Search Results (27)

Termites of the genus Coptotermes are among the most destructive structural pests worldwide, owing to their efficient lignocellulose degradation and metabolic adaptability mediated in part by cytochrome P450 enzymes. Although numerous botanical compounds have been reported to exhibit termiticidal activity, mechanistic in silico studies targeting detoxification-related enzymes in Coptotermes, particularly cytochrome P450, remain limited. In this study, twenty-eight plant-derived bioactive compounds were evaluated using an integrated in silico framework comprising insecticide likeness screening, molecular docking, toxicity prediction, environmental fate assessment, and molecular dynamics simulation. Homology modeling enabled structural characterization of cytochrome P450 from C. formosanus, and subsequent screening identified 27 compounds with favorable physicochemical and ADMET properties. Molecular docking analysis highlighted Glyceollin, Cnicin, Biochanin A, Ferruginol, and ent-kaur-16-en-19-oic acid as strong binders, exhibiting stable interactions with conserved active-site residues. Toxicological and ecological assessments indicated generally low predicted risk to mammals, birds, and pollinators, while identifying potential sensitivity in aquatic organisms, emphasizing the need for controlled application. Molecular dynamics simulations further supported the stabilizing effect of Glyceollin on cytochrome P450 under simulated conditions. Overall, the study provides mechanistic insight into botanical inhibition of cytochrome P450 in Coptotermes and identifies promising candidate compounds for further experimental validation in sustainable termite management strategies. Full article

Previous studies have demonstrated that Trichoderma metabolites triggered aggregation behavior in Coptotermes formosanus (Blattodea: Rhinotermitidae). Building on this, the present work systematically evaluated the behavioral effects of three specific Trichoderma metabolites—phenol, ethyl 2,4-dioxovalerate, and diglycolic acid—and their synergistic interactions with insecticides. We hypothesized that these metabolites attract C. formosanus through multiple behavioral mechanisms and enhance the toxicity of insecticides. Bioactivity showed that ethyl 2,4-dioxovalerate and diglycolic acid exhibited no significant toxicity. Phenol (5 × 10⁻² to 5 µg/cm) and ethyl 2,4-dioxovalerate (5 × 10⁻¹ µg/cm) elicited trail-following behavior. In the no-choice insecticide synergy test, phenol or diglycolic acid combined with imidacloprid (50 µg/g) resulted in substantially higher mortality compared to insecticides alone. The combination of metabolites with fipronil resulted in 100% mortality in termites. In two-choice aggregation tests, termite presence on metabolite-treated filter papers was significantly elevated compared to the controls. Fipronil (10 μg/g) alone significantly reduced termite aggregation. But when fipronil was combined with the metabolites, termite presence on the treated papers increased significantly, resulting in a substantial rise in mortality and demonstrating a clear attract–kill synergy. These findings identify Trichoderma metabolites as safe and effective behavioral regulators for C. formosanus. By enhancing insecticidal efficacy through attractant–toxicity synergy, they represent promising candidates for developing novel termite control strategies. Full article

Obligate symbionts often exhibit some degree of co-speciation with their hosts. One prominent example is the symbiosis between termites and their wood-feeding hindgut protists. This symbiosis is mutually obligate, vertically inherited by anal feeding, and it predates the emergence of termites from their cockroach ancestors. Termites and their symbiotic protists might therefore be expected to have congruent phylogenies, but symbiont loss, transfer, and independent diversification can impact the coevolutionary history to varying degrees. Here, we have characterized the symbiotic protist communities of eight Neoisoptera species from three families in order to gauge the phylogenetic congruence between each lineage of protists and their hosts. Using microscopy and 18S rRNA gene sequencing of individually isolated protist cells, we identified protists belonging to the Parabasalia genera Pseudotrichonympha, Holomastigotoides, Cononympha, and Cthulhu. Pseudotrichonympha were present in all of the investigated termites, with a strong pattern of codiversification with hosts, consistent with previous studies. The phylogeny of Holomastigotoides indicates several instances of diversification that occurred independently of the hosts’ diversification, along with lineage-specific symbiont loss. Cononympha occurs only in Heterotermitidae and Psammotermes. Surprisingly, the small flagellate Cthulhu is widespread and exhibits cophylogeny with its hosts. This study demonstrates that different symbiont lineages can show different coevolutionary patterns, even within the same host. Full article

The eastern subterranean termite, Reticulitermes flavipes, is challenged by the significant energy expenditures of tunnel construction for resource discovery. Subterranean termites use idiothetic mechanisms to explore large spaces, while the use of resource-specific cues for localized search is disputed. Here, termite response to wood mulch, termite workers, extracts of wood mulch, and CO₂ alone were tested using a bioassay design that distinguished between attraction and arrestment. Termites showed significant attraction to wood mulch with workers or to wood mulch alone. They did not respond to workers alone at the initial dose tested, but were attracted to workers at higher densities. Termites did not respond to water or the acetone extracts of wood mulch, but did show a partial response to hexane extract compared to intact wood mulch. More significantly, when CO₂ was removed from the emissions of wood mulch and workers using soda lime, attraction was eliminated. Furthermore, termites showed a quadratic response to CO₂ concentration that peaked at ca. 14,000 ppm. The response to CO₂ alone predicted by the model matched termite response to mulch + workers when compared at the level of CO₂ they emitted. The results suggest that CO₂ is both necessary and sufficient to explain the attraction response of R. flavipes to mulch and workers we observed. It is argued that orientation to food cues complements the previously demonstrated idiothetic program to maximize the efficiency of resource location. Full article

We examined the distribution of termites along an elevational gradient in the western Rif Mountains of northern Morocco. Sampling followed standardized protocols at nine forest sites (125, 325, 488, 715, 850, 1150, 1316, 1544, and 1700 masl), all except the lowest site within the Intercontinental Mediterranean Biosphere Reserve. We found a total of three termite species, with Reticulitermes grassei (Rhinotermitidae) being the most abundant, followed by Kalotermes flavicollis (Kalotermitinae) and Amitermes sp. (Terminidae). Comparing microhabitat preferences, we found R. grassei and Amitermes sp. exclusively in buried wood and under rocks, and K. flavicollis exclusively in dead tree trunks and surface wood. The findings reveal the distribution of microhabitats along an elevation gradient and the corresponding preferences of termite species across these microhabitats. We found that total termite density decreased significantly with elevation (r_s = −0.40; p < 0.001), but with distinct differences among species. Kalotermes flavicollis and Amitermes sp. showed a strong negative correlation between density and elevation. In contrast, for R. grassei, the most common termite, we found no significant correlation. Termite density also varied among forest types, with a non-significant trend (p = 0.075) of higher density in the cork oak forest (hits/m² = 0.06) compared to holm oak (0.04) and fir–cedar (0.02) forests. This research contributes to the limited knowledge of termite diversity and ecology in northern Africa and western Mediterranean forests. Full article

High-risk termites in wood imported to the Republic of Korea are currently treated with methyl bromide (MB), which has ozone-depleting properties and is highly toxic. This study evaluated the effectiveness of sulfuryl fluoride (SF) as a quarantine treatment against Reticulitermes speratus Kolbe (Blattodea: Rhinotermitidae) in wood, along with its wood sorption and penetration capacity. The LCt₅₀ and LCt₉₉ values for SF were 30.87 and 42.53 mg h/L at 23 °C and 151.62 and 401.9 mg h/L at 5 °C, respectively. The SF Ct values did not significantly differ between dry and wet wood at loading ratios of 10%, 30%, and 50% at both 5 °C and 23 °C (p > 0.05). In a closed wooden cube, the LCt₅₀ and LCt₉₉ for SF for R. speratus were 31.59 and 53.34 mg h/L, respectively, indicating an excellent wood penetration ability. SF caused 100% termite mortality with a 90% loading ratio in the scale-up trials (500 L). The SF concentration during ventilation decreased below the threshold limit value (TLV) of 5 ppm within 30 min, confirming that the working conditions were safe. This study provides a basis for the use of SF as an alternative to MB for the treatment of termites in wood. Full article

Subterranean termites of the species Reticulitermes speratus kyushuensis Morimoto (Isoptera: Rhinotermitidae) are notoriously destructive soil-dwelling pests that feed on the cellulosic wood biomass. This leads to tremendous losses of forest trees such as Pinus densiflora Siebold and Zucc. (Pinales: Pinaceae) and precious wooden structures of cultural heritage. This study investigated the efficacy of chitinase and protease produced by Bacillus licheniformis PR2 as cuticle-degrading enzymes for the biocontrol of worker termites. Bacillus licheniformis PR2 produced a strong chitinase and protease activity up to a maximum of 82.3 unit/mL and 35.9 unit/mL, respectively, and caused a lethal effect on termites under laboratory conditions. Treatment of termites with the bacterial broth culture and the crude enzyme fraction of B. licheniformis PR2 resulted in a maximum mortality rate (with a median lethal time (ET50)) of 83.3% (3 h, 36 min) and 88.9% (2 h, 59 min), respectively. The termites treated with B. licheniformis PR2 exhibited loss of setae, disintegration of epicuticle, rupturing of procuticle, and swelling at sockets. The degradation of cuticular chitin and glycoprotein polymers in the termite cuticle by chitinase and protease enzymes produced by B. licheniformis PR2 represents an effective eco-friendly strategy for controlling termite damage in Korean cultural heritage sites and forests. Full article

Termites are eusocial insects that live in organized colonies consisting of reproductives, workers, and soldiers. Soldiers are specialized for defense but are expensive to maintain, as they are incapable of husbandry and must be fed and groomed by workers. The soldiers of several species influence foraging behavior by acting as scouts that initiate foraging or by mediating worker behavioral plasticity during food exploration. These behaviors imply that soldiers may play a keystone role in termite colony function, apart from defense. Subterranean termite workers tunnel through soil in search of food while accompanied by varying proportions of soldiers, depending on the species and colony conditions. Previous studies have shown that soldiers accelerate worker exploratory tunneling behavior in two Reticulitermes species, the colonies of which contain fewer than 2% soldiers. This effect, however, is unknown in other subterranean species with different soldier proportions. In this study, we examined the influence of soldiers on exploratory foraging behavior in the Formosan subterranean termite, Coptotermes formosanus Shiraki, which is an economically devastating invasive species that maintains a relatively high soldier proportion (about 10%). When 100 foraging workers were grouped with 0, 2, 10, or 30 soldiers in two-dimensional foraging arenas, we found no significant effect of soldiers on the tunnel length, branch pattern, food source interception, or food collected within 96 h. These results suggest that C. formosanus colonies maintain food exploration efficiency regardless of soldier proportion variation. Full article

Rhinotermitid termites, serious pests of wooden structures throughout the world, are commonly controlled with chitin synthesis inhibitor bait systems. Seasonal termite foraging patterns in some regions may prolong bait interception time, however, significantly decreasing colony elimination speed. We hypothesized that installing baits immediately prior to the season of highest foraging activity will minimize interception time when baiting for Reticulitermes spp. in California, a region characterized by a hot-summer Mediterranean climate. To test this theory, we installed three different bait systems on four dates corresponding to the major seasons (spring, summer, autumn, winter) at five field locations known to harbor the target species. We then recorded initial termite discovery events every 60 days for two years, considering effects of installation season, bait system, site, and distance from previously observed termite incidence on bait interception time. Observed foraging activity in bait stations was highest during late winter and spring. Baits installed during winter exhibited interception times more than 100 days shorter than those of baits installed during summer. From these findings, we conclude that colony elimination speed and perceived CSI bait utility may be increased in Mediterranean climate regions when baits are installed immediately prior to the wet season. Full article

Based on behavioral observations, we report termitophily by the earwig Spirolabia kaja Kočárek, sp. nov. (Spongiphoridae: Labiinae). The new species was found in association with the wood-boring termite Schedorhinotermes sarawakensis (Holmgren, 1913) in a dipterocarp rain forest in Borneo; in addition to being observed in the galleries, termite–earwig interactions were subsequently documented in the laboratory. We found that earwigs and termites communicate by antennation, and we observed no form of targeted mutual or unilateral aggressive behavior. The earwigs responded to the proximity of an experimentally irritated termite soldier by conflict-avoidance behavior based on thanatosis, which seems to be a defensive reaction that may reduce the chance of being attacked by an irritated termite. Based on the analysis of gastrointestinal tract contents, we conclude that S. kaja sp. nov. is an omnivorous species that feeds mainly on plant tissues and fungi but occasionally on arthropod remains. The occurrence of S. kaja sp. nov. adults together with the nymphs (2nd to 4th instars) in the galleries of S. sarawakensis strongly suggests that the earwig can reproduce inside the termite colony. Spirolabia kaja Kočárek, sp. nov. is the first earwig species for which termitophily has been demonstrated. Full article

This work assesses damage caused by Coraebus undatus (Fabricius) (Coleoptera: Buprestidae) and Reticulitermes grassei Clément (Blattodea: Rhinotermitidae) in managed cork oak forests from the southern Iberian Peninsula. Lesions were diagnosed and quantified in relation to the following features: height and orientation in the trunk, diameter at breast height, solar exposure, understory presence and orography. The distribution patterns of lesions in the study area across 12 plots and in the trunk of the trees were also analyzed. The study was performed in “S^a de Hornachuelos” Natural Park (Córdoba, Spain) and the research area encompassed 12 environmentally-restored sampling plots. Data were recorded from 2007 to 2014, with yearly sampling from late June to mid-September, corresponding to the cork extraction period, since lesions caused by these insects are well distinguishable promptly after bark removal. The results reveal that C. undatus has low population levels and a non-uniform distribution pattern in the study area as well as in the trunk of the tree. It shows preference for medium height but not by any trunk orientation. R. grassei also shows low infestation levels and a preference to affect the trunk’s base. Comparatively, C. undatus showed higher infestation levels than R. grassei. The location of damage was also different, since galleries made by C. undatus predominated at intermediate trunk heights while those of R. grassei were more frequent at lower heights. Our results further showed a low co-occurrence of both species in the same tree trunks, which could be explained in terms of overlapping in the distribution areas of both species. These results provide background information that will enable natural resources managers to detect changes and trends of these species and inform future management decisions. Full article

Linear and geometric morphometrics approaches were conducted to analyze the head capsule (HC) shape of collected soldier caste specimens of Coptotermes from various locations in Indonesia. The soldiers’ morphology was observed and measured. The results of the principal component analysis of the group of all species showed two important groups of variables, i.e., the body size and setae characteristics of the pronotum and head. The multicollinearity of the morphometric variables showed the importance of body measurements as well as important alternative characteristics such as the pronotum setae (PrS) and HC setae. Four trends of HC shape were observed across the species. Interestingly, three extreme shapes were depicted by geometric morphometrics of the C. gestroi HC. The phylogenetic tree inferred from 12S and 16S mitochondrial gene fragments showed high confidence for C. gestroi populations. The lateral expansion of the posterior part of the HC across the species was in accordance with the increasing of the number of hairlike setae on the pronotum and HC. These differences among species might be associated with mandible-force-related defensive labor and sensitivity to environmental stressors. Full article

Coptotermes gestroi (Wasmann) (Blattodea: Rhinotermitidae) is a subterranean termite species from Southeast Asia which has been unintentionally introduced to many parts of the world through commerce and modern transportation. Known for causing extensive damage to timber used in the built environment, the termite also has a habit of nesting in carton nests in wood and wooden structures in buildings. As so little is known of its breeding system, colony, and genetic structure, we initiated work to sequence its genome with an Illumina HiSeq™ 2000 sequencer. In this publication, we announce our paired-end sequencing data and report the isolation of 119,190 microsatellite markers from our DNA assembly. The microsatellite marker reported in this publication can be used to elucidate the mating system and genetic structure of this highly invasive termite species. Additionally, in this announcement the study authors make the Bio Project sequence accession number SRR13105492 accessible from the Sequence Read Archive database. Full article

Effective active ingredients in toxicant bait formulations must be non-deterrent to insect feeding behavior at lethal concentrations. This study evaluated feeding deterrence for Coptotermes formosanus Shiraki, C. gestroi (Wasmann), and Reticulitermes flavipes (Kollar) when provided access to cellulose impregnated with various concentrations of the insect molting hormone, 20-hydroxyecdysone (20E). Termites were exposed to 20E concentrations of 200, 500, 1000 and 2000 ppm and to noviflumuron at 5000 ppm in a 24 h choice-test, and the mass of substrate consumption from treated and untreated media pads was compared for each treatment. 20E feeding deterrence was detected at 500, 1000 and 2000 ppm for C. gestroi, and at 2000 ppm for C. formosanus. No significant differences in consumption of treated and untreated substrate was detected at any concentration for R. flavipes. Potential methods for reducing deterrence are discussed. Full article

Termite infestations in urban areas are a serious problem because they cause negative economic effects, reduce the esthetic value of buildings, damage crops, and require household repairs. Chemical controls are the most common method used against subterranean termites, and baiting has emerged as one of the prominent control methods. The goal of this research was to determine the efficacy of termite baiting by treating one of six active termite stations (selective baiting) with chlorfluazuron baits to eradicate six populations of subterranean termites. This work shows that the placement of chlorfluazuron baits in one of the active stations was sufficient to destroy a colony that was interconnected with multiple chlorfluazuron-free stations. In general, it requires an average of 4–8 weeks for a quantity of less than 300 g of chlorfluazuron bait to remove a termite infestation at the study site. Full article