to center or periphery. This is the first report on the behavioral repertoire of termites when panicked, with details on the behavioral polymorphism of workers and soldiers during an escape.

Termite baiting is now one of the two main management tools in developed countries after 20 years of commercial release. It has two main goals: to use small amounts of active ingredient and ‘colony elimination’, i.e. death of all individuals in the colony. We consider how well baiting has been evaluated from 100 studies in the scientific literature. Studies have included 15 active ingredients, 23 termite species and 16 countries, yet most studies have focused on the chitin synthesis inhibitor hexaflumuron, Reticulitermes and the United States. Baiting has mostly met its goals: typically about 0.5 g of active ingredient was used, and colony elimination achieved, albeit with rates varying from 0 to 100%, and sometimes supplemented with liquid insecticide. Baiting was most successful using chitin synthesis inhibitors against Reticulitermes and Coptotermes (Rhinotermitidae), in temperate locations, although colony elimination was usually inferred indirectly – mostly by termite absence from baits – and was often slow, from 25 to 450 days. Baiting has been less tested and less successful against higher termites in tropical locations, where they are most diverse and abundant. Future research may have to consider greater termite species diversity and other active ingredients to reduce control times in order to fulfil the potential of baiting. © 2014 Society of Chemical Industry

Although preference and utilization of clay have been studied in many higher termites, little attention has been paid to lower termites, especially subterranean termites. The Formosan subterranean termite, Coptotermes formosanus Shiraki, can modify its habitat by using clay to fill tree cavities. Here, the biological significance of clay on C. formosanus was investigated. Choice tests showed that significantly more termites aggregated in chambers where clay blocks were provided, regardless of colony group, observation period, or nutritional condition (fed or starved). No-choice tests showed that clay had no observable effect on survivorship, live or dry biomass, water content, and tunneling activity after 33-35 d. However, clay appeared to significantly decrease filter paper consumption (dry weight loss). Active particle (sand, paper, and clay) transport behavior was observed in both choice and no-choice tests. When present, clay was preferentially spread on the substrate, attached to the smooth surfaces of the containers, and used to line sand tunnels. Mechanisms and potential application of clay attraction are discussed.

BACKGROUND Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), is a major urban pests in many countries throughout the world. In an attempt to find natural products that could be employed in the effective and environmentally friendly control of the termite, this study investigates, for the first time, the insecticidal activities of the wood and leaf essential oils and ethanolic extracts from Cunninghamia konishii Hayata against C. formosanus according to direct contact application. RESULTS Wood and leaf essential oils and wood ethanolic extract showed the excellent antitermitic activities. Among the four fractions of wood ethanolic extract, the hexane-soluble fraction showed the strongest antitermitic activities. In addition, β-elemol and α-cadinol showed excellent inhibitory action against C. formosanus. CONCLUSION The results clearly reveal that the wood and leaf essential oils and ethanolic extract from C. konishii, and their effective constituents, served as potential, eco-friendly termite-control agents. © 2013 Society of Chemical Industry

Use of proper application methods and formulations of termiticides are important to reduce their negative impact to the environment. In this study, we conducted laboratory experiments to determine the effect of localized treatments with commercial dust and liquid formulations of fipronil against Formosan subterranean termites, Coptotermes formosanus Shiraki. The test arena consisted of a specially designed 16-chambered structure with a center chamber connected to 5 foraging chambers that themselves were connected to 10 additional foraging chambers. One peripheral chamber received a liquid or dust treatment and termites were released in the center chamber. Results showed that >91% of the termites were dead within the 9-d test period despite the localized treatment of only 1 foraging chamber. Termites that were still alive after 9 d were transferred to an untreated dish and held for 10 more days. The majority of those termites were dead and the rest were moribund on day 19. Regardless of the specific dish treated, both formulations of fipronil were found to be highly efficacious. Termites did not exhibit repellency to either formulation. Our results suggest that localized (or spot) treatment with either commercially available dust or liquid formulations of fipronil can be a viable option for control of a termite infestation where complete soil drenching is not desirable.

Background A novel durable termite bait was developed to enable continuous bait availability and lengthen the monitoring interval to 1 year. Laboratory studies were conducted to determine the palatability and insecticidal activity of this bait to Reticulitermes flavipes (Kollar), R. virginicus (Banks), R. hesperus Banks, Coptotermes formosanus Shiraki and Heterotermes aureus (Synder). Results Consumption of the blank durable bait matrix was significantly higher than consumption of a blank preferred textured cellulose matrix (PTC) by R. virginicus, R. flavipes and C. formosanus. R. flavipes, R. hesperus and H. aureus consumed significantly more durable bait than PTC when both contained the active ingredient noviflumuron. All bait treatments resulted in significant mortality relative to the untreated controls. Survivorship of R. virginicus, C. formosanus and H. aureus was 2% or less and not significantly different between the durable bait and PTC treatments containing noviflumuron. The durable bait matrix lagged behind the PTC matrix in mortality over time for all species tested except H. aureus. Conclusion The durable bait was highly palatable and effective in inducing mortality to R. flavipes, R. virginicus, R. hesperus, C. formosanus and H. aureus in the laboratory. This unique bait matrix will be available to termites continuously and allows for an annual monitoring interval. The durability of this bait matrix is unprecedented, allowing for bait to remain active for years and thus providing continuous structural protection.

Symbiotic microorganisms that inhabit the gut of Coptotermes formosanus enablethistermitetodegradelignocellulosesandfurtherproducehydrogenasanimportant intermediate to be recycled in its hindgut or as a byproduct to be emitted to the atmosphere. Both symbiotic protists and prokaryotes in the guts of termites demonstrated some differ- ent roles with respect to hydrogen production. In this study, the effects of two antibiotics, ampicillin and tetracycline, on hydrogen emission and the gut symbionts of C. formosanus were investigated. Hydrogen emission from termite guts was significantly enhanced when termites fed on wood diets treated with either ampicillin or tetracycline. The greatest H2 emission rates, 2 519 ± 74 and 2 080 ± 377 nmol/h/g body weight, were recorded with the treatments of ampicillin and tetracycline, respectively, which showed 6-7 times more H2 productionthanthatofcontrols.Antibiotic-treateddietsnegativelyaffectedtheprokaryotic communitiesandreducedtheirabundances,particularlyonthoseectosymbiontsinhabiting the gut walls or in the gut fluid of C. formosanus, such as spirochetes. However, no signif- icant reductions in the counts of gut cellulolytic protists, Pseudotrichonympha grassii and Holomastigotoids hartmanni, were recorded; and with a further observation by confocal laser scanning microscopy, the endosymbionts inhabiting P. grassii generally survived the antibiotic treatments. These results suggest that some prokaryotes may serve as the main hydrogen consumers, while P. grassii, together with its endosymbionts, may function as the main contributors for hydrogen production in the hindgut of C. formosanus.

Coptotermes formosanus is one of the most destructive wood-feeding termites. To understand the molecular mechanisms that regulate the development of the termite, a normalized C. formosanus cDNA library was constructed using mixed RNA isolated from workers, soldiers, nymphs and alates of both sexes. The sequencing of this library generated 131 636 expressed sequence tags (ESTs) and 25 939 assembled unigenes. The carbohydrate-active enzymes (CAZymes) revealed in this library were analysed in the present report. A total of 509 putative CAZymes were identified. Diverse cellulolytic enzymes were uncovered from both the host termite and from symbionts harboured by the termite, which were possibly the result of the high efficiency of cellulose utilization. CAZymes associated with trehalose biosynthetic and metabolic pathways were also identified, which are potential regulators of the physiological activities of trehalose, an important insect blood sugar. Representative CAZyme coding genes in glycoside hydrolase family 1 (GH1) were quantitatively analysed. The results showed that the five GH1 β-glucosidase genes were expressed differentially among different castes and one of them was female alate-specific. Overall, the normalized EST library provides a comprehensive genetic resource of C. formosanus and will serve a diverse range of research areas. The CAZymes represent one of the repositories of enzymes useful for physiological studies and applications in sugar-based biofuel production.

The establishment of symbiotic relationships with intestinal microorganisms enables termites to thrive on recalcitrant substrates such as cellulose and wood. A termite colony is composed of several different castes which have distinct feeding habits. The soldiers, for example, cannot feed by themselves and depend on workers, who feed them with digested or semi-digested foods. To investigate the influence of feeding habits on the bacterial symbionts, a comparative study of gut bacteria between worker and soldier castes of the termite Coptotermes formosanus was conducted. The bacterial communities of both castes were investigated using denaturing gradient gel electrophoresis (DGGE) and clonal analysis of 16S ribosomal DNA (rDNA). Both methods indicated Bacteroidetes was the common predominant group; the common dominant phylotype was affiliated with a reported uncultured Bacteroidetes phylotype (BCf1–03). There were significant differences in Bacteroidetes and Spirochaetes between two castes. Compared to the gut bacteria of workers, those of soldiers were lower in abundance and diversity of Bacteroidetes and slightly higher in Spirochaetes. Two phylotypes (W8, W11) affiliated to Bacteroidetes and two (W26, W29) affiliated to Spirochaetes were exclusively found in the DGGE profile of the worker caste. Bacteroidetes are assumed to be involved in fermentation of sugars and nitrogenous compounds as well as degradation of uric acid. Spirochaetes are supposed to aid in the functions of acetogenesis and N2-fixation. The different feeding habits between workers and soldiers of C. formosanus may explain the observed differences in the gut bacterial community.

BACKGROUND: Among the termite infestations in the United States, the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), is considered to be the most devastating termite pest. This pest most likely invaded North America as a result of the disembarkation of wooden military cargo at the port of New Orleans that arrived from Asia during and after World War II. It has now spread over other states, including Texas, Florida, South Carolina and California. Devastation caused by C. formosanus in North America has been estimated to cost $US 1 billion a year. Over the pastdecades,organochlorinesandorganophosphates,thetwoprominentclassesoftermitecontrolagents,havebeenbanned owing to environmental and human health concerns. At the present time, phenylpyrazoles, pyrethroids, chloronicotinyls and pyrroles are being used as termite control agents. Mammalian toxicity and seeping of these compounds into groundwater are some of the drawbacks associated with these treatments. The instruction for the application of these termiticides indicate groundwateradvisory.Hence,withtheincreasingspreadoftermiteinfestationthereisanincreasedneedtodiscovereffective, environmentallyfriendly and safe termite control agents with minimal mammaliantoxicity. RESULTS:Chromeneanalogsderivedfromanatural-product-basedchromeneamideisolatedfromAmyristexanaweretestedin acollaborative discoveryprogram foreffective,environmentallyfriendlytermitecontrolagents.Severalchromenederivatives weresynthesizedandcharacterizedasanovelclassofpotentialtermiticides,followedbybioassays.Thesecompoundsexhibited significantly higher mortalities compared with untreated controls in laboratory bioassays. CONCLUSION: Chromene derivatives have been shown to be a potential novel class of termiticides against Formosan subterranean termites. c � 2011 Society of Chemical Industry

Subterranean termites construct complicated tunnel networks for foraging below ground. Thus, they often encounter tunnel intersections during foraging activity. Directional selection by termites at intersections is likely to affect foraging efficiency because depending on their selection, the path length from food resources to the nest can vary significantly. In order to understand how termites are guided to choose the most economical path without the use of pheromones, we artificially excavated two tunnels of varying widths (W1 and W2; 2, 3, or 4 mm) that intersected at a 90° angle in each of nine soil-filled arenas. We observed the directional selection of termites at intersections in arenas with combinations of W1 (mm) and W2 (mm) (W1, W2). For (W1, W2) = (2, 2) and (4, 4), termites statistically equally chose the three directions left, right, and straight, while for the (3, 3) arena combination, termites preferentially decided to go straight. On the other hand, for (W1, W2) = (2, 3) (2, 4), and (3, 4), termites advancing from narrower tunnels into intersections tended to turn right or left, while termites coming from the wider tunnel were more inclined to go straight. On the assumption that a wider tunnel is more frequently used by termites in the field, we can deduce that the wider tunnel may represent the most efficient/shortest path. Thus, this simple selection mechanism can prevent termites from deviating from the most economical path.

Reports on the capability of wood-feeding termites (WFTs) in degrading wood particles and on the existence of aerobic environment in the localized guts suggest that their high efficiency of cellulose utilization is not only caused by cellulase, but also by biochemical factors that pretreat lignin. We thus extend the hypothesis that for highly efficient accessibility of cellulose, there should be direct evidence of lignin modification before the hindgut. The lignin degradation/modification is facilitated by the oxygenated environment in intestinal microhabitats. To test our hypothesis, we conducted experiments using a dissolved oxygen microelectrode with a tip diameter < 10 μm to measure oxygen profiles in intestinal microhabitats of both Coptotermes formosanus (Shiraki) and Reticulitermes flavipes (Kollar). Lignin modification during passage through their three gut segments was also analyzed with pyrolysis gas chromatography/mass spectrometry. The data showed relatively high levels of oxygen in the midgut that could have promoted lignin oxidation. Consistent with the oxygen measurements, lignin modifications were also detected. In support of previously proposed hypotheses, these results demonstrate that lignin disruption, which pretreats wood for cellulose utilization, is initiated in the foregut, and continues in the midgut in both termites.

Hydrogen emission by wood-feeding termites, Coptotermes formosanus, Reticulitermes flavipes and Reticulitermes virginicus, was investigated upon a cellu- losic substrate as their food source. The emission rates among the three species tested were significantly different and R. virginicus demonstrated the greatest H2 emission at 4.78 ± 0.15 μmol/h/g body weight. In a sealed test apparatus, H2 emission for each ter- mite species showed a quick increase at the initial incubation hours (3-6 h), followed by a slower growth, possibly due to the feedback inhibition by gas accumulation. Further investigation revealed that continuous H2 emission could be maintained by reducing the H2 partial pressure in the sealed container. The bioconversion of cellulose to molecular H2 by the subterranean termites tested could reach as high as 3858 ± 294 μmol/g cellu- lose, suggesting that the termite gut system is unique and efficient in H2 conversion from cellulosic substrate.

BACKGROUND:CoptotermesformosanusShirakiwasaccidentallyintroducedintotheUnitedStatesfromAsia.Theintroduction of the pest has brought significant economic consequences. During the past decade, Mississippi has become a significantly infested state, partly due to the proximity to coastal port cities such as New Orleans. This study was initiated to investigate the origin and infestation route of C.formosanusin southern Mississippi. RESULTS: Twenty-eight colonies (21 colonies from Mississippi, six from Louisiana, one from China) were collected. Sequencing and analysis of 112 sequences revealed 15 haplotypes of cytochrome oxidase subunit II (COII) gene in the world. Two haplotypesofCOIIwereidentifiedinMississippi.Inaddition,specificprimersweredesignedandtesteddifferentiallytoamplify characteristic fragments for verifying and surveying different genotypes ofC.formosanusin the future. CONCLUSION: Of the two haplotypes identified in Mississippi, the GA group was identical to those reported previously in Georgia, Louisiana, Alabama and other infested states. The second haplotype, the AT group, was identified for the first time in southeastern United States. Sequence identity of the AT-group C. formosanus with those reported mainly in southeastern Asian countries provided evidence of at least two introductions of C.formosanusinto the United States. c � 2010 Society of Chemical Industry

A scent-trail pheromone from a Pakistani termite, Coptotermis heimi (Wasmann) has been isolated and characterised to be an unsaturated diterpenoid hydrocarbon, C20H32O. Progressive chromatographic refinement has given a fraction that demonstrates the presence of a volatile chemical that can influence the general behaviour of Coptotermis spp. The material which is hexane soluble and relatively stable acted both as a “trail-following substance” and sex-related pheromone and both the sexes respond equally to it. Zusammenfassung Ein Spurlegungspheromon bei der pakistanischen Termite Coptotermis heimi (Wasmann) Bei Coptotermis heimi wurde ein Spurlegungspheromon isoliert und als ein ungesattigtes Diter-penoidhydrocarbon (C20H32O) charakterisiert. Die progressiv-chromatographische Verfeinerung ergab eine Fraktion, deren Duftkomponente das Verhalten von Coptotermis beeinfluβt. Die in Hexan losliche und relativ stabile Substanz wirkte gleichzeitig als Spur- und Sexualduft, und zwar auf beide Geschlechter.

Optimal temperature of feeding activity of different termite species The wood consumption of termite groups was recorded at constant temperature intervals of 2° C and the condition of the groups was determined after certain test periods, mostly 4, 8, 12 und 16 weeks. The termite species investigated were of the Termitidae Nasutitermes nigriceps (Haldeman), Nasutitermes arborum (Smeathman), Microcerotermes crassus Sny-der and Microcerotermes championi Snyder, the Rhinotermitidae Prorhinotermes simplex (Hagen), Coptotermes amanii (Sjostedt), Coptotermes formosanus (Shiraki), Coptotermes niger Snyder, Reticulitermes speratus (Kolbe) with the geographical races speratus, lepto-labralis and kyushuensis Morimoto, Reticulitermes virginicus (Banks), Reticulitermes flavi-pes (Kollar) with groups of different locations, Reticulitermes lucifuges (Rossi) with groups from Portugal, Spain, France (Corsica), Italy, Yugoslavia and Greece and furthermore Reticulitermes santonensis De Feytaud, the Termopsidae Zootermopsis angusticollis (Hagen) and Zootermopsis nevadensis (Hagen), the Kalotermitidae Neotermes castaneus (Burmeister), Neotermes jouteli (Banks) and Incisitermes tabogae (Snyder) and Mastoter-mitidae Mastotermes darwiniensis Froggatt. The optimal temperature for wood consumption of these and other termite species investigated earlier in the same way, in total 25, was found to be between about 33° C and about 22° C. Differences in the reaction to temperatures do not only exist between species of different climatic regions but also between species of the same area of distribution. Geographical races of the same species may differ in their reaction to temperatures or may react equally. The culturing temperature maintained before the test may influence the temperature at which the highest rate of wood consumption is observed. During long periods the optimal temperature may remain constant, may decrease or may increase slightly. For survival and colony development lower temperatures may be more favourable than for wood consumption. Differences in the optimal temperature were stated not only with termites from different climatic regions, but also with species of the same area and the same genus. The knowledge of the optimal temperature for wood consumption is useful for culturing and testing termites in the laboratory. Zusammenfassung Bei konstanten Temperaturstufen im Abstand von je 2° C wurde der Holzfras von Termitengruppen nach mehreren Versuchszeiten (meist 4, 8, 12 und 16 Wochen) sowie der Zustand der Gruppen nach Versuchsende bestimmt. Die verwendeten Termiten-Arten waren von Termitidae Nasutitermes nigriceps (Haldeman), Nasutitermes arborum (Smeath-man), Microcerotermes crassus Snyder und Microcerotermes championi Snyder, von Rhi-notermitidae Prorhinotermes simplex (Hagen), Coptotermes amanii (Sjostedt), Coptoter-mes formosanus (Shiraki), Coptotermes niger Snyder, Reticulitermes speratus (Kolbe) mit den geographischen Rassen speratus, leptolabralis und kyushuensis Morimoto, Reticulitermes virginicus (Banks), Reticulitermes flavipes (Kollar) mit Tieren verschiedener Her-kunfte, Reticulitermes lucifugus (Rossi) mit Tieren aus Portugal, Spanien, Frankreich (Korsika), Italien Jugoslawien und Griechenland sowie Reticulitermes santonensis De Fey-taud, von Termopsidae Zootermopsis angusticollis (Hagen) und Zootermopsis nevadensis (Hagen), von Kalotermitidae Neotermes castaneus (Burmeister), Neotermes jouteli (Banks) und Incisitermes tabogae (Snyder) und von Mastotermitidae Mastotermes darwiniensis Froggatt. Die Optimaltemperatur fur den Holzfras dieser und in entsprechender Weise fruher untersuchter, insgesamt 25 Termiten-Arten liegen zwischen rd. 33° C und rd. 22° C. Unterschiede im Verhalten gegenuber der Temperatur bestehen nicht nur zwischen Arten aus verschiedenen Klimabereichen, sondern auch zwischen Arten gleichen Verbreitungs-gebiets. Geographische Rassen einer Art konnen sich in ihrem Verhalten gegenuber der Temperatur unterscheiden oder auch gleich sein. Die vorangehende Zuchttemperatur kann die Hohe der Temperatur, bei der am meisten gefressen wird, beeinflussen. Wahrend lange-rer Versuchszeiten kann die Optimal-Temperatur gleich bleiben oder niedriger oder etwas hoher werden. Fur Uberleben und Kolonieentwicklung konnen niedrigere Temperaturen gunstiger sein als fur die Frasaktivitat. Unterschiede in der Optimal-Temperatur treten nicht nur bei Termiten aus verschiedenen Klimagebieten, sondern auch bei Arten gleicher Herkunft und der gleichen Gattung auf. Die Kenntnis der optimalen Temperatur fur den Holzfras ist fur Zucht und Prufungen im Laboratorium nutzlich.

Here are presented bioecological and economical observations on termites of Peninsular India, especially as regards ecological habitats, mound- and nest-structure, the economic damage caused to forest trees, etc., made on 25 species belonging to 2 families (Rhinotermitidae and Termitidae) and the following 14 genera: Heterotermes, Coptotermes, Eremotermes, Microcerotermes, Angulitermes, Dicuspiditermes, Procapritermes, Labiocapritermes, Macrotermes, Odontotermes, Microtermes, Emersonitermes, Nasutitermes and Trinervitermes. The study area covered an extent of roughly 22 400 km2 (Tamil Nadu 400 km2, Kerala 9000 km2, and Karnataka 13 000 km2). Mounds and/or nests are described in several species. Microcerotermes minor causes 20–30% mortality in Eucalyptus citriodora plantations, and Odontotermes horni at least 10% mortality in Eucalyptus spp., in both cases by girdling tap roots. Mounds of Odontotermes brunneus, O. obesus and O. wallonensis, and carton nests auf Microcerotermes fletcheri and Nasutitermes brunneus, are discussed. The mound and nest of Trinervitermes biformis are described. Zusammenfassung Biookologische und okonomische Beobachtungen an Termiten der Halbinsel Indien Es wurden Beobachtungen uber die im Sudteil Indiens verbreiteten Termiten mitgeteilt, speziell was die Habitats, die Bauten- und Neststrukturen sowie den Schaden an Baumen und anderem betrifft. 25 Arten werden in die Betrachtungen einbezogen. Sie gehoren zu 2 Familien (Rhinotermitidae und Termitidae) sowie 14 Gattungen: Heterotermes, Coptotermes, Eremotermes, Microcerotermes, Angulitermes, Dicuspiditermes, Procapritermes, Labiocapritermes, Macrotermes, Odontotermes, Microtermes, Emersonitermes, Nasutitermes und Trinervitermes. Das Untersuchungsareal umfaste die Gebiete von Tamil Nadu, Kerala und Karnataka mit zusammen 22 400 km2. Microtermes minor verursachte 20–30% Schaden in Eucalyptus-citridora-Plantagen, Odontotermes horni mindestens 10% bei Eucalyptus spp. in beiden Fallen durch Ringelung der Hauptwurzel. Die Bauten von Odontotermes brunneus, O. obesus und O. wallonensis, sowie die Kartonnester von Microcerotermes fletcheri und Nasutitermes brunneus werden naher betrachtet. Der Bau und das Nest von Trinervitermes biformis werden beschrieben.

Antitermitic properties of extracts from five Brazilian hardwoods were investigated in tests with the Formosan subterranean termite. Woods were extracted sequentially with hexane, acetone, a 54:44:2 acetone-hexane-water (AHW) mixture, and 80 % methanol. These extracts were tested for toxic, repellent, antiprotozoan, and antifeedant properties. Antitermitic properties varied with wood and solvent and, in some cases, with concentration of extract. Termite feeding and corresponding survival on the extract-treated absorbent paper pad were high for only a few extracts. Volatile constituents of Cedrela odorata and Ocotea cymbarum were termiticidal, and greatest repellency was evident for the hexane, acetone, and AHW extracts of these two species. Abnormally low protozoan numbers were found in termites surviving for 4 weeks on 11 extracts. Termites generally preferred untreated paper to extract-treated paper in a choice test for antifeedant properties. Some paper was not consumed but used by the termites in their carton-building activities. Zusammenfassung Reaktionen von Coptotermes formosanus Shiraki auf die Extrakte von 5 brasilianischen Hartholzern Es wurden antitermitische Eigenschaften von Extrakten aus 5 brasilianischen Hartholzern gegenuber der Formosa-Termite C. formosanus untersucht. Die Holzextrakte wurden mit Hexan, Aceton, Aceton-Hexan-Wasser (AHW 54:44:2) sowie 80%igem Methanol hergestellt. Diese Extrakte wurden hinsichtlich ihrer Gift-, Repellent-, Antiprotozoen- sowie Frasabschreckungs-wirkung getestet. Die antitermitischen Eigenschaften variierten mit der Holzart, dem Losungsmittel und in manchen Fallen mit der Extraktkonzentration. Der Termitenfras und das Uberleben der Termiten auf der mit dem Extrakt behandelten Fliespapierunterlage waren nur bei einigen wenigen Extrakten hoch. Fluchtige Bestandteile von Cedrela odorata und Ocotea cymbarum erwiesen sich als termitizid, wobei die Hexan-, Aceton- und AHW-Extrakte die besten Wirkungen zeigten. Abnorm niedrige Protozoenzahlen wurden in solchen Termiten gefunden, die 4 Wochen lang unter Einwirkung von 11 Extrakten uberlebten. In einem Auswahlversuch zogen die Termiten generell das unbehandelte Papier dem mit Extrakt behandeltem vor. In einigen Fallen wurde das behandelte Papier nicht verzehrt, sondern zum Bau von Kartonnestern verwendet.

Synopsis Notes are given on three indigenous and one introduced species of Coptotermes present in the Ethiopian Region, and keys provided to assist in their identification. Their systematic position is discussed, and their geographical distribution illustrated.

This study evaluates the synergistic effect of wood extractives and quaternary ammonium compounds (QACs) on the resistance to termites of several treated wood species. Wood specimens from different natural durability classes were extracted with either hot water alone or hot water + ethanol/benzene. The extracted and unextracted wood specimens were treated with either didecyldimethylammonium tetrafluoroborate (DBF) or commercial didecyldimethylammonium chloride (DDAC) solutions and then exposed to subterranean termites, Coptotermes formosanus Shiraki, for 3 weeks under laboratory conditions. The results showed that extractives of the heartwood portions of the wood species contributed to increased resistance against termite attack in the presence of either DBF or DDAC wood preservatives. The synergistic effect of wood extractives and DBF was much clearer with Pseudotsuga menziesii (Mirbel) Franco and Tsuga heterophylla Sarg wood samples. Further studies are needed for a better understanding of the synergism between wood extractives and either DBF or DDAC using both the sapwood and heartwood portions of the same wood species.

An isolate of Paecilomyces fumosoroseus was obtained from Coptotermes formosanus collected in Hong Kong, and a commercially available isolate of Metarhizium anisopliae, were both tested against C. formosanus shipped live from China. Survivorship of termites treated with a suspension of 5 x 10 5 M. anisopliae conidia/ml and kept alone declined more rapidly than for those treated at the same concentration of P. fumosoroseus conidia. At a 5 x 10 6 conidia/ml concentration, no significant differences in terms of termite survivorship were observed between the two fungal species. However, among termites kept in groups of 10 after treatment, those sprayed with P. fumosoroseus conidia at either 5 × 10 5 or 5 × 10 6 conidia/ml had significantly lower survivorship than those sprayed with M. anisopliae conidia. All the cadavers of termites treated with P. fumosoroseus and kept alone sporulated and among grouped termites 29% of the cadavers sporulated. By comparison, 53% of the cadavers of termites treated with M. anisopliae and kept alone sporulated, and only 4% of the cadavers of treated termites kept in groups sporulated.

Termites are among the most important cellulose-digesting animals on earth, and are well-known for the symbiotic relationship they have with cellulolytic trichomonad and oxymonad flagellates (unicellular eukaryotes). Perhaps less well-known is the fact that approximately 75% of the approximately 2600 described termite species -- those belonging to the family Termitidae -- do not harbour such flagellates. Unlike most termites from other families, the majority of termitids do not consume wood, feeding instead on soil, leaf litter, fungi, grass, or lichen. Recent years have seen the characterization of the endogenous cellulase enzymes that help termites digest cellulose, from one flagellate-harbouring species (Reticulitermes speratus), as well as one termitid (Nasutitermes takasagoensis). The genes encoding the enzymes in these two termites are similar. However, their site of expression differs markedly -- the salivary glands in R. speratus and the midgut in N. takasagoensis. To investigate this difference further, we performed a comparative study of cellulase expression in various termitid and flagellate-harbouring species, using enzyme assays and reverse transcription polymerase chain reactions. Taxa from phylogenetically basal lineages were consistently found to express endogenous genes specifically in the salivary glands, whilst those from a relatively apical lineage containing termitids expressed cellulases solely in the midgut. Relatively low levels of cellulase activity were found in nonwood-feeding species, while the wood-feeding Coptotermes formosanus -- arguably the most destructive pest species world-wide -- was found to have high levels of activity in all parts of the gut when compared to all other termites. In the light of these results, as well as recently accumulated phylogenetic data, we discuss scenarios for the evolution of cellulose digestion in termites.

In laboratory tests, 2'-acetonaphthone was incorporated into sand at different concentrations (4.16-200 mg kg(-1)) and evaluated for survivorship, feeding and tunneling effects on the Formosan subterranean termite, Coptotermes formosanus Shiraki. 2'-Acetonaphthone at 8.33 mg kg(-1) sand significantly reduced survivorship (89-94%), tunnel area (68-91%) and food consumption (84-100%) compared with the control. Most of the dead workers were found at the release point and a few had traveled to the surface of the treated sand. Malformed workers (< or =27%) with an unexpected symptom of molting failure were observed, particularly at the lowest concentration tested (4.16 mg kg(-1)). In choice assays, threshold concentration for significant reduction in survivorship, tunnel construction in treated sand and food consumption in the treated-sand side was 8.33mg kg(-1) with termites collected from New Orleans, LA and 35.0 mg kg(-1) for those from Lake Charles, LA. Termites actively fed and tunneled in the untreated sand, whereas 2'-acetonaphthone at 140mg kg(-1) completely inhibited consumption of food placed on the treated sand.

The Formosan subterranean termite, Coptotermes formosanus Shiraki is currently one of the most destructive pests in the USA. It is estimated to cost consumers over US dollars 1 billion annually for preventative and remedial treatment and to repair damage caused by this insect. The mission of the Formosan Subterranean Termite Research Unit of the Agricultural Research Service is to demonstrate the most effective existing termite management technologies, integrate them into effective management systems, and provide fundamental problem-solving research for long-term, safe, effective and environmentally friendly new technologies. This article describes the epidemiology of the pest and highlights the research accomplished by the Agricultural Research Service on area-wide management of the termite and fundamental research on its biology that might provide the basis for future management technologies. Fundamental areas that are receiving attention are termite detection, termite colony development, nutrition and foraging, and the search for biological control agents. Other fertile areas include understanding termite symbionts that may provide an additional target for control. Area-wide management of the termite by using population suppression rather than protection of individual structures has been successful; however, much remains to be done to provide long-term sustainable population control. An educational component of the program has provided reliable information to homeowners and pest-control operators that should help slow the spread of this organism and allow rapid intervention in those areas which it infests.

Strains of the entomopathogens Beauveria bassiana (Balsamo)Vuillemin and Metarhizium anisopliae (Metschnikoff)Sorokin were screened for effectiveness against the Formosan subterranean termite, Coptotermes formosanus (Shiraki). Biological control methods are being considered to augment current integrated pest management schemes that involve chemical baits and nonrepellent termiticides. In this study Formosan subterranean termites selected from four colonies in the field were exposed in the laboratory to three strains of Beauveria bassiana and two strains of Metarhizium anisopliae. The exposed termites were then allowed to mingle with an equal number of unexposed termites from the same nest and mortality of the combined group was determined. One week after exposure, B. bassiana strains, ATCC 26037 and ATCC 90519, had caused significantly higher mortality than the two M. anisopliae strains, ESC 1 and II B and the remaining strain of B. bassiana, ATCC 90518. The LT50 measurement for strains 26037 and 90519 was comparable at 1.8 and 2.0 days, respectively. Strains ESC 1 and 90518 caused 50% mortality at 6.5 and 11.0 days, respectively. Termites exposed to strain II B and the control group of termites did not reach 50% mortality during the 21 day experimental period. Exposure of termites to all fungal strains resulted in mortality in excess of that seen in the control groups of unexposed termites.

The potential of vetiver oil and nootkatone as wood treatments against Coptotermes formosanus Shiraki was examined by assessing the effects on termite tunneling, feeding activity and survival, and the consequences on the symbiont protozoa responsible for wood digestion. Comparisons were made with non-treated wood (control), wood treated with the borate compound Tim-Bor® (a commonly used lumber preservative) and absence of a food source (starved termites), using choice and no-choice tests. All wood slices were prepared at the same time using a 10 g liter−1 solution of each substance and were tested in four different sessions over one year to investigate longevity of the effects. Termites had to tunnel through sand to exploit the food sources, consisting of two wood slices, placed on opposite sides of the experimental enclosure. No-choice tests showed that in the presence of vetiver oil or nootkatone, tunneling activity was always the lowest; wood consumption, termite survival and flagellate numbers and species distribution were significantly different from the control and similar to the results obtained for starved termites and with Tim-Bor–treated wood. Nootkatone negatively affected termites for 12 months and was longer lasting than vetiver oil. In choice tests, when vetiver oil or nootkatone were present, termites exhibited a significant preference for non-treated wood. Our results confirmed both the toxicity and absence of repellency of Tim-Bor®. Vetiver oil and especially nootkatone affected Formosan subterranean termites and their protozoa, acting as arrestants, repellents and feeding deterrents, and represent a promising natural alternative for the control of this invasive pest. © 2002 Society of Chemical Industry

Coptotermes formosanus workers were treated topically with insecticide and subsequently held individually or in groups to examine possible effects on insecticide toxicity. Chlorpyrifos, cypermethrin and chlordane toxicities were 1.4-, 1.5-, and 1.3-fold greater, respectively, among workers held in groups compared with those held individually after insecticide treatment. Experiments were conducted to examine how enhanced toxicity occurred among termites held in groups after topical insecticide treatment. When workers were treated topically with chlordane and immediately placed with untreated workers, significantly greater numbers of untreated workers were killed compared with controls at all ratios examined (insecticide-treated:untreated). These data indicated that workers treated topically with insecticide were capable of somehow transferring a lethal dose of insecticide to untreated workers confined in the vial. Chlordane was recovered from untreated workers which had been confined with chlordane-treated workers; significantly higher quantities of chlordane were recovered from dead workers exposed to chlordane-treated workers compared with surviving workers exposed to chlordane-treated workers. Possible mechanisms of insecticide transfer from insecticide-treated to untreated termites are discussed.

Laboratory experiments with three species of termites were conducted to study the efficacy of a carbamate derivative of 2-(4-hydroxybenzyl)-1-cyclohexanone (W-328). The compound has been found to be highly active causing differentiation of termite workers into presoldiers, soldiers and/or soldier-intercastes. Differentiation of excessive soldiers induced by juvenile hormone analogues (JHAs) may disrupt the social homeostasis and consequently cause death of the whole termite colony. W-328 induced differentiation into soldiers in 41-100% of individuals when applied in range of 50-500 ppm to a feeding substrate of wood in force-feeding and choice bioassays with groups of Reticulitermes santonensis Feytaud and R. flaviceps (Oshima). Efficacy of W-328 was also confirmed in choice bioassays with isolated groups of workers and soldiers and with incipient colonies of Coptotermes formosanus Shiraki. A high proportion of JHA-induced differentiation into soldier caste was accompanied by increased mortality. Termites accept a matrix treated with W-328 quite well. Significant feeding deterrence of the compound was observed only at higher concentrations: 500 ppm in some tests with Reticulitermes spp. and 5000 ppm in colonies of C. formosanus. Adequate persistence of W-328 in corrugated cardboard (a potential feeding substrate for baits) was confirmed by bioassay with R. santonensis and by chemical analysis. The residue levels of the compound, applied at 500 ppm concentration, after 27 days of conditioning remain high enough to result in significant soldier differentiation.

1. Forager population size of two species of mound-building, subterranean termite (Coptotermes lacteus, Rhinotermitidae and Nasutitermes exitiosus, Termitidae) was estimated using three mark–recapture protocols. These estimates varied widely within and between colonies (≈ 0.3–200 million for C. lacteus and 0.2–3 million for N. exitiosus). The variation in the estimates is explained in part by violation of the assumptions of the protocols. 2. The fat-stain markers, although persistent in the laboratory, faded rapidly in the field, and were transferable from marked individuals to unmarked individuals by cannibalism. 3. Marked individuals did not mix randomly or evenly with unmarked foraging individuals in space or time, as marked individuals were recaptured in widely varying numbers at different feeding sites sampled simultaneously. Importantly, foragers displayed feeding site fidelity and avoided disturbed feeding sites. 4. The likelihood of recapture differed between castes and instars; there was a higher recapture rate of large workers and soldiers relative to smaller workers. 5. The mark–recapture protocols provided inaccurate and unreliable forager population estimates, up to two orders of magnitude larger than direct counts of entire mound colonies. Thus the weighted mean estimates from more complex triple-mark–recapture protocols were not necessarily better than Lincoln index estimates from simpler single-mark–recapture protocols. 6. Mark–recapture studies may provide useful information about forager behaviour and foraging territories.

Formosan subterranean termites, Coptotermes formosanus Shiraki, were exposed to ⩾ 95% or 50% carbon dioxide atmospheres for intervals of 24-120 h at 26(±3)°C. A 24-h exposure to ⩾ 95% carbon dioxide caused significant termite mortality, but 60 h were required for complete mortality. Exposure to 50% carbon dioxide for 60 h resulted in approximately 70% termite mortality, while complete mortality was recorded after 120 h. When termites were sealed in wooden blocks (90 × 90 × 152 mm), 72-96 h exposure to ⩾ 95% carbon dioxide was necessary for complete control. A limited study with Cryptotermes brevis (Walker) suggested that this drywood termite is also susceptible to carbon dioxide fumigation, although slightly longer exposures may be required than with C. formosanus. Carbon dioxide-modified atmospheres are a viable alternative to conventional fumigants for vault fumigation of termite-infested materials, and may also be applicable to larger-scale fumigations to control structural pests.

A laboratory choice test was developed to assess the efficacy and acceptability of sporulating strains of Beauveria bassiana (Balsamo) Vuillemin and Metarhizium anisopliae (Metsch.) Sorokin to foraging Formosan subterranean termites, Coptotermes formosanus Shiraki. Filter paper disks were saturated with agar media and inoculated with either B. bassiana strain 787 or 3041, or M. anisopliae strain 346, 472 or 2162. Filter papers containing eight-day-old cultures were rolled into cylinders with the sporulating culture on the inside of the cylinder, and placed in one of two plastic jars, connected by a glass tube. Termites were placed in the other jar (refugia), and allowed to forage throughout both jars. This apparatus simulates the use of a fungal bait for subterranean termite control in the field. Termites did not avoid contact with the fungal baits, and fed upon the agar-treated filter papers. Exposure to M. anisopliae strains 346 and 2162 resulted in rapid termite mortality while exposure to the B. bassiana strains caused slower, but escalating, mortality. Efficacy of the fungi was not affected by the degree of sterility of the termite tunnelling medium. Living cultures of entomopathogenic fungi hold promise for further development as baits for subterranean termite control.

1 Native Reticulitermes spp. Holmgren and the introduced Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) were exposed to predation in the laboratory by Solenopsis invicta Buren (Hymenoptera: Formicidae), a known predator of Reticulitermes. 2 In one experiment, both taxa contained the 2.4% soldiers commonly found in Reticulitermes. In a second experiment, Reticulitermes contained 2.4% and C.formosanus a more normal 18.3% soldiers. 3 When soldier proportions were equal, C.formosanus soldiers suffered less of a decrease in survivorship due to predation compared with Reticulitermes soldiers. Little difference was found between taxa in the effect of predation on termite workers or in the effect of termites on predator survivorship. 4 When soldier proportions were unequal, both C.formosanus castes suffered less from predation than those of Reticulitermes. Again, little difference was found in the effect of termites on ants. 5 C.formosanus showed less movement into new containers when soldier number was abnormally low, compared with both taxa with normal caste proportions.

The insecticidal effects of Lantana camara L. (flowers, leaves, stems and roots) and the soil where lantana had been growing, on foraging activity and survival of the subterranean termites Coptotermes formosanus and Reticulitermes flavipes were examined in a 3-week experiment. The soil in which lantana had been growing had no effect on termite tunneling and survival. Incorporation of chipped fresh lantana leaves and stems into soil had no effect on mortality but caused significant reduction in tunneling. The 5-cm wide barrier of soil with lantana tissue incorporated effectively repelled groups of both species from penetrating the barrier and thus prevented infestation of a piece of wood on the other side of the barrier. C. formosanus was more sensitive in avoiding the barrier than R. flavipes. Leaves, stems and flowers were more repellent than roots. These results provide preliminary evidence that fresh-cut lantana leaves, stems and flowers may have use as additives to garden mulches against termites.

BACKGROUND: Research has shown that the family of grapefruit flavors called nootkatones have significant repellant and toxic effects to Formosan subterranean termites (Coptotermes formosanus Shiraki). RESULTS: Nineteen synthetic nootkatone derivatives, along with three commercially available nootkatone derivatives, were tested for repellent activity against C. formosanus by a choice assay in a petri dish with a two-step triage procedure. Based on the repellency threshold value, the relationships between structure and activity are discussed. CONCLUSION: Four derivatives of nootkatone have very high repellency and toxicity to C. formosanus, 9 times the potency of the primary compound nootkatone. Four other compounds have between 2 and 3 times the repellency of nootkatones, and three compounds are equal in their repellency to nootkatone.

Effects of the new insecticide silafluofen (HOE 084498) on tunneling and survival of Formosan subterranean termites, Coptotermes formosanus Shiraki, were determined in both forced-exposure and indirect-exposure laboratory bioassays. In the indirect-exposure assays, termites were given the option of tunneling through sand treated with an emulsifiable formulation of silafluofen to reach a supplemental food source. Although C. formosanus tunneling was reduced in sand containing 10 ppm silafluofen, this concentration did not cause significant mortality in the forced-exposure assay. Forced exposure to 100 ppm silafluofen killed all termites within 24 h. In tunneling assays, 500 ppm silafluofen was required to prevent complete termite penetration through the 7.5 cm tunneling arena, and ≥ 1000 ppm to limit tunneling distances to 1 cm or less. In topical application assays, a 5% dust formulation of silafluofen proved extremely toxic to C. formosanus workers, and may be useful for treatment of termite galleries within wood. Zusammenfassung Laborversuche uber die Wirkung des neuartigen Bodeninsektizids Silafluofen auf die Formosa-Termite Coptotermes formosanus Shir. (Isopt., Rhinotermitidae) Bei Versuchen mit partiell (streckenweise) mit flussigem Silafluofen kontaminiertem Sandboden bewirkten alle Konzentrationen des Wirkstoffs eine Reduktion der Wuhltatigkeit der Termite, doch waren 100 ppm und mehr notwendig, um eine 7,5 cm dicke Erdschicht vor der Durchtunnelung zu bewahren. Erst Konzentrationen von 1000 ppm und mehr schutzten eine 1 cm breite Erdschicht vor der Durchtunnelung, so das diese Konzentration notwendig erscheint, um im Freiland die erdwuhlende Termite von dem Angriff auf ein Nahrungssubstrat abzuhalten. Bei topikaler Applikation fuhrten 5% Silafluofen-Staub zur vollstandigen Vernichtung der Termite, so das diese Form der Applikation sich zur Bekampfung des Schadlings in Holztunnels eignen durfte.

The hemolymph of each caste of the primitive dampwood termite Zootermopsis nevadensis (Isoptera, Termopsidae, Termopsinae) contains a high molecular mass lipoprotein which functions as a specific, high affinity carrier for juvenile hormone (JH) III, as detected by JH III-displaceable covalent modification by the tritium-labeled photoaffinity analog (10R)-10, 11-epoxyfarnesyl diazoacetate ([3H]EFDA). The Formosan termite Coptotermes formosanus (Rhinotermitidae, Coptotermitinae) and Eastern subterranean termite Reticulitermes flavipes (Rhinotermitidae, Rhinotermitinae) possess analogous proteins. Variations among the major proteins and the JH-binding lipoproteins are described.