No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Biology and ecology of Odontotermes formosanus in China (Isoptera: Termitidae)
Abstract
Odontotermes formosanus, one of the subterranean and fungus-growing termites, is distributed in the southern areas of north latitude 35° in China and Burma, Thailand, Okinawa of Japan, and other Southeast Asian countries. It is by far the most destructive pest to forests, weeds, crops, dams, and dykes. In the last few decades, the biology and ecology of O. formosanus has been studied widely in China. The advances in the study of the biology and ecology of O. formosanus are reviewed in this paper. The contents include mainly the dispersal flight behavior, the establishment and development of nests, the caste differentiation and life history, the temperature and water content of nests and surrounding soil, and the influences of environmental conditions on O. formosanus.
... The black-winged subterranean fungus-growing termite Odontotermes formosanus Shiraki (Termitoidae: Termitidae) is an important decomposer (Bignell and Eggleton 2000), but also a major pest in forestry and agriculture in Southeast Asian countries, including China, Myanmar, Thailand, Vietnam, India, and Japan (Huang et al. 2000, 2006, Cheng et al. 2007). In addition to damaging trees and crops, this species is also known to attack buildings and destroy earthen dams and dykes (Cai et al. 1965, Huang et al. 2008. ...
... Similar to other subterranean dwelling termites, the cryptic lifestyle of Odontotermes has hindered direct observation and the execution of Þeld experiments with appropriate replications. Current knowledge comprises mainly descriptive studies of ßight phenology, colony development, and physical nest structure published in the Chinese literature (reviewed in the article by Cheng et al. 2007). Molecular markers have proven especially useful to overcome these limitations and shed light on many aspects of subterranean termite biology (reviewed in the article by Vargo andHusseneder 2009, 2011). ...
... Whether the comparatively low level of inbreeding is because of the majority of colonies in O. formosanus populations being headed by unrelated pairs of reproductives needs to be tested in future studies of colony breeding systems in O. formosanus, which also will conÞrm whether O. formosanus have just one pair of primary reproductives, as generally assumed (Cheng et al. 2007), or multiple queens, as shown to occur in an African Macrotermitinae (Hacker et al. 2005). ...
The fungus-growing subterranean termite Odontotermes formosanus Shiraki (Isoptera: Termitidae) is a destructive pest in Southeast Asia. To facilitate studies on the biology, ecology, and control of O. formosanus, we isolated and characterized nine novel microsatellite loci from a mixed partial genomic library of O. formosanus and the sympatric Macrotermes barneyi Light enriched for di-, tri-, and tetranucleotide repeats. We screened these loci in three populations of O. formosanus from China. All loci were polymorphic. Three loci showed heterozygote deficit possibly because of the presence of null alleles. The remaining six loci with 4-15 alleles per locus and an average observed heterozygosity of 0.15-0.60 across populations were used for population genetic analysis. Populations from different provinces (Guangdong, Jiangxi, and Hubei) were genetically differentiated, but the genetic distance between populations was surprisingly small (F
ST: 0.03-0.08) and the gene flow was considerable (Nem: 3-8), despite the geographical distance being >300 km. Genetic diversity within populations was low (allelic richness: 5.1-6.3) compared with other subterranean dwelling termites, but consistent with the diversity in species of the family Termitidae. Microsatellite markers developed for O. formosanus will allow further studies to examine the phylogeography, population genetic and colony breeding structure, dispersal ranges, and size of foraging territories in this and closely related species, as well as aid in assessing treatment success.
... The black-winged termite, Odontotermes formosanus Shiraki, is distributed throughout Southeast Asia including Burma, China, India, Japan, Thailand, and Vietnam where it is an economically important pest of crops, forests, and various wooden structures [1]. Although this species consumes wood and other cellulosic material, it does not directly use these for food. ...
... Rather, masticated cellulosic material is used to grow fungus gardens which are the termite food. Termite infestation may result in weakened trees and reduction of yield in fruit trees, or even death of tress, without proper prevention and management [1]. Foraging areas of this species range from 4.2 to 35 m; foraging territories are 13-367.9 ...
... The latter two essential oils have toxic and repellent properties to a number of insects including cockroaches [5,6]. Interestingly, even with its toxic and repellent characteristics, camphor is a preferred indirect food plant of the black-winged termite [1]. ...
Aspects of the biology and ecology of the black-winged termite,
Odontotermes formosanus
Shiraki, were examined in a grove of camphor trees,
Cinnamomum camphora
(L.), located at the Fruit and Tea Institute, Wuhan, China. Of the 90 trees examined, 91.1% had evidence of termite activity in the form of exposed mud tubes on the bark. There was no relationship between tree diameter and mud tube length. Mud tubes faced all cardinal directions; most (60%) trees had multiple tubes at all directions. However, if a tree only had one tube, 22.2% of those tubes faced the south. The majority (>99%) of mud tubes were found on the trunk of the tree. Approximately 35% of all mud tubes had termite activity. Spatial distribution of termite activity was estimated using camphor and fir stakes installed throughout the grove. Camphor stakes were preferred. Kriging revealed a clumped distribution of termite activity.
... All termites live in the stable environment of the nest, where there is a clear social division of labour. The king and queen are responsible for reproduction, soldiers are responsible for protecting the nest, and workers are responsible for collecting food, building the nest, and cultivating combs [13]. Actinomycetes are potential defensive symbionts of fungus-growing termites, because they produce antibiotic substances and are known to play the role of defensive microbes in other insect-fungus symbioses [14]. ...
... In the world of fungus-growing termites, all termites live in the stable environment of the nest, where there is a clear social division of labor. The king and queen are responsible for reproduction, soldiers protect the nest, and workers are responsible for collecting food, building the nest, and cultivating crops (Termitomyces genus) in fungus combs [13]. Hence, the workers and soldiers, which have a wide range of activities in the soil, are more vulnerable to pathogens. ...
Background
Actinomycetes are important microbes, and they are very important for developing active substances for useful drugs. Actinomycetes are numerous inhabitants, and they are widely distributed in the nest of fungus-growing termites. Previously, we isolated and purified numerous actinomycetes from the combs of Odontotermes formosanus and obtained a variety of valuable natural products.
Results
Here, we isolated and purified actinomycetes from fungus-growing termite Odontotermes formosanus using medium-based cultures. Among the eight media tested, M7 and I-HV media were found suitable for isolating actinomycetes . Further, 84 actinomycetes, including 79 Streptomyces isolates, were isolated and purified from O . formosanus and its combs, which belong to four genera ( Streptomyces , Kribbella , Amycolatopsis, and Cellulosimicrobium ). Then , the type and quantity of actinomycetes were positively correlated with the activity range of termites. Twenty-two actinomycetes strains showed antimicrobial activities. Among them, the BYF18, BYF48, BYF70, and BYF106 strains exhibited antifungal activities against five pathogenic fungi, with zone of inhibition (ZOI) values ranging from 3 to 21 mm. Grincamycin N was isolated and purified from the metabolites of Streptomyces lannensis (BYF106), and it displayed antibacterial activities against Staphylococcus aureus (ZOI = 13.82 ± 0.52 mm) and Micrococcus tetragenus (ZOI = 17.6 ± 0.5 mm) (gentamycin sulfate, as the positive control, had ZOI values of 19.9 ± 0.5 mm and 30.83 ± 0.75 mm, against S. aureus and M . tetragenus , respectively).
Conclusions
Our results confirmed that the actinomycetes associated with O. formosanus are important sources of new active substances.
... O. formosanus(Black-winged Termites) were distributed throughout the UMYUK campus, although they were found to be more at the Student Centre than the other locations. This species has been described as an economically important pest of crops, forests and various wooden structures by Cheng et al. (2007). The authors added that this termite species consumes wood and other cellulosic material, even though it does not directly use these for food. ...
... Rather, masticated cellulosic material is used to grow fungus gardens which are the termite food. Presence of O. formosanusand its infestation in the permanent campus of UMYUK may result in weakened trees and reduction of yield in fruit trees, or even death of trees if not properly managed and prevented as suggested by Cheng et al. (2007). ...
... O. formosanus (Black-winged Termites) were distributed throughout the UMYUK campus, although they were found to be more at the Student Centre than the other locations. This species has been described as an economically important pest of crops, forests and various wooden structures by Cheng et al. (2007). The authors added that this termite species consumes wood and other cellulosic material, even though it does not directly use these for food. ...
... Presence of O. formosanus and its infestation in the permanent campus of UMYUK may result in weakened trees and reduction of yield in fruit trees, or even death of trees if not properly managed and prevented as suggested by Cheng et al. (2007). ...
Studies on the abundance of termitaria at the permanent campus of Umaru Musa Yar’adua University, Katsina (UMYUK) were conducted between April and June, 2013 to find out the occurrence of termites and termitaria in the study area. Three plots of 100m2 of each of the eight locations namely: Auditorium, Central Mosque, Centre for Renewable Energy Research, Female Hostel, Geographical Garden, Library, Students Centre and UMYU Store. Samples of the termite species were taken and identified as Odontotermes formosanus Shiraki dominating all the termitaria. Female Hostel and Student Centre had the highest (5) number of live termitaria while the least (1) was found in UMYU Store and Auditorium respectively. The highest (173.00 cm) basal circumference of live termitaria was found around the Auditorium, while the lowest (45.20 cm) was found around the area of Centre for Renewable Energy Research. Auditorium had the highest (38.00 cm) live termitaria, while Centre for Renewable Energy Research had the lowest (21.60 cm) live termitaria. The height of the dead termitaria was lower (18.00 cm to 33.50 cm) than that of the live ones. Irregular shapes of termitaria occurred in almost every location followed by dome and pyramidal shape, while conical shape was the least in occurrence. Presence of termite species as well as their termitaria suggests that as the termites aerate the soil, they bring about decomposition, and hence play important role in soil amendments and addition of fertility to the soil.
Key words: Abundance, Katsina, Odontotermes formosanus, Termitaria
... However, in our study, the optimal temperature of the laccase was 10 • C and the laccase activity was stable between 0 • C and 30 • C, but the activity was completely lost when the temperature was above 50 • C. The temperature optimum was lower than those of the other laccases. This may be due to the lower temperature in nest of O. formosanus which is kept at 11-28 • C throughout the year [31]. ...
... Sadhasivam et al. found that the inhibition of laccase activity from Trichoderma harzianum was 1.5% for Fe 3+ , 3.3% for K + , 7.6% for Zn 2+ , 1.4% for Mg 2+ , 0.8% for Mn 2+ , 0.0% for Na + , 0.0% for Ba 2+ , and 0.6% for Ca 2+ at 1 mM concentration [14]. In another study, the inhibition of the activity of the purified laccase from the edible mushroom Lentinula edodes was 99% for Sn 2+ , 70% for Ca 2+ , 64% for Zn 2+ , 55% for Hg 2+, 54% for K + , and 45% for Cd 2+ in the presence of 1 mM metal ions [31]. However, all metal ions tested exhibited partial inhibition on the laccase activity in this study and the inhibition percentages were between 15% and 35% except Fe 2+ which inhibited 89% of the enzyme activity at 1 mM concentration. ...
A new enzyme was isolated from the fungus combs in the nest of Odontotermes formosanus and identified as a laccase. The single laccase was purified with a purification factor of 16.83 by ammonium sulphate precipitation and anion exchange chromatography, to a specific activity of 211.11 U mg−1. Its molecular mass was 65 kDa. The optimum pH value and temperature were 4.0 °C and 10 °C with ABTS as the substrate, respectively. The enzyme activity stabilized at temperatures between 10 °C and 30 °C and decreased rapidly when the temperature was above 30 °C. The Vmax and Km values were 3.62 μmol min−1 mg−1 and 119.52 μM, respectively. Ethanol concentration affected laccase activity, inhibiting 60% of enzyme activity at a concentration of 70%. Metal ions of Mg2+, Ba2+ and Fe2+ showed inhibition on enzyme activity of 17.2%, 5.3% and 9.4%, respectively, with the increase of metal ions concentration from 1 mM to 5 mM. Especially Fe2+ strongly inhibited enzyme activity up to 89% inhibition at a concentration of 1 mM.
... Insects Odontotermes formosanus belongs to the most advanced termite subfamily, Macrotermitinae, the fungusgrowing termites; it occurs in Southeast Asia, mainly South China (Huang et al., 2000;Zhong and Liu, 2002;Cheng et al., 2007). Odontotermes formosanus builds large subterranean nests with cavities linked by a network of galleries. ...
... Values were analyzed by χ 2 test Values indicated by asterisk were not from detection, but were estimated from SPME ratio analyses of the tested females after headspace-SPME (Z)-dodec-3-en-1-ol, in addition to its the orientation effect, may play a role in species-specific attraction for sympatric species from Southeast Asia. Odontotermes formosanus is sympatric in this area with other Macrotermitinae species (Huang et al., 2000;Zhong and Liu, 2002;Cheng et al., 2007). Among them, An. pakistanicus secretes a sex-pairing pheromone comprised of (Z,Z)-dodeca-3,6-dien-1-ol only . ...
The sex-pairing pheromone of the black winged subterranean termite, Odontotermes formosanus (Shiraki) (Isoptera, Termitidae), was investigated using headspace-SPME, GC-MS, GC-EAD, and attraction bioassays. Females secrete the pheromone from their sternal gland to attract males. The sex-pairing pheromone is composed of (Z,Z)-dodeca-3,6-dien-1-ol and (Z)-dodec-3-en-1-ol, estimated at 9 to 16.64 ng and 0.2 to 0.54 ng, respectively. Both short- and long-distance sex attraction bioassays were employed to show that these compounds act in synergy at long distance, but only (Z,Z)-dodeca-3,6-dien-1-ol is active at short distance. The pheromone may be useful in efforts to control this pest, which is considered one of the most harmful termite species in Southeast Asia.
... Subterranean termites that build nests in the soil matrices of earth embankments adversely affect the stability of these structures in paddy farming regions of southern China (Li et al. 1986(Li et al. , 2001Wang et al. 2007) by increasing the hydraulic conductivity and water infiltration of the filling soil of embankment (Lee and Foster 1991;Leonard and Rajot 2001;Ackerman et al. 2007;Ahmed and Pradhan 2018;Cheik et al. 2019). Odontotermes formosanus Shiraki are widely distributed in the southern area of the Yellow River in China (Mo et al. 2004;Hu et al. 2006;Tian et al. 2009), posing a serious threat to crops, forests, and various wooden structures (Zhong and Liu 2002;Cheng et al. 2007; Kuswanto et al. 2015) as well as the earth 1 3 embankments along the rivers and reservoirs (Li et al. 1994;Hu et al. 2007;Henderson 2008;Huang et al. 2012). When constructing their nests, they dig long, curved tunnels and large internal cavities that can adversely affect the stability and subsequent safety of earth embankments (Tian et al. 2008;Yang et al. 2009;Ghaly and Edwards 2011;Umaru et al. 2014). ...
Subterranean termites (Odontotermes formosanus Shiraki) that build nests in the soil matrices of earth embankments may adversely affect the stability of these structures in paddy farming regions of southern China. An adult termite nest comprises a primary chamber, fungus gardens, passageways, and other shelter tubes. These porous architectures enable high hydraulic conductivity and rapid groundwater flow. In this study, we performed a field survey to characterize these termite nest architectures and proposed a simulation method that estimates seepage and associated stability in termite-infested earth embankments. Three types of nest architectures—straight, siphon, and string—were investigated in situ. Groundwater flow and its relationship with earth embankment stability were analyzed using a numerical model based on the two-dimensional Richards equation in the HYDRUS software package. Results indicated that the presence of termite nests affected seepage zone geometry and substantially affected its phreatic line, seepage flux, and global and local stabilities of the earth embankment. In the cases examined here, the presence of termite nests resulted in a maximum factor of safety reduction of 17% along the downstream slope. The local instability zones of earth embankment, resulting from clogged termite nest passageways along the downstream slope, were also assessed.
... The black-winged termite, Odontotermes formosanus (Shiraki), is a severe forestry pest distributed in China and Southeast Asia. This species is known to build subterranean nests and construct extensive mud tubes and/or shelters on tree trunks, which favor the consumption of bark and wood (Cheng et al., 2007;Appel et al., 2012). Our preliminary observations showed a long-lasting and massive termite exodus from the tree crown to underground tunnels as well as repairing behaviors when the mud tube was damaged. ...
The escaping behavior of termites has been documented under laboratory conditions; however, no study has been conducted in a field setting due to the difficulty of observing natural behaviors inside wood or structures (e.g., nests, tunnels, etc.). The black-winged termite, Odontotermes formosanus (Shiraki), is a subterranean macrotermitine species which builds extensive mud tubes on tree trunks. In the present study, 41 videos (totaling ∼2,700 min) were taken on 22 colonies/subcolonies of O. formosanus after their mud tubes were partially damaged by hand. In general, termites consistently demonstrated three phases of escape, including initiation (wandering near the mud-tube breach), individual escaping (single termites moving downward), and massive, unidirectional escaping flows (groups of termites moving downward). Downward moving and repairing were the dominant behavioral activities of individuals and were significantly more frequent than upward moving, turning/backward moving, or wandering. Interestingly, termites in escaping flows moved significantly faster than escaping individuals. Repairing behavior was observed shortly after the disturbance, and new mud tubes were preferentially constructed from the bottom up. When predators (i.e., ants) were present, however, termites stopped moving and quickly sealed the mud-tube openings by capping the broken ends. Our study provides an interesting example that documents an animal (besides humans) simultaneously carrying out pathway repairs and emergency evacuation without congestion.
... O. formosanus builds a large nest comprising large cavities and small chambers linked by a network of galleries. The foraging distance of a colony has been recorded as covering 4 to 35 m [41,42]. The termites build a circular gallery around the food to facilitate the activity of foragers [43]. ...
The eusocial termites are well accomplished in chemical communication, but how they achieve the communication using trace amount of no more than two pheromone components is mostly unknown. In this study, the foraging process and trail pheromones of the fungus-growing termite Odontotermes formosanus (Shiraki) were systematically studied and monitored in real-time using a combination of techniques, including video analysis, solid-phase microextraction, gas chromatography
coupled with either mass spectrometry or an electroantennographic detector, and bioassays. The trail pheromone components in foraging workers were (3Z)-dodec-3-en-1-ol and (3Z,6Z)-dodeca-3,6-dien-1-ol secreted by their sternal glands. Interestingly, ratio of the two components changed according to the behaviors that the termites were displaying. This situation only occurs in termites whereas ratios of pheromone components are fixed and species-specific for other insect cuticular glands. Moreover, in bioassays, the active thresholds of the two components ranged from 1 fg/cm to 10 pg/cm according to the behavioral contexts or the pheromonal exposure of tested workers. The two components did not act in
synergy. (3Z)-Dodec-3-en-1-ol induced orientation behavior of termites that explore their environment, whereas (3Z,6Z)-
dodeca-3,6-dien-1-ol had both an orientation effect and a recruitment effect when food was discovered. The trail pheromone of O. formosanus was regulated both quantitatively by the increasing number of workers involved in the early phases of foraging process, and qualitatively by the change in ratio of the two pheromone components on sternal glandular
cuticle in the food-collecting workers. In bioassays, the responses of workers to the pheromone were also affected by the
variation in pheromone concentration and component ratio in the microenvironment. Thus, this termite could exchange more information with nestmates using the traces of the two trail pheromone components that can be easily regulated within a limited microenvironment formed by the tunnels or chambers.
... Furthermore, this species can build large subterranean cavities inside earthen dikes and dams, thereby damaging piping, which can result in the collapse of the dikes and dams [9]. To date, the patterns of caste differentiation and intercolonial aggression in O. formosanus have been studied101112, but there are no research reports about molecular basis underlying its caste differentiation and aggression. Despite its significant importance of biology and economics, genomic sequence resources available for O. formosanus are very scarce. ...
The subterranean termite Odontotermes formosanus (Shiraki) is a serious insect pest of trees and dams in China. To date, very little is known about genomic or transcriptomic data for caste differentiation and aggression in O. formosanus. Hence, studies on transcriptome and gene expression profiling are helpful to better understand molecular basis underlying caste differentiation and aggressive behavior in O. formosanus.
Using the Illumina sequencing, we obtained more than 57 million sequencing reads derived from the heads of O. formosanus. These reads were assembled into 116,885 unique sequences (mean size = 536 bp). Of the unigenes, 30,646 (26.22%) had significant similarity with proteins in the NCBI nonredundant protein database and Swiss-Prot database (E-value<10(-5)). Of these annotated unigenes, 10,409 and 9,009 unigenes were assigned to gene ontology categories and clusters of orthologous groups, respectively. In total, 19,611 (25.52%) unigenes were mapped onto 242 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG). A total of 11,661 simple sequence repeats (SSRs) were predicted from the current transcriptome database. Moreover, we detected seven putative genes involved in caste differentiation and six putative genes involved in aggression. The qPCR analysis showed that there were significant differences in the expression levels of the three putative genes hexamerin 2, β-glycosidase and bicaudal D involved in caste differentiation and one putative gene Cyp6a20 involved in aggression among workers, soldiers and larvae of O. formosanus.
To our knowledge, this is the first study to characterize the complete head transcriptome of a higher fungus-cultivating termite using high-throughput sequencing. Our study has provided the comprehensive sequence resources available for elucidating molecular basis underlying caste differentiation and aggressive behavior in O. formosanus.
... Odontotermes formosanus (Shiraki) (Isoptera: Termitidae), in the Þeld; this termite species was chosen because it has a wide distribution in Asia and is known to feed on many plant species (Cheng et al. 2007). Currently, the primary control measure against O. formosanus in China is bait technology. ...
Odontotermes formosanus (Shiraki) (Isoptera: Termitidae) is one of the most destructive plant pests in China, which control relies mainly on baits strategies. Baits made from the wood of eight different tree species were used to study the feeding preference of this termite, and conversely wood protection strategies of the tree species. Three bait types were used to identify wood protection strategies: solid wood (physical and chemical protection), crude flour (chemical protection) made from ground wood, and extracted flour (no protection) made by extracting crude flour with ethanol and toluene. Feeding preference was influenced by wood species and bait type. For solid wood, Magnolia denudata Desr (75%) and Elaeocarpus glabripetalus Merr (41%) were most preferred; for crude flour, E. glabripetalus (97%) and Quercus variabilis Blume (92%) were most preferred; and for extracted flour, there were no significant differences between wood species, demonstrating the influence of chemical defense. The greatest contrast between bait types was for Platanus orientalis L, the least preferred as solid wood and crude flour, suggesting that chemical defense compounds are particularly important in this species. Solid wood consumption was inversely correlated with wood density. Extracted flour consumption was positively correlated with glucose concentration. There was no direct effect of holocellulose and other components tested. O. formosanus preferred to fed on soft wood with low chemical protection (M. denudata); conversely trees protected their wood either physically [e.g., E. glabripetalus, Q. variabilis, Cinnamomum camphora (L.) Presl, and Ligustrum lucidum Aiton] or chemically (Populus bonati Levl) or a combination of both strategies (Liquidamba formosana Hance and P. orientalis).
Fungus‐growing termites (subfamily Macrotermitinae) cultivate the symbiotic basidiomycete fungus Termitomyces in their fungus comb to digest cellulosic materials and to supply nitrogen‐rich fungal diet. In Japan, the fungus‐growing termite Odontotermes formosanus is found on the Yaeyama Islands and Okinawa Island, Okinawa Prefecture. Odontotermes formosanus is thought to have been recently and artificially introduced to Okinawa Island as its distribution is discontinuous and restricted to small areas. Previous DNA analyses revealed that two types of Termitomyces, namely Termitomyces sp. Type A and Termitomyces sp. Type B, whose fruiting bodies correspond to Termitomyces microcarpus‐like pseudorhiza‐lacking small mushroom and Termitomyces intermedius, respectively, are cultivated by O. formosanus on the Yaeyama Islands. However, information about the Termitomyces types cultivated by O. formosanus on Okinawa Island is limited. To define the fungal types cultivated by O. formosanus on Okinawa Island, I developed a diagnostic polymerase chain reaction method using primer sets specific to the nuclear ribosomal DNA sequences consisting of the internal transcribed spacers (ITS1 and ITS2) and 5.8S rDNA of Termitomyces not using fungal mycelium, but using the termite gut metagenome including fungal DNA as a template. The results indicated that the same two Termitomyces types from Iriomote Island are cultivated by O. formosanus on Okinawa Island. The distribution pattern of Termitomyces types on Okinawa Island showed that Termitomyces sp. Type A is limited to the mountainous side of Sueyoshi Park, despite Termitomyces sp. Type B being widely distributed in the area in which O. formosanus is found. This finding implies that O. formosanus on Okinawa Island was recently introduced from Iriomote Island to Sueyoshi Park.
Subterranean termites are a group of important pests that damage buildings and other structures in urban and rural areas. To reduce the infestation of termites, monitor-controlling system/devices have been used for termite control since 2006 in some provinces of China. However, heavy labor input was needed during the daily checks and maintenance of monitor-controlling systems/devices. An automatic alarm detector for monitor devices was evaluated in this study. The automatic alarm detector consists of alarm equipment, an electric wire, binding post, conducting strip, graphite powder pole, and wood preferred by termites. This permits early and automatic detection of the presence of the termites in the proximity of the non-infected or more infected parts of the building. With the use of monitor devices with detectors to protect buildings and other structures from termite infestation, the cost of daily maintenance could be reduced greatly. We used a number of these devices for monitoring the infestation of Reticulitermes flaviceps (Oshima) in soil around buildings in this study. Among 54 sets of monitor devices tested in the field, 23 sets of devices gave out an alarm signal within 60 days of installation, with 22 having active termite infestations.
The Objectives of this research were to compare the ability of fenvalerate, ivermectin and fipronil to control the damage of Odontotermes formosanus Shiraki and Macrotermes barneyi Light to trees in Huagaishan Park and Cuiweishan Park, Wenzhou city, Zhejiang province, China during the period of August 2008 to October 2009. The results of irrigating liquid chemicals in the soil around the base of trunks indicated that 0.05%-0.4% fenvalerate solutions and 0.003125%-0.025% fipronil solutions effectively retarded termite attacks on trees. However, 0.0025%-0.02% ivermectin solutions could only repress infestation by O. formosanus and M. barneyi for a shorter amount of time. This information shows fenvalerate and fipronil are preferable to ivermectin for the control of O. formosanus and M. barneyi.
Odontotermes formosanus and Macrotermes barneyi are two important insect pests in seedling nurseries in the south of China. They build mud tubes and mud covers on the surface of seedlings and feed on the bark of seedlings. The growth of seedlings is consequently impacted by these infestations and some seedlings die. In this paper, two formulations of ivermectin (0.01% bait and 3% dust) for the control O. formosanus and M. barneyi in Cinnamomun camphora (L) Presl. forest were evaluated in the Lanxi City Seedling Nursery, Zhejiang Province, China during the period of August, 2009 to October, 2010. The results indicated that the percent of trees damaged by termites was more than 85.5% in the control area during the period of test, and the corresponding percent was 1.00% in the dust application area and 0.22% in the bait application area. These data show ivermectin is a potential alternative to mirex and could be formulated into bait or dust for the control of O. formosanus and M. barneyi in seedling nursery.
Higher termites feed primarily on wood and wood-related materials. The degradation of cellulose in food by termites depends on cellulase, which is secreted by the termite itself and/or its symbionts. This study investigated the synergistic activities of the symbiotic fungus Termitomyces albuminosus on the cellulase of a higher termite, Odontotermes formosanus. We initially used salicin or carboxymethylcellulose as a substrate and no substrate as a control, then mixed these enzyme extracts of each caste of O. formosanus with its symbiotic fungus T. albuminosus. The amount of sugar degraded was measured by the Somogyi-Nelson methods. The results indicated that the mixture of enzyme extracts between the workers or the soldiers and the symbiotic fungus showed significantly higher reducing sugar content compared with the enzyme extracts of the workers, the soldiers or the symbiotic fungus (p>0.05). These data could provide new proofs for explaining the relationship between higher termites and their symbiotic fungus.
Odontotermes formosanus (Shiraki) is a fungus-growing higher termite. The symbiotic fungus Termitomyces albuminosus plays an important role in the degradation of lignocellulose ingested by the termites. The activities of cellulase in O. formosanus and its symbiotic fungus T. albuminosus were compared in this study. The results indicated that the worker termites, the soldier termites and the symbiotic fungus showed different levels of cellulase activity. The workers had the highest activities of endo-β-1, 4-Glucanase and β-Glucosidase, and there was no significant difference in the activities of endo-β-1, 4-Glucanase and β-Glucosidase between the symbiotic fungus and the soldier termites. The results provide new information for explaining the role of T. albuminosus in the food digestion of O. formosanus.
Seasonal foraging activity of termites depends principally on air temperatures which are increasing in recent years due to global warming. To examine the seasonal foraging activity of termites, a walking belt transects of 1 m wide was randomly laid every two weeks in four plots. Inside the frame of each plot, 100 wood logs were examined for the presence or absence of termites during one year. To determine the effect of temperature on termite foraging activity, the relation between the monthly mean temperatures (maximum and minimum) and the termite foraging activity were analyzed. The effect of climate change on this activity was analyzed by comparing our results with a previous study. In our study period, termites foraged throughout all the year. Their activities were low (but occurred) in winter. Foraging increased significantly in summer, reaching a maximum in autumn (especially for Odontoterms formosanus). Odontotermes species were the most active termites in our study sites. The species of this genus attacked 23% of the examined wood logs. Odontotermes dimorphus was also recorded for the first time in Hangzhou. The foraging activity of termites was positively correlated with air temperature. The occurrence of termite activity in winter and the presence of O. dimorphus in our study sites could be a result of global warming. We suggest that any management strategy against termites in these sites should be carried out at the period of high foraging activity.
Fungus-growing termites play important roles in biorecycling of lignin through their symbiotic fungi of the genus Tennitomyces. In this study, we examined a series of ligninases, including laccase, lignin peroxidase and manganese peroxidase in materials from a colony of Odontotermes formosanus. Only laccase activity was detected in the symbiotic fungus, fungus comb and alimentary tract of workers of O. formosanus. The laccase activities in descending order were as follows: symbiotic fungus > fungus comb > worker alimentary tracts. The activity of laccase was strongly inhibited by DTT, sodium fluoride and L-cysteine. Crude laccase from the symbiotic fungus exhibited high activity at a low pH value and high temperature. The results suggest that the symbiotic Termitomyces fungus takes part in lignin degradation of plant litter through secreting laccase in fungus combs in colonies of O. formosanus.
Tropical termites are physiologically adapted to a narrow range of climatic conditions, and as a result may be particularly impacted by global climate change. Because of their key roles as decomposers and ecosystem engineers, any climatic impact on termites could have serious ramifications for tropical ecosystems. The ability of termites to mediate their nest environment could allow them to cope with these changes.The temperature and RH in nests of the tropical termite Nasutitermes acajutlae were compared with ambient conditions on the island of St John, U.S. Virgin Islands, over a 5-year period using data loggers inserted into nest cartons.Nest conditions were found to be significantly warmer, more humid, and less variable than ambient conditions with respect to both temperature and RH.A comparison of dead nests, live non-reproductive nests, and live reproductive nests revealed that temperature mediation appears to be primarily the result of the presence of termites, with reproductive nests producing the highest temperatures, while high RH is maintained by the insulating effects of the nest material.Environmental variability across the years of this study had a significant influence on nest temperature and RH, suggesting that if tropical conditions become warmer and drier as predicted, N. acajutlae may have difficulty adapting over the long term.
Present studies on swarming of termites of Mianwali indicated that no
single factor alone was responsible for the initiation of swarming of termites.
Instead, a combination of various environmental factors was responsible for
swarming and rainfall played a critical role in creating a suitable humidity and
temperature combination for flight period. During the period, 83 swarms of
eight species of termite were observed. The influence of extrinsic factors on
the daily capture rates was analyzed by correlation coefficient and regression.
Atmospheric temperature and wind speed turned out to be the main determinants,
as humidity remained more or less in the same range and swarming
mostly continued in the absence of rainfall.
We study the effect of symmetry on volume conserving models without deposition and evaporation. By using the master equation approach, we identify two types of stochastic continuum equation with a conservative noise, depending on the symmetry of hopping rate in diffusion rules. In the model with symmetric hopping rate, a Laplacian term is essentially absent from the continuum equation. The dynamic scaling of this model is thus determined by the nonlinear fourth order equation with a conservative noise. When the symmetry is broken, a Laplacian term may be present, so the asymptotic scaling behavior is governed by the Laplacian term with nonzero coefficient. We verify this result by investigating a simple discrete model analytically.
Odontotermes formosanus is the most serious termite pest species of dams and dikes in Southern China. The dispersal distances of the alates are im-portant to better understand its impact and to determine the effectiveness of control tactics. A mark-recapture study using fluorescent spray paints was conducted to characterize dispersal distances of an O. formosanus colony which was located in the Longdong reservoir dam, Guangzhou, China. O. formosanus alates were capable of flying 120 to at least 743 m in the direction of the low prevailing wind. These results could help to formulate a manage-ment strategy against O. formosanus. The advantages of the fluorescent spray paint / fluorescence microscopy technique is also discussed.