Exploring the diversity of microbes and natural products from fungus-growing termite tripartite symbiosis

The fungus-growing termite is considered a distinct ecological niche because it involves a tripartite symbiosis between the termite host,gut microflora,and the in vitro fungus Termitomyces,which has led to the expansion of highly organized and complex societies among termite colonies.Tripartite symbiosis in fungus-growing termites may promote unique microbes with distinctive metabolic pathways that may serve as valuable resources for developing novel antimicrobial therapeutic options.Recent research on complex tripartite symbioses has revealed a plethora of previously unknown natural products that may have ecological roles in signaling,communication,or defense responses.Natural products produced by symbionts may act as crucial intermediaries between termites and their pathogens by providing direct protection through their biological activities.Herein,we review the state-of-the-art research on both microbes and natural products originated from fungus-growing termite tripartite symbiosis,highlighting the diversity of microbes and the uniqueness of natural product classes and their bioactivities.Additionally,we emphasize future research prospects on fungus-growing termite related microorganisms,with a particular focus on their potential roles in bioactive product discovery。

Comparison of gut-associated and nest-associated microbial communities of a fungus-growing termite （Odontotermes yunnanensis）

The digestion of cellulose by fungus-growing termites involves a complex of different organisms, such as the termites themselves, fungi and bacteria. To further investigate the symbiotic relationships of fungus-growing termites, the microbial communities of the termite gut and fungus combs of Odontotermes yunnanensis were examined. The major fungus species was identified as Termitomyces sp. To compare the micro-organism diversity between the digestive tract of termites and fungus combs, four polymerase chain reaction clone libraries were created （two fungus-targeted internal transcribed spacer [ITS] - ribosomal DNA [rDNA] libraries and two bacteria-targeted 16S rDNA libraries）, and one library of each type was produced for the host termite gut and the symbiotic fimgus comb. Results of the fungal clone libraries revealed that only Termitomyces sp. was detected on the fungus comb; no non-Termitomyces fungi were detected. Meanwhile, the same fungus was also found in the termite gut. The bacterial clone libraries showed higher numbers and greater diversity of bacteria in the termite gut than in the fungus comb. Both bacterial clone libraries from the insect gut included Firmicutes, Bacteroidetes, Proteobacteria, Spirochaetes, Nitrospira, Deferribacteres, and Fibrobacteres, whereas the bacterial clone libraries from the fungal comb only contained Firmicutes, Bacteroidetes, Proteobacteria, and Acidobacteris.

Termite Attack and Damage in Cocoa Plantations in Daloa Department, Central-Western Côte d’Ivoire

Cocoa farming faces numerous constraints that affect production levels. Among these constraints are termites, one of the biggest scourges in tropical agriculture and agroforestry. The aim of this study is to assess the level of damage caused by termites in cocoa plantations. To this end, 3 plantations were selected. In each of the 3 plantations, 18 plots containing an average of 47 ± 6 cocoa plants were delimited. Sampling was based on 25 cocoa plants per plot. The study consisted in sampling the termites observed on the plants and noting the type of damage caused by them, taking into account the density of the harvest veneers and, above all, the termites’ progress through the anatomical structures of the plant, i.e. the bark, sapwood and heartwood. A total of 8 termite species were collected from cocoa plants. These species are responsible for four types of damage (D1, D2, D3 and D4), grouped into minor damage (D1 and D2) and major damage (D3 and D4). D1 damage ranged from 24.67% ± 5.64% to 39.55% ± 7.43%. D2 damage ranged from 6.88% ± 1.31% to 9.33% ± 2.79%. D3 damage ranged from 2.88% ± 1.55% to 6.44% ± 1.55%. D4 damage ranged from 1.11% ± 1% to 3.11% ± 1.37%. Among the termite species collected, Microcerotermes sp, C. sjostedti, A. crucifer and P. militaris were the most formidable on cocoa trees in our study locality. In view of the extensive damage caused by termites, biological control measures should be considered, using insecticidal plants.

Evaluation of the Efficacy of Essential Oil Extracts in the Control of Termites (Isoptera: Termitidae) in Cashew Orchards in Badikaha (Côte d’Ivoire)

Cashew tree has gradually moved from a purely ecological aspect to a socio-economic one, due to the marketing of its nuts. But production per area, estimated at between 424 and 547 kg/ha, remains low, in contrast to India (2nd largest producer) and Vietnam (3rd largest producer), whose yields range from 1000 to 1500 and 2000 to 2500 kg/ha respectively. This low yield is due to a number of factors, among which insect pests are the most damaging. Among these insects, termites are considered to be one of the main pests of cashew trees. The general objective of this study is to contribute to termite management through the use of bioinsecticides, an alternative to the use of chemicals in cashew orchards. Five (5) biological products were tested: Limocide, Carapa oil, Neem oil, Kitana and Kaskara. Among them, two products proved effective, with a mortality rate of over 50%. These were Limocide, whose LC50 was obtained in 24 h at a dose of 3.6 g/ml and 3.1 g/ml , giving a mortality rate of 57.66% ± 4.04% and 51.33 ± 2.08 respectively , and Carapa, at a dose of 4.5 g/ml, with an estimated mortality rate of 52.33% ± 1.52%. Such results have demonstrated the potential application of Limocide and Carapa biopesticides to sustainably control termites in cashew orchards of Côte d’Ivoire.

西非Termit盆地石油地质特征及成藏主控因素

西非Termit盆地是中国石油在非洲极为重要的勘探开发区块。在充分利用钻井、分析化验和地震资料基础上,开展了Termit盆地石油地质特征和成藏主控因素研究,研究表明:①Ter-mit盆地历经前裂谷期、同裂谷期、后裂谷期三大构造演化阶段,同裂谷期发育早晚两期裂谷作用形成中生代—新生代叠置裂谷盆地,宏观具有“东西分带、南北分块”的构造结构特征,控制圈闭的形成与分布。②发育上白垩统Yogou组分布广(18000 km^(2))、厚度大(600~1400 m)、成熟度适中(Ro值为0.7%~1.3%)的海相烃源岩,配置上白垩统Yogou组顶部发育的海相三角洲、古近系Sokor1组辫状河三角洲砂体,及古近系Sokor2组区域性分布的泥岩盖层,形成了上、下两套成藏组合;③明确古近系、白垩系成藏主控因素,古近系为“下生上储”的次生油气藏,油气平面和垂向分布受生烃灶、区域盖层、油源断层和优势沉积相控制,白垩系为“自生自储”原生油藏,油气富集受区域构造活动强度和白垩系内幕构造控制。④构建了基于海相广覆式烃源岩的跨世代油气成藏模式,明确Dinga断阶带、Fana凸起和Araga地堑是古近系油气勘探的有利区带,造活动相对较弱的Moul凹陷及Dinga断阶带南部是白垩系油气勘探的有利区带。地质认识指导勘探部署,在尼日尔Termit盆地获得了重大勘探突破,累计探明石油地质储量超7亿t,为中国石油海外油气增储上产奠定了坚实的基础。

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

The entomopathogenic fungus Isaria fumosorosea Wize, formerly known as Paecilomyces fumosoroseus is reported as a promising biocontrol agent for controlling subterranean termites, particularly those belonging to the family Rhinotermitidae. In Malaysia, the family Rhinotermitidae includes two species of subterranean termites with extremely high economic importance; namely Coptotermes curvignathus Holmgren, and the Asian SLubterranean Termite (Coptotermes gestroi Wasmann). To comprehend the potential control of this soil-dwelling fungus against these subterranean termites in Malaysia, an investigation was carried out by testing the pathogenecity of 11 isolates against these termite species. All isolates showed pathogenic potential against the termite (Mortality rate of C. curvignathus:84.4%; C. gestroi:67.3%). IsolatePF49 was the most effective against both species of termites and was further tested for its virulence and mycosis.The LC_(50) values of PF49 against C. curvignathus and C.gestroi were 7.55×103 and 1.09×102 conidia/ml,respectively. The average number of days required to complete the mycosis process in C. curvignathus and C.gestroi were 4.7 and 8 days, respectively. These fungi are believed useful for protecting living trees, plants, wood,wood structures, and other cellulosic materials susceptible to termite infestation and damage.

A New Fossil Termite (Isoptera,Stolotermitidae,Stolotermes) from the Early Miocene of Otago,New Zealand

The forewing of a termite from Early Miocene lake sediments in Otago, southern New Zealand is figured and described. It exhibits the generic characters of the damp-wood termite Stolotermes Hagen, but differs from forewings of the known species in size and venation pattern and is described as Stolotermes kupe sp. nov. S. kupe represents the first confident record of fossil Stolotermitidae and extends the fossil record of the family back to the Early Miocene. It also is the first direct evidence of fossil Isoptera from New Zealand, though silicified termite faecal pellets, referable to Kalotermes brauni, have been previously described. S. kupe indicates that Stolotermitidae has been present in the Australasian region since at least the Early Miocene.

Effects of Selected Pesticidal Plants on Termites Affecting Maize Production in Arusha, Tanzania

Investigations under laboratory and field conditions were carried out with purpose of understanding the effects of pesticides of Cupressus lusitanica, Tephrosia vogelii, Eucalpytus dalrympleana, Lantana camara and Azadirachta indica in the control of termites which affect maize production in Arusha, Tanzania. Termites were collected before and during maize season of 2018 and identified at the Tropical Pesticides Research Institute (TPRI) laboratory. A total of 5279 out of 5307 termite species identified belong to genus Macrotermes, 23 species to genus Odontotermes and 5 species were unknown. The results entailed that the area is rich in species of genus Macrotermes. Moreover, concentrations i.e. 5 g, 10 g and 20 g of each botanical were tested for Macrotermes spp. mortality and repellency ability in the laboratory using a completely randomized design (CRD) with three replicates. The results showed that 98.33% Macrotermes spp. mortality was caused by T. vogelii followed by 93.33% recorded from E. dalrympleana after 24 hours. Besides, C. lusitanica repelled Macrotermes spp. by 97% followed by 95% recorded from T. vogelii and E. dalrympleana each. For field trials, 20 g of each botanical was applied using randomized complete block design (RCBD) with four replicates. The results obtained from field indicated that T. vogelii was more effective to protect maize with an average of 6 maize stands and 3.4 kg of dry total weight of maize grains next to positive control per plot. Also, average of 4 maize stands and 3 kg dry total weight of maize grains were recorded from treatments of E. dalrympleana and C. lusitanica each. Such results highlight the potential of developing bio-termiticides from T. vogelii, C. lusitanica and E. dalrympleana to control Macrotermes spp.

Effect of transferring lignocellulose-degrading bacteria from termite to rumen fluid of sheep on in vitro gas production, fermentation parameters, microbial populations and enzyme activity

The digestive tract of termite(Microcerotermes diversus) contains a variety of lignocellulose-degrading bacteria with exocellulases enzyme activity, not found in the rumen, which could potentially improve fiber degradation in the rumen. The objectives of the current study were to determine the effect of inoculation of rumen fluid(RF) with three species of bacteria isolated from termite digestive tract, Bacillus licheniformis, Ochrobactrum intermedium, and Microbacterium paludicola, on in vitro gas production(IVGP), fermentation parameters, nutrient disappearance, microbial populations, and hydrolytic enzyme activities with fibrous wheat straw(WS) and date leaf(DL) as incubation substrate. Inoculation of RF with either of three termite bacteria increased(P<0.05) ammonia-N concentration compared with the control group(free of termite gut bacteria). Termite bacteria inoculation had no effect(P>0.05) on gas production characteristics, dry matter, organic matter and neutral detergent fiber disappearance, pH, and concentration and composition of volatile fatty acids. Population of proteolytic bacteria and protozoa, but not cellulolytic bacteria, were increased(P<0.05) when RF was inoculated with termite bacteria with both WS and DL substrates. Inoculation of RF with termite bacteria increased protease activity, while activities of carboxymethyl-cellulase, microcrystalline-cellulase, α-amylase and filter paper degrading activity remained unchanged(P>0.05). Overall, the results of this study indicated that transferring lignocellulose-degrading bacteria, isolated from digestive tract of termite, to rumen liquid increased protozoa and proteolytic bacteria population and consequently increased protease activity and ammonia-N concentration in vitro, however, no effect on fermentation and fiber degradation parameters were detected. These results suggest that the termite bacteria might be rapidly lysed by the rumen microbes before beneficial effects on the rumen fermentation process could occur.

Characteristics of termite mounds and associated Acrisols in the coastal savanna zone of Ghana and impact on hydraulic conductivity

Characteristics of termite mounds and associated Rhodic Acrisol and Haplic Acrisol in the coastal savanna zone of Ghana and their impact on hydraulic conductivity were assessed. The texture of the mounds was sandy clay in contrast to the sandy clay loam of the surface soils. Translocation of fine to medium sized soil materials influenced the relatively higher bulk density (>1.60 Mg/m3) and contents of organic carbon, nitrogen and exchangeable bases in the mounds. Kaolinite was the dominant clay mineral with pH values generally below 5.3 in all the soils reflecting the weathered tropical soil environment. Dispersion ratio values, which were 0.5 for the surface soils, indicated greater stability of the mound due to aggregate cementing action by the termites. Estimated mound density was about 120 mounds per ha, which tied in with known groundwater reserves at the study sites. Majority of the mounds exhibited a cone-shaped morphology with heights varying between 3.05-4.00 m in the Rhodic Acrisol and 2.05-4.20 m in the Haplic Acrisol with corresponding estimated total mass of 96,361 kg and 54,910 kg per 1000 m2 land area. These estimates represented a large amount of material relative to the 25,000-26,000 kg of surface soil material within the same unit area. The K in the surface soils ranged from 3.3 x 10-5 to 5.0 x 10-5 m/s while the value for the mound was ≤0.5 x 10-5 m/s. Lower porosity, θ;the effect was more pronounced when the mound was applied on the soil surface. Improvement in water retention and nutrient availability to plants and prevention of leaching to avoid groundwater contamination are some of the positive attributes of this study.

Analysis of Feed Preference of Edible Termites (Isoptera) on Selected Plants and Their Crude Extract Phytochemistry

Termites are social insects that inhabit colonies in the soil. Termites feed on a wide range of plants found within diverse habitats of Luanda Sub-County. This study aimed at assessing feed preference of edible termites and analyzing their phytochemical composition. Termites were exposed to ten different test plants in their natural habitats to assess feed preference. Forty-seven study sites were selected as they had high termite abundance from previous studies. The test plants were Grevillea robusta, sugarcane, maize, blue citronella grass, Eucalyptus, mango, avocado, neem, bamboo and a mixture of all the ten plants. Small pits were dug in the ground where the ten treatments were placed and replicated four times each. The test plants were placed in the evening then covered with soil block. The number of termites feeding on the test plants was counted after 12 hours the following day. There were separate trials for crushed and uncrushed feed substrates. The feed substrates that showed high feed preference was selected for phytochemical analysis. The plants whose crude extract was obtained were Grevillea robusta, bamboo, Eucalyptus, cypress, maize and sugarcane. The results for this study were analysed using one-way ANOVA. The study revealed that crushed feed substrates had a high level of feed preference by termites p < 0.05. The mixture of all the feed substrates also showed high termite preference and a mean and SE of 676.500 ± 41.7a. Phytochemical analysis of the crude plant extracts revealed that Eucalyptus had the highest number of phytochemicals present 9 out of 12. The identified phytochemicals were saponins, tannins, alkaloids, resins, cardiac glycosides, carbohydrates, phenols and flavones.

Geotechnical Characterization of Termite Mound Soils of Congo

This study is to determine the activities and correlations in the fundamental properties of the termite mounds soils Cubitermes spp and Macrotermes sp. The Intrinsic properties depend on the mineralogy, organic composition and texture of soil. Grain size, Atterberg limits and soil blue values are geotechnical properties that were used to characterize the two soils. On the basis of the geotechnical properties, specific surface area, cation exchange capacity, relative activity, surface activity and soil activity were determined. The correlations obtained in the intrinsic soil properties are linear and polynomial fits. Indeed, the relationship between the plasticity index and the blue value of a soil on the one hand and between the specific surface area and the cation exchange capacity on the other hand, is a linear fit for all soils in general. The relationship between plasticity index and specific surface area is a linear fit for the soils (C, M). Correlations in intrinsic soil properties that have a coefficient of determination close to 1 can be used in geotechnical engineering to predict one of the two desired parameters.

Assemblages and species diversity of wood destroying termites in different land use systems in Western Ghat, India

Spatial distribution, abundance and assemblage of termites depend mainly on the local conditions and habitats in which they thrive. Striking differences are observed in the species richness, number of clades and functional diversity of termite assemblage between different habitats. This study aim was to examine effect of human interference in the diversity of wood destroying termite in forest areas as well as managed and unmanaged plantations in South India. Termites attacking trees and wooden logs were collected from forest areas, managed plantations and unmanaged plantations. The termites collected were identified and compared for species abundance, richness and species diversity. Results show that the species composition and species diversity of the wood destroying termites vary according to the conditions. The species diversity measures revealed that there is a significance variation among the forest fauna and plantations. The forest areas have the highest species composition compared to plantations. Species richness is high forest areas. Even though the abundance of termites are more in unmanaged plantations, there is no significant difference related to species diversity among the managed and unmanaged plantations.

Rural households' livelihoods diversification through termite utilization in depressed region of Zimbabwe

This study sought to examine the utility of termites to rural households in depressed regions of Bikita,Zimbabwe.Colonialism and its spread of European culture had viewed entomophagy with contempt resulting in reduced utilization and consumption of termites in most colonies.In our quest to understand how people in depressed regions utilized termites,both quantitative and qualitative methodologies were employed.Questionnaires and in-depth interviews were used to gather data during field work.Purposive and snowball sampling techniques were used in recruiting respondents.Excel and content analysis were used in data presentation and analysis.Results revealed that dampwood and drywood termites are climatic indicators for the rural communal farmers,a low-cost technology in weather forecasting.Subterrain and mold builders provide manure,relish,and are medicinal in nature.They are traded for income generation,and as for the poor,harvesting,processing,storage,and marketing is cost effective.Though considered nostalgic foods,most respondents highlighted that selling termites complimented other off-farm livelihood activities.Termite consumption and utilization provide a sustainable way for livelihood diversification in depressed regions and has partly addressed problems of food insecurity.

Research Progress of Termite Control with Fipronil

The indoor and field control effect of fipronil against termite was introduced, and the main influencing factors were analyzed, including traverse transfer of fipronil between termite individuals, temperature and proportion of termite exposed to fipronil, synergistic effect of other agents on fipronil, diffusion and degrada- tion of fipronil in soil. The effects of fipronil and metabolites on environment were elaborated.

Electrical Performance and Effect of Frequency Electromagnetic Waves on Subterranean Termites <i>Coptotermes curvignathus</i>Holmgren

The research aimed to propose a non-destructive technology to control subterranean termites Coptotermes curvignathus Holmgren infestation based on electromagnetic waves. A portable apparatus for this technology has been built and its experiment is presented in this paper. Some electrical parameters were measured and analyzed along with their effects to the termites. The experiment using frequency range between 30 Hz - 600 kHz has been done. The average error of the apparatus by comparing the result with the direct measurement using oscilloscope was also measured. The highest error value appeared at 600 kHz with frequency error 6.05 kHz. The highest error of voltage (i.e. 0.186 Volt) appeared at 100 kHz. For safetiness, the highest magnetic field at 300 kHz was 0.1815 μT and at 500 kHz was 0.00725 μT which were safe for human. The average value of termites mortality was higher on irradiation time 120 minutes than 60 minutes respectively in all test frequency: 300 kHz, 400 kHz, 500 kHz and 600 kHz. This paper presents an important information of the electromagnatic-based technology for environmental friendly termites control in spite of using the insecticides.

Investigation on Preventive Treatment of Termite in Landscape Plants of Central Park

This paper had investigated the termite hazard of garden plants in Shanghai Songjiang Central Park with 71 plants of trees destroyed by termites and two control groups as tested varieties. These 71 plants of trees would be treated by using the treatment of toxicity soil combined with powder, the first control group would be treated by anti-termite powder, and the second group would be given no treatment. After 50 days'treatment, it was found that the treatment rate of toxicity soil combined with powder was 93%, with stable effect and no repeatability; the treatment rate of anti-termite powder was 33.3%, with unstable effect and repeatability, and it was needed to change and add medicament again and again so as to make sure that trees would no longer be damaged by termite; there still existed termite hazard in the second group without treatment. By contrasting different treatment methods, it could be known that treatment of toxicity soil combined with powder had obvious advantage, harmless to human body and environment, and could replace traditional medicaments and methods with strong toxicity.

Polyethism in Termites

Polyethism or division of works among workers of social insects is always a hot issue among entomologists. Honey bees, ants, and wasps are the main target for scientists to study the division of works. Studying polyethism in termites has been increased recently due to the damages to the forests, buildings, boats and even water preserving monuments. Every year a huge amount of money is spent to control these isopteran social insects in the south east of Asia, the US, Australia and other tropical and subtropical regions. As understanding the polyethism in these social insects can be a hand in controlling them, in this review we have tried to explain different kinds of polyethism and their importance in these social insects.

Natural Resistance of Two Plantation Woods Populus × canadensis cv. and Cunninghamia lanceolata to Decay Fungi and Termites

Natural durability of two plantation woods, Chinese fir and I-214 poplar, was investigated thoroughly by three test- ing methods, namely an accelerated laboratory decay test, a fungus cellar test and a field test. After the decay test using Postia pla- centa and Trametes versicolor, Chinese fir and the I-214 poplar showed 34% and 69% of mass loss, respectively, indicating they should be classified as slightly durable and non-durable wood. This conclusion was confirmed by the fungus cellar test and the field test. Like the performance in the decay test, I-214 poplar showed no resistance to termites either in the laboratory or in the field, whereas Chinese fir would be classified as moderately resistant.

Geochemistry of Termite Hills as a Tool for Geochemical Exploration of Glass Sand in the Iraqi Western Desert

Sand glass deposits was located in the mid of the Western Desert of Iraq. It is situated within Rutba Formation (Ceno-manian). Ancient traditional mining method is still used in exploitation the unconsolidated white glass sand from glass sand quarry. The overburden thickness ranges from 2 to 4 m in average. Termite hills were observed around the glass sand quarry extending far from the quarry area. Termites could burrows down and penetrate the sand glass bringing it up to the surface. The depth of penetration reaches more than 35 m. The field observation of the white color of termite hills which are built up by sand glass gave a good indicator for the hidden subsurface deposit and it appears to be a surface signature for finding glass sand directly under the termite hills. The scattered white hills of glass sand on the surface with high content of SiO2, concordant Zr/Hf and Th/U ratios and heavy mineral distribution in both of quarry and termite hills provide a strong evidence of that those termite hills could be an effective tool for exploring subsurface hidden glass sand up to 35 m depth.