首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The termite assemblages of the Krakatau islands and five sites in Sumatra and Java were investigated, using a standardized transect sampling method. Five species were found on the Krakatau islands that have not been collected there before. The total number of termites recorded on the islands since the 1883 volcanic eruption is now twelve species, all of which are wood feeders. No termites nesting in or feeding on the soil were found on the Krakataus, suggesting that rafting in wood is the primary method by which the termites recolonized the islands.  相似文献   

2.
Savannah are ecosystems in which mineral nitrogen is considered as a limiting factor for plant productivity. They are heterogeneous and spatially structured in patches, or islands, where mineral nitrogen content is concentrated. Among the soil macrofauna, termites of the Macrotermitinae subfamily are major determinants of soil heterogeneity through the biogenic underground nest structures (fungus‐comb chambers) they produce. To study the role of the heterogeneity created by termites on Pennisetum pedicellatum, an herbaceous grass species was grown in greenhouse. This was carried out using an homogeneous soil poor in mineral nitrogen, and an heterogeneous soil with patch, made of (i) Ancistrotermes cavithorax fungus‐comb chamber wall and (ii) soil with the same mineral nitrogen content as the termite handled soil. Plants exhibited a better growth on patch of termite‐modified soil whereas no significant differences were shown with the supply of mineral nitrogen. The presence of fungus‐comb chamber wall material resulted in an increase of fine root biomass and root/shoot ratio. We conclude that termites, through their building activities, may create nutrient patches available to grasses. Concurrently, our data illustrate that the higher mineral nitrogen content in termite‐built structures is not the only factor responsible for plant growth.  相似文献   

3.
More than 100000 blood pythons (brongersmai) and short-tailed pythons (curtus and breitensteini) are taken from Borneo and Sumatra each year for the commercial leather trade. Traditionally, all have been treated as a single polytypic species (Python curtus) , with three subspecies differing in colour, size and geographic distribution. Analyses of DNA sequences and morphological data clarify the phylogenetic relationships, taxonomy and biogeography of this group. The lineage is monophyletic, and each of the three subspecies differs from the other two both morphologically and genetically. Given the morphological and genetic distinctiveness of each taxon, we here elevate the three subspecies to full species status. Python brongersmai is the most distinctive in terms of colour (of the three, only brongersmai has colour-morphs that are red or orange), size (it grows to 2.6 m, vs. approx. 2.0 m for the other taxa), and scalation (e.g. brongersmai has <166 ventral scales, vs. <166 in the other taxa and has two supralabials over each orbit, vs. one supralabial for the other two taxa). In terms of cytochrome b mitochondrial DNA sequence data, brongersmai is almost as distant genetically from the short-tailed pythons (8.9% divergence) as is the reticulated python (P. reticulatus: 10.3% divergence). The other two taxa (P. breitensteini from Kalimantan and P. curtus from western and southern Sumatra) are closely related (3% divergence), despite their disjunct distribution (separated by P. brongersmai). Sea-level fluctuations provide a plausible biogeographic scenario to explain phylogenetic divergence within this lineage. Given the distinctiveness of the component taxa, and the ease with which even dried skins can be identified to species level (based on ventral counts), the managers of this important commercial resource should no longer treat the P. curtus group as a single biological taxon.  相似文献   

4.
Three Crematogaster ant species, C. (Orthocrema) javanica Menozzi, C. (O.) myops Forel and C. (O.) masukoi sp. nov., share reduced compound eyes which characterizes them among Asian species of the subgenus Orthocrema. The new species is described based on material from Borneo. It can be distinguished from C. javanica and C. myops by its smooth surface of clypeus and acutely produced subpetiolar process. Reduced compound eyes and yellowish body suggest that these three species are subterranean.  相似文献   

5.
Summary. Termite workers from all families examined had no arolia (=adhesive pads) on their tarsi and are unable to climb smooth vertical surfaces such as glass or polypropylene plastic. This contrasts with ants where both workers and alates of most species possess arolia and are able to climb these surfaces. Arolia were present in alates of the majority of species investigated from three of the four most basal termite families (Mastotermitidae, Termopsidae and Kalotermitidae), though absent from the basal family Hodotermitidae that contains only three genera. Alates in the two kalotermitid species tested readily climbed glass walls. The complete evolutionary loss of arolia from alates in the specious two most apical termite families (Rhinotermitidae and Termitidae) suggests paedomorphosis. Very smooth surfaces probably cannot be used to completely prevent entry of rhinotermitid termites into buildings because these termites can eventually build galleries of feces and soil over these surfaces. However, an experiment with Coptotermes formosanus showed that a smoother surface significantly slows down the rate of gallery building.Received 12 February 2004; revised 17 June 2004; accepted 29 June 2004.  相似文献   

6.
According to previous phylogeographic studies, high mountains at low latitudes are important areas for the study of the evolutionary history of arctic–alpine plants in surviving the Pleistocene climatic oscillations. To evaluate this hypothesis, we elucidated the genetic structure of the arctic–alpine plant, Loiseleuria procumbens , in the Japanese archipelago, which corresponds to one of the southernmost limits of its distribution, using 152 individuals from 17 populations that covered the entire distribution of the Japanese archipelago and Sakhalin, in addition to samples from Sweden. Based on 854 bp of chloroplast DNA, we detected eight haplotypes. Along with haplotype distribution, strong genetic differentiation between populations in central and northern Japan was elucidated by a neighbour-joining tree (100%) and spatial analysis of molecular variance (79%), which is consistent with other alpine plants in Japan, regardless of the species' range. In addition, the southernmost populations from northern Japan showed specific genetic structure, although the remaining areas of northern Japan and Sakhalin harboured an homogenous genetic structure. Our results suggest that the populations in central Japan persisted for a long time during the Pleistocene climatic oscillation and that genetic divergence occurred in situ , supporting our hypothesis in conjunction with a previous study of another arctic–alpine plant, Diapensia lapponica subsp. obovata .  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 403–412.  相似文献   

7.
The essential oil of catnip, Nepeta cataria (Lamiacae) was evaluated for behavioral effects on two populations of subterranean termite, Reticulitermes flavipes (Kollar) and R. virginicus (Banks) (Isoptera: Rhinotermitidae). The catnip essential oil contained approximately 36:64 E,Z-nepetalactone and Z,E-nepetalactone, respectively. The time to 50% dissipation (DT50) of the isomers in sand was dependent on dose, and ranged from 5.7 to 12.6 d for the E,Z-isomer and 7.7-18.6 d for the Z,E-isomer. For R. flavipes, the 24-h topical LD50 value was approximately 8200 microg/g termite. The 24-h fumigation LC50 value for R. flavipes was between 36 and 73 microg/ml air, and the 7-d fumigation LC50 value was between 14 and 36 microg/ml air. Exposure of R. virginicus to treated sand resulted in a 24-h LC50 value (95% F.L.) of 84 (67.6, 112) microg/cm2 and a 7-d LC50 value of 21.1 (16.4, 26.8) microg/cm2; for R. flavipes these values were 63.2 (53.7, 73.9) and 44.4 (34.6, 58.1) microg/cm2, respectively. Vertical tunneling through treated sand was eliminated at 500 ppm for R. virginicus and at 250 ppm for R. flavipes. Horizontal tunneling was stopped at 250 ppm for R. virginicus and reduced at doses above 250 ppm for R. flavipes. Although tunneling ceased in these tests, mortality was not high, indicating that the termites avoided the treated sand. Efficacy of catnip oil was equivalent to other monoterpenoids reported in the literature.  相似文献   

8.
Abstract Two years after an intense fire burnt large parts of the Barrens in Mediterranean Western Australia, its effects on wood-eating and litter-harvesting termites were investigated. Nine vegetation types varying in height, structure and floristics, were used for paired unburnt/burnt comparisons. Wood-eating termites were significantly less abundant and diverse in burnt stands, apparently by perishing in the fire rather than through food limitation. The harvester Tumulitermes westraliensis was not significantly affected by fire. Strategies enhancing persistence despite intense fire were construction of hard, protective clay mounds (Coptotermes frenchi, Amitermes obeuntis, T. westraliensis) and flexibility to site nests in diverse microhabitats, including the mounds of other termite species (Heterotermes).  相似文献   

9.
In coconut plantations of northern New Guinea, the arboreal nesting termite community comprises three species:Nasutitermes princeps, N. novarumhebridarum, andMicrocerotermes biroi. In orde to assess the importance of intraspecific interactions in this community, we conducted pairwise encounters between batches of individuals in the laboratory and between entire nest populations in seminantural conditions. Three levels of agonism were defined in laboratory bioassays: anagonism, moderate agonism, and strong agonism. Anagonism was observed during all control tests with homocolonical groups and in some tests with allocolonial groups of all species. Moderate agonism included initial aggressiveness that subsequently faded out, and initially passive encounters where aggression progressively built up and led to fighting. Strong agonism corresponded to initial aggressiveness and fighting. Results obtained in alboratory bioassays were consistent with bioassays in seminatural conditions. WhenNasutitermes colonies were anagonists in laboratory bioassays, their foraging trails merged without aggression in field tests.N. princeps nests that were moderately agonistic in laboratory tests fought and either continued to avoid each other or finally joined after elimination of the most aggressive individuals. The most aggressiveM. biroi andN. princeps colonies fought and their foraging trails diverged afterward. Direct attacks on alien nests were winnessed inM. biroi. In all species, anagonism occurred in 21–34% of the combinations tested, between either geographically close or distantcolonies. An exeption was a group of 112 anagonist nests ofN. princeps, which most probably constituted a supercolony. The level of agonism betweenNasutitermes colonies was constant during the wet and dry season. Termite colonies excluded each other, both intra- and interspecifically, from the coconut trees, and their territories seem distributed in a mosaic pattern. Agonism between colonies may result in the elimination of the weakest colonies or in trail divergence, maintaining this mosaic. In cotrast, lack of agonism between some colonies suggests the possibility of colony fusion and gene exchanges without nuptial flights.  相似文献   

10.
1. Carbon (δ13C) and nitrogen (δ15N) stable isotope ratios of termites (Isoptera) were examined in Darwin, northern Australia. It is suggested that the stable isotope technique, together with phylogenetics, is a useful tool to understand the evolution of functional groups in detritivores.
2. A high δ15N value was observed in the Termes-Capritermes branch of the subfamily Termitinae and the genus Amitermes , two distinct taxonomic groups that evolved from wood-feeding to soil-feeding in Australia. Among eight Termes-Capritermes branch species, only two species ( Xylochomitermes melvillensis and Ephelotermes melachoma ) were discernible as wood/soil interface feeders, the remaining six species analysed were soil-feeders, where the diet preference was identified by using δ15N of workers.
3. The Termes-Capritermes group in Australia contains both wood/soil interface feeders and soil-feeders, whereas wood/soil interface feeders in Cameroon are from the Termes-Capritermes branch while soil-feeders are from Cubitermes group. The result confirmed that soil-feeding forms evolved both in Australia and Africa, but from different phylogenetic groups.  相似文献   

11.
Fungus-growing termites cultivate their mutualistic basidiomycete Termitomyces species on a substrate called a fungal comb. Here, the Suicide Polymerase Endonuclease Restriction (SuPER) method was adapted for the first time to a fungal study to determine the entire fungal community of fungal combs and to test whether fungi other than the symbiotic cultivar interact with termite hosts. Our molecular analyses show that although active combs are dominated by Termitomyces fungi isolated with direct Polymerase Endonuclease Restriction - Denaturing Gradient Gel Electrophoresis (PCR-DGGE), they can also harbor some filamentous fungi and yeasts only revealed by SuPER PCR-DGGE. This is the first molecular evidence of the presence of non-Termitomyces species in active combs. However, because there is no evidence for a species-specific relationship between these fungi and termites, they are mere transient guests with no specialization in the symbiosis. It is however surprising to notice that termite-associated Xylaria strains were not isolated from active combs even though they are frequently retrieved when nests are abandoned by termites. This finding highlights the implication of fungus-growing termites in the regulation of fungi occurring within the combs and also suggests that they might not have any particular evolutionary-based association with Xylaria species.  相似文献   

12.
Subterranean termites (Reticulitermes grassei) were surveyed over successive seasons in a managed eucalyptus plantation in southeastern Portugal for 26 months. Termite activity in seven diameter categories of lying dead wood was investigated by a modified line intersection method (LIS). Each item sampled was inspected and assessed for termite attack and for general (i.e. fungal) decay status using standard protocols. Line intersection is quantitative to the extent that it can link foraging and decay parameters to woody biovolume. It was found that termites selected items with larger diameter, the observed trend showing an exponential character with greater termite attack as diameter increased. Attack by termites was positively associated with prior decay by fungi. A clear positive relationship was shown between rainfall and total woody biovolume containing live termites, underlining the importance of moisture for termite activity. Subterranean termites appeared to be important wood decomposers in the woodland studied, with an average of 30% of lying dead wood branches showing signs of termite attack.  相似文献   

13.
In Lambir Hills National Park, Sarawak, Malaysia, there are four species of processional termites that coexist: Hospitalitermes hospitalis, H. lividiceps, H. rufus and Longipeditermes longipes. This paper presents the results of our investigation on the spatial distribution of nests and the foraging activities of the four species in coexistence. The results show that there are fairly marked differences in nesting sites, as well as in foraging activities, among the four species. It is noteworthy that H. rufus inhabits only the canopy area over 20 m above ground, apparently segregated from the other three species, and that their foraging activities are limited also to tree canopies over 10 m above ground. In contrast, L. longipes nests underground and forages exclusively on the forest floor. Hospitalitermes hospitalis and H. lividiceps inhabit and forage over wide areas, from the forest floor to tree canopies. The upper parts of the tree canopy (over 10 m) are also foraging territories of the secluded H. rufus, but there were no observations of simultaneous foraging of the three Hospitalitermes species in the same canopy areas.  相似文献   

14.
Cellulose digestion in lower termites, mediated by carbohydrases originating from both termite and endosymbionts, is well characterized. In contrast, limited information exists on gut proteases of lower termites, their origins and roles in termite nutrition. The objective of this study was to characterize gut proteases of the Formosan subterranean termite (Coptotermes formosanus Shiraki) (Isoptera: Rhinotermitidae). The protease activity of extracts from gut tissues (fore-, mid- and hindgut) and protozoa isolated from hindguts of termite workers was quantified using hide powder azure as a substrate and further characterized by zymography with gelatin SDS-PAGE. Midgut extracts showed the highest protease activity followed by the protozoa extracts. High level of protease activity was also detected in protozoa culture supernatants after 24 h incubation. Incubation of gut and protozoa extracts with class-specific protease inhibitors revealed that most of the proteases were serine proteases. All proteolytic bands identified after gelatin SDS-PAGE were also inhibited by serine protease inhibitors. Finally, incubation with chromogenic substrates indicated that extracts from fore- and hindgut tissues possessed proteases with almost exclusively trypsin-like activity while both midgut and protozoa extracts possessed proteases with trypsin-like and subtilisin/chymotrypsin-like activities. However, protozoa proteases were distinct from midgut proteases (with different molecular mass). Our results suggest that the Formosan subterranean termite not only produces endogenous proteases in its gut tissues, but also possesses proteases originating from its protozoan symbionts.  相似文献   

15.
The dampwood termite genus ZootermopsisEmerson contains three recognized species with four distinct and consistent hydrocarbon phenotypes. Agonistic behaviors among nonreproductive insects from colonies of the same and different hydrocarbon phenotypes were observed in the laboratory. Various combinations of soldier versus nymphs, pseudergate versus pseudergate, and soldier versus soldier encounters were used in experimental trials. Soldiers or pseudergates seldom attack individuals of the same hydrocarbon phenotype. Z. angusticollis(Hagen) (phenotype II) is typically aggressive toward phenotype III of Z. nevadensis(Hagen) but not always aggressive against phenotype I of Z. nevadensis.The variation in response is dependent on which castes are placed in the bioassay arena: soldier versus soldier bouts result in consistent aggression, while pseudergate versus pseudergate or soldier versus nymphs contacts do not. Both pseudergates and soldiers of Z. laticeps(Banks) (phenotype IV) respond agonistically toward the other three phenotypes: Z. angusticollis (II) and Z. nevadensis(I and III). Although hydrocarbon phenotypes I and III, both Z. nevadensis,are morphologically indistinguishable, agonistic behavioral responses between phenotype I and phenotype III are not equivalent to I versus I or III versus III behavioral responses. The I versus III engagements, regardless of the castes involved, display a greater proportion of avoidance and aggressive responses than I or III intraphenotype encounters. We interpret the lack of avoidance or aggressive behavior within each of the two phenotypes of Z. nevadensisand the significant avoidance and aggressive behavior between phenotypes as definite evidence of discrimination between disparate hydrocarbon phenotypes. These agonistic bioassays along with data on distinct hydrocarbon patterns and geographic distributions serve as the basis for creating two subspecies of Z. nevadensis: Z. n. nevadensis(Hagen) and Z. n. nuttingiHaverty and Thorne, ssp. nov.  相似文献   

16.
A reappraisal of the zoogeography and systematics of Asian colobines demonstrates marked discontinuities in their distribution. The Bornean proboscis monkey is separated by Sumatra from its sole congener on the Mentawai Islands. Pygathrix species have a discontinuous distribution at the range limit of the Asian Colobinae. The existence in the Himalayas of some disjunct relatives of the south Indian fauna, has obscured a wider disjunction in which for example, the hooded black leaf monkey, Semnopithecus johnii, has one subspecies in southern India and another in north Vietnam. A closely related Vietnamese leaf monkey is a subspecies of the otherwise Indonesian S. auralus. Presbytis comata is disjunct between west Java, northern Sumatra and northern Borneo. The Mentawai Islands P. potenziani is closely related. Biogeographic parallels imply a common cause and previous continuity across the intervening areas. The only wholly compatible explanation is that the disjunct areas alone retained adequate moisture and temperature to support their endemic biota during a cool drought. That not only genera, but species are disjunct, indicates such conditions prevailed recendy, and are probably attributable to the Pleistocene glaciations. The supposition that its maritime climate shielded Asian rainforest from the glacial drought known to have partially deforested Africa and South America, is inapplicable to the Indian subcontinent, and ignores the climatic effects of the emergence of the Sunda and the Sahul shelves. Such known influences, the distribution of drought indicator plants, fossil plants and fossil mammals, grassland birds and freshwater fish, and the anatomical specializations of Nasalis confirm the instability of the Asian environment. The absence of endemic representatives of certain primates in north Sumatra implies the occurrence of two cold droughts. Available evidence appears to correlate the deforestations with the abrupt curtailment of glacial Stages 7 and 5, at about 190 000 years BP and about 80 000 years BP. The greater significance of climatic than topographical barriers in delineating the Oriental zoogeographic region, and a rapid speciation rate, is implied. Morphological change is evidently generated by geographic dispersal, rather than geographic isolation.  相似文献   

17.
Dampwood termites in the genus Zootermopsis inhabit forested areas in western North America. To better understand the colony composition and breeding structure of Zootermopsis, we identified polymorphic microsatellite loci to use in population analysis. Microsatellite loci were isolated from Zootermopsis nevadensis nevadensis (Hagen); however, all primers amplified homologous loci in Zootermopsis angusticollis (Hagen) and Zootermopsis nevadensis nuttingi (Hagen). Twelve loci were polymorphic in one or more of the above subspecies and species. The number of alleles per locus ranged from one to six, with some allelic differences among subspecies and species. We are currently utilizing the microsatellite markers to investigate the population genetics of Zootermopsis.  相似文献   

18.
We interpret an unusual left M 3 attributed to Pongo from the Late Middle Pleistocene of Thailand to be an abnormal tooth rather than a supernumerary molar. Its peculiar morphology cannot be related to classical known causes that affect the dental germ: Gemination, schizodontia, synodontia. The ontogenic mechanism that might have led to the morphology of the tooth perhaps reflects stress related to a phase of marked climatic changes during the Late Middle Pleistocene in Southeast Asia.  相似文献   

19.
Blood-feeding invertebrates are emerging model taxa in biodiversity assessments, both as indicators of mammal abundance and also as sources of mammal DNA for identification. Among these, terrestrial leeches arguably offer the greatest promise; they are abundant and widespread in the humid tropics, and their blood meals can be easily assayed to establish diet. Unfortunately, terrestrial leeches are understudied, with little known about their ecology and behavior. Such information is needed to evaluate their utility as ecological indicators and to account for potential sampling biases that might arise from habitat preferences. By combining occupancy modeling and thermal tolerance assays, we determined the factors affecting species occurrence in the related terrestrial brown (Haemadipsa sumatrana) and tiger leech (Haemadipsa picta), both of which are widespread in tropical forests in Southeast Asia. We sampled both species across a degraded forest landscape in Sabah, Borneo, in wet and dry seasons, associating occurrence with habitat-level metrics. We found that, for both species, detection probability increased with canopy height regardless of season. Additionally, increased vegetation heterogeneity had a strong negative influence on brown leech occurrence in the dry season, implying an interaction between vegetation structure and climate. However, we found no difference in physiological thermal tolerance (CTMAX) between the two species. Finally, using a reduced dataset, we found a small improvement in brown leech model fit when including mammal abundance. Our results suggest that the presence of terrestrial leeches may act as useful ecological indicators of habitat quality and potentially mammalian abundance. Abstract in Indonesia is available with online material.  相似文献   

20.
The Atlantic Forest of South America is one of the most degraded tropical forests and the cultivation of sugarcane is considered one of the main causes. In humid forests termites stand out with regard to their abundance and functional importance. The present study aimed to compare termite assemblages of fragments of the Atlantic Forest with that of the sugarcane matrices that surround them. Collections were performed in two sugarcane plantations in Northeast Brazil. In each plantation a fragment of Atlantic Forest and an adjacent sugarcane field were sampled using a standardized termite sampling protocol. A total of 39 species and 302 encounters were recorded. Species richness, relative abundance and composition differed significantly between forests and the matrices, with the presence of exclusive species in each environment—25 in the forests and seven in the matrices. Soil feeding species of the subfamily Apicotermitinae and species of open areas were found in the matrices. There was a marked difference between the assemblages of the matrices, possibly due to soil characteristics. The majority of the species found in the matrices do not cause damage to the crop, but instead act in the processes of soil decomposition and formation, thereby contributing to increased productivity.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号