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1.
When members of the two termite species Reticulitermes santonensis and Reticulitermes lucifugus grassei were placed together, each species acquired some of the allospecific cuticular products. When living individuals of each of these two species were placed together, their cuticular hydrocarbon profiles changed very quickly, since it was within the first two hours of cohabitation that they differed most from those of the corresponding control individuals. After the first two hours, the profiles of the R. santonensis individuals continued to change only very little if at all, whereas 24h later, the process of change continued in the R. lucifugus grassei individuals until their profiles resembled those of the mixed R. santonensis individuals more than their own original profiles. The profiles of the R. l. grassei individuals therefore underwent a greater change than those of the R. santonensis individuals during the period of cohabitation. The fact that similar results were obtained when dead members of these two species were placed together suggests that this difference in the adsorption of allospecific hydrocarbon by the cuticles of the members of the two species cannot be attributable to any behavioural differences, but to differences in physico-chemical composition of the cuticles between the two species.  相似文献   

2.
Taxonomy and phyletic relationships of the European termites of the holarctic genus Reticulitermes are highly debated and poorly known. Sequencing analyses of the complete cytochrome oxidase subunit II and of a fragment of 16S rDNA mitochondrial genes were performed on 21 Italian and French populations. Distance, parsimony, and maximum-likelihood evaluations on single and combined data sets confirm the presence in central peninsular Italy of R. lucifugus lucifugus, but demonstrate that a coastal Tuscan population and the Sardinian ones pertain to the Corsican subspecies R. lucifugus corsicus, whose distribution appears therefore transtyrrenian. Northeastern Italian samples are highly differentiated from presently analyzed R. lucifugus and constitute a new entity, possibly more related to the Japanese R. speratus. Finally, the French R. santonensis and the North American R. flavipes appear strongly related, so that the supposed synonymy between the two taxa must be accepted.  相似文献   

3.
In termites, the capacity of workers to differentiate into neotenic reproductives is an important characteristic that deserves particular attention. To gain insight into the differentiation pathway, the potentialities of workers and the endocrinal changes during the formation of neotenics were compared in two sympatric termites, Reticulitermes flavipes and Reticulitermes grassei. After 1 year of development, 100% of R. flavipes worker groups produced neotenics against only 63% of R. grassei groups. The average production of female neotenics was significantly higher in R. flavipes worker groups compared with R. grassei groups and R. flavipes produced a greater proportion of female neotenics. Moreover, R. flavipes produced more offspring, not only because there were more females, but also because R. flavipes females were more productive. Moreover, the offspring produced by R. flavipes grew faster than the offspring of R. grassei. Both ecdysteroid and juvenile hormone (JH) titers varied significantly during the development of neotenics. The two species showed similar ecdysteroid titer variation patterns. However, the JH titer variation patterns strongly differed: in R. grassei, the concentration of JH increased in maturing neotenics then dropped in mature neotenics, whereas in R. flavipes, the level of JH was significantly higher than in R. grassei and remained constantly high in mature neotenics. Overall, these results suggest that these two species differ strongly in many life-history traits as well as in the physiological control of their caste differentiation system. Possible origins and mechanisms of such interspecific variations are discussed, as well as their evolutionary and ecological consequences.  相似文献   

4.
Chemical, i.e. cuticular hydrocarbons, and molecular data were used to probe the phylogeography of Reticulitermes termites collected from various parts of France, Spain and Portugal. Phylogenetic relationships were inferred from sequences of the internal transcribed spacer (ITS2) of nuclear ribosomal RNA genes as well as from two partial mitochondrial DNA segments, the cytochrome oxidase II gene and a sequence combining the tRNA-Leu gene and fragments of the NADH dehydrogenase I and ribosomal 16S genes. Two species, namely, R. grassei and R. banyulensis, were identified based on an analysis of cuticular hydrocarbons and the identification was confirmed by ITS2 haplotyping. However, phylogeny based on the analysis of mitochondrial DNA was not completely in agreement with the conclusions drawn from the chemical and nuclear data. An analysis of 56 R. grassei colonies revealed intraspecific differentiation into two major lineages with distinct geographical ranges. Whereas analysis of cuticular hydrocarbons showed that R. banyulensis was chemically distinct from R. grassei, analysis of mitochondrial DNA showed its close kinship with the R. grassei lineage occurring in southern Spain. This kinship could be explained by their evolution from a common polymorphic ancestor species in this ice age refugium.  相似文献   

5.
Summary: The termites Reticulitermes santonensis (Rs) and R. lucifugus (Rl) were first regarded as different species (Feytaud, 1924) and then as the same species (Buchli, 1958). In later studies, Clément (1978, 1986) and Bagnères et al. (1990) used morphological and chemical (cuticular hydrocarbons) criteria to show that they actually are two distinct species. Feytaud (1924) and Bagnères et al. (1990) suggested that Rs could have originated from a North American population of R. flavipes that was introduced into Europe. The present study examined the distribution and reproductive cycle of Rs and an Rl sup-species, Rl grassei (Rlg), which are partly sympatric in southwest France. In the wild, Rs has an aggregated distribution related to human surroundings (past or present), i.e. populations are either dense or entirely absent. Conversely, Rlg is distributed randomly (from dense to few) throughout its range. For example, Rs is not found in towns within the Landes Forest, an area in southwest France that remained economically depressed and sparsely settled until after 1850 (Sargos, 1997), while Rlg is quite common there. Their respective reproductive strategies show that Rs populations spread through budding (swarms are scarce and many brachypterous nymphs and neotenics are found), whereas Rlg populations reproduce by both swarming and budding. It is likely that Rs is an introduced species and Rlg a native one that has reached its northern limits in France. A closer examination of North American Reticulitermes species, particularly R. flavipes, might reveal a relationship with the European species.  相似文献   

6.
DNA sequence comparisons of the mitochondrial COII, 16S, and 12S rRNA genes were used to infer phylogenetic relationships among the six known US Reticulitermes species (Reticulitermes flavipes, Reticulitermes arenincola, Reticulitermes tibialis, Reticulitermes hageni, Reticulitermes virginicus, and Reticulitermes hesperus) and the closely related European species Reticulitermes santonensis. The interspecific pairwise sequence divergence, based on uncorrected "p" distance, varied up to 10% across the COII, 4.9% across the 16S, and 3% across the 12S fragments. Phylogenetic trees were constructed using maximum parsimony, likelihood, and distance methods. The combined results suggest several phylogenetic relationships including: (i) R. flavipes, R. arenincola, and European R. santonensis are possibly conspecific; (ii) R. virginicus and R. hageni are closely related species; and (iii) R. tibialis and R. hesperus are closely related species. Interestingly, while there is apparent synonymity between R. flavipes and R. arenincola by DNA sequence, there are clear morphological differences in the soldier caste. This finding suggests a combination of molecular and morphological approaches are necessary for accurate species identification. These data lend resolution to the complex problem of Reticulitermes systematics, and will assist future efforts directed toward characterizing species distribution and ecology.  相似文献   

7.
Reticulitermes santonensis is a subterranean termite that invades urban areas in France and elsewhere where it causes damage to human-built structures. We investigated the breeding system, colony and population genetic structure, and mode of dispersal of two French populations of R. santonensis. Termite workers were sampled from 43 and 31 collection points, respectively, from a natural population in west-central France (in and around the island of Oleron) and an urban population (Paris). Ten to 20 workers per collection point were genotyped at nine variable microsatellite loci to determine colony identity and to infer colony breeding structure. There was a total of 26 colonies, some of which were spatially expansive, extending up to 320 linear metres. Altogether, the analysis of genotype distribution, F-statistics and relatedness coefficients suggested that all colonies were extended families headed by numerous neotenics (nonwinged precocious reproductives) probably descended from pairs of primary (winged) reproductives. Isolation by distance among collection points within two large colonies from both populations suggested spatially separated reproductive centres with restricted movement of workers and neotenics. There was a moderate level of genetic differentiation (F(ST) = 0.10) between the Oleron and Paris populations, and the number of alleles was significantly higher in Oleron than in Paris, as expected if the Paris population went through bottlenecks when it was introduced from western France. We hypothesize that the diverse and flexible breeding systems found in subterranean termites pre-adapt them to invade new or marginal habitats. Considering that R. santonensis may be an introduced population of the North American species R. flavipes, a breeding system consisting primarily of extended family colonies containing many neotenic reproductives may facilitate human-mediated spread and establishment of R. santonensis in urban areas with harsh climates.  相似文献   

8.
Each of the termite species Reticulitermes santonensis and Reticulitermes lucifugus grassei has its own particular cuticular chemical profile. When members of the two species are placed together to form artificially mixed species groups, their chemical profiles undergo changes: Each species acquires all the hydrocarbons which initially characterized the other species. When the members of a mixed group which had been kept together for 24 h were split into two homospecific groups, the cuticular profiles of the members of both groups immediately showed a sharp drop in both the homospecific and allospecific components. In R. santonensis, the homospecific hydrocarbons subsequently increased in quantity, reaching values which were higher on the 33rd day after the separation than those initially recorded in this species; whereas in R. lucifugus grassei, the homospecific hydrocarbon proportions were still lower on the 33rd day than the initial values. In both species, the allospecific hydrocarbon levels began to increase sharply on the 5th day after separation, and the homospecific products still showed no tendency to return to the initial proportions 33 days after separation. In the light of these results, some hypotheses are put forward as to what mechanisms might posibly regulate the hydrocarbon profiles of these two species. Arch. Insect Biochem. Physiol. 35:237-259, 1997.© 1997 Wiley-Liss, Inc.  相似文献   

9.
Nobre T  Nunes L  Eggleton P  Bignell DE 《Heredity》2006,96(5):403-409
The genus Reticulitermes has a Holartic distribution and is widely represented in southern Europe. It is established in Portugal, across the full range of ambient environmental conditions, using different types of wood resources, as available, and nesting ubiquitously in many types of soil. Sequencing of part of the mtDNA COII gene revealed that all the specimens sampled on a north-south transect of the country were Reticulitermes grassei (considered synonymous with R. lucifugus grassei). Nevertheless, an association between the genetic and the geographical distances of sampled specimens was shown, leading to the conclusion that discrete termite populations have differentiated in situ. The geographic component of the genetic polymorphism should be the subject for further research.  相似文献   

10.
The alarm behavior of worker and soldier castes of four European subterranean termite species of the genus Reticulitermes (R. santonensis, R. lucifugus, R. grassei, R. banyulensis) is described. In petri dish bioassays we presented filter papers with squashed soldier heads as an odor source to trigger a alarm reaction. Untreated filter papers were used as controls. The behavioral patterns were alike for all four species. In the control situation (no alarm), only occasional workers and few soldiers were seen walking in the petri dish. When the odor source was presented, a general state of alertness was observed, showing as higher activity and presence, zigzag running, antennation of nestmates, jittering and jerking, mandible snapping, head-banging, and attraction to the odor source. Workers were attracted within a few seconds (6.9–13.4 s); soldiers followed much later (18.5–64.6 s). Both workers and soldiers inspected the odor source only briefly (workers for 8.7–12.8 s, soldiers for 10.0–19.5 s), with the exception of R. santonensis, where soldiers stayed an average of 209.8 s. The number of individuals, of 50 workers and 3 soldiers, near the odor source averaged 6.0–9.2 workers and 1.2–2.3 soldiers. The presence of workers is crucial: without workers, a significant alarm reaction in soldiers could not be induced. The roles of soldier and worker castes of Reticulitermes species within alarm communication and the origin and nature of possible alarm signals are discussed.  相似文献   

11.
The transport of lipids constitutes a vital function in insects and requires the plasma lipoprotein lipophorin. In all insects examined to date, cuticular hydrocarbons are also transported through the hemolymph by lipophorin, and in social insects they play important roles not only in water proofing the cuticle but also in nestmate recognition. High-density lipophorin (HDLp), isolated from Reticulitermes flavipes plasma by KBr gradient ultracentrifugation, contains 66.2% protein and 33.8% lipids; hydrocarbons constitute its major neutral lipid (20.4% of total lipids). Anti-lipophorin serum was generated in rabbit and its specific association with lipophorin, and not with any other plasma proteins, was verified with Western blotting. Immunoprecipitation also confirmed that this antibody specifically recognizes lipophorin, because all hemolymph hydrocarbons of the termites R. flavipes and R. lucifugus and the cockroach Supella longipalpa, which associate only with lipophorin, were recovered in the immunoprecipitated protein. Cross-reactivity of the antiserum with lipophorin from related species was investigated by double immunodiffusion with 10 termite species in the genera Reticulitermes, Coptotermes, Zootermopsis, and Kalotermes, and with five cockroach species. Involvement of lipophorin in hydrocarbon transport was shown by injecting HDLp antiserum into Zootermopsis nevadensis and then monitoring the de novo biosynthesis of hydrocarbons and their transport to the cuticular surface; the antiserum significantly disrupted hydrocarbon transport. ELISA revealed a gradual increase in the lipophorin titer in successively larger R. flavipes workers, and differences among castes in lipophorin titers were highest between nymphs and first instar larvae.  相似文献   

12.
The Holoarctic termite genus Reticulitermes is widely distributed in Europe. A new Reticulitermes species, R. sp. nov, was recently found in France and Italy. Its phylogenetic position was investigated using a 743-bp fragment of mitochondrial 16S rRNA-ND1 genes and 382-bp of the nuclear ITS2 region. Phylogenies for these sequences were estimated by neighbor-joining, maximum-parsimony and maximum-likelihood analysis. The results strongly supported a relationship between R. sp. nov. and the termite species from the eastern Mediterranean area including Reticulitermes balkanensis from the Balkans, Reticulitermes lucifugus from Turkey and Reticulitermes clypeatus from Israel. The hypothesis of a relationship between R. sp. nov. and the Japanese Reticulitermes speratus was rejected by parametric bootstrap. The current distribution of R. sp. nov. could be linked to postglacial colonization routes between Balkan refuge and northern regions.  相似文献   

13.
A DNA-based system for the identification of Reticulitermes flavipes (Koller) was established based on the following criteria: adequate molecular variation, comprehensive specimen sampling, explicit morphological species identification, and cladistic analysis. Termite soldiers were identified by labral shape, and these specimens and associated pseudergates were used in subsequent molecular analyses. Mitochondrial DNA from the AT-rich region was sequenced for 173 R. flavipes, Reticulitermes hageni Banks and Reticulitermes virginicus (Banks) soldiers and pseudergates collected from several widely dispersed Texan localities. Cladistic analysis was performed after exploration of an optimal sequence alignment inclusive of DNA sequences from Texas and published sequences from Georgia and Canada. Among the Texan individuals, 29, 5, and 1 mitochondrial DNA haplotypes were identified respectively with R. flavipes, R. hageni, and R. virginicus. One haplotype from El Paso likely represented a different Reticulitermes species. Species were monophyletic; however, individual relationships were unresolved in a strict consensus of 700 most parsimonious trees. Texas haplotypes were isolated by distance, and a correlation between genetic and geographic distance was observed among the Texas, Georgia, and Canada haplotypes. These results suggest that the methods outlined in this study will allow for the identification of R. flavipes from localities between Texas and Canada.  相似文献   

14.
Biological invasions are recognized as a major threat to both natural and managed ecosystems. Phylogeographic and population genetic analyses can provide information about the geographical origins and patterns of introduction and explain the causes and mechanisms by which introduced species have become successful invaders. Reticulitermes flavipes is a North American subterranean termite that has been introduced into several areas, including France where introduced populations have become invasive. To identify likely source populations in the USA and to compare the genetic diversity of both native and introduced populations, an extensive molecular genetic study was undertaken using the COII region of mtDNA and 15 microsatellite loci. Our results showed that native northern US populations appeared well differentiated from those of the southern part of the US range. Phylogenetic analysis of both mitochondrial and nuclear markers showed that French populations probably originated from southeastern US populations, and more specifically from Louisiana. All of the mtDNA haplotypes shared between the United States and France were found in Louisiana. Compared to native populations in Louisiana, French populations show lower genetic diversity at both mtDNA and microsatellite markers. These findings are discussed along with the invasion routes of R. flavipes as well as the possible mechanisms by which French populations have evolved after their introduction.  相似文献   

15.
Abstract.  Wohlfahrtia magnifica (Schiner) (Diptera: Sarcophagidae) is a major cause of traumatic myiasis in livestock in Central and Eastern Europe and in countries bordering the Mediterranean. The present study explored the utility of external body characters, genitalia characters and mitochondrial DNA characters for identification of this and related species in the subfamily Paramacronychiinae. Sequence analyses of the 3' terminal 273 bp of the mitochondrial cytochrome b gene revealed two lineages of W. magnifica , one from Spain and France and the other from the rest of Eurasia, differing by only two base pairs. Phylogenetic analysis of cytochrome b showed that W. magnifica and Wohlfahrtia vigil Walker were sister species; this conclusion was not contradicted by a phylogenetic analysis of the morphological characters. Based on cytochrome b , the genetic distance between specimens of W. vigil from Europe and North America was sufficiently large to justify the recognition of more than one species. A new species, Wohlfahrtia monegrosensis , from northern Spain, was described, based on morphology and cytochrome b . A unique combination of external body characters of males or females were diagnostic for W. magnifica , the W. vigil group and Wohlfahrtia bella , but only the genitalia characters were diagnostic for all nine species studied.  相似文献   

16.
Myotis lucifugus, once among the most widespread and common bats in North America, has been forecast to be extirpated east of the Rockies in as few as 16 years by the spread of white-nose syndrome. Recent genetic research has demonstrated that this species is paraphyletic and part of a broader species complex; however, only one lineage (Myotis lucifugus lucifugus [M. l. lucifugus]) is present in eastern North America. I used molecular tools and niche modeling to validate this and investigate the role that historical biogeography has played in the phylogenetic and population genetic structure of this species to determine if the eastern subspecies represents an evolutionarily distinct population.To establish the genetic structure within M. l. lucifugus, I densely sampled maternity colonies in Minnesota and sequenced 182 individuals for a portion of cytochrome b. Phylogenetic reconstruction and a haplotype network were used to infer the relationships among mitochondrial haplotypes. Population growth statistics were calculated to determine if there was evidence of significant expansion, and an environmental niche model (ENM) was constructed based on conditions during the last glacial maximum (LGM) to illustrate potential glacial refugia. All individuals derived from a single mitochondrial lineage. Genetic evidence points to population growth starting approximately 18 kya. ENM results show that there was likely a single large southern refugium extending across the southeastern United States and possibly several isolated refugia in western North America. Myotis lucifugus lucifugus likely maintained both a large range and a large population during the peaks of the glacial cycles, and its population appears to have expanded following the retreat of the Laurentide ice sheet. This imperiled lineage likely diverged in isolation from other members of the M. lucifugus/western long-eared Myotis during the Pleistocene.  相似文献   

17.
In order to contribute to the debate about southern glacial refugia used by temperate species and more northern refugia used by boreal or cold-temperate species, we examined the phylogeography of a widespread snake species (Vipera berus) inhabiting Europe up to the Arctic Circle. The analysis of the mitochondrial DNA (mtDNA) sequence variation in 1043 bp of the cytochrome b gene and in 918 bp of the noncoding control region was performed with phylogenetic approaches. Our results suggest that both the duplicated control region and cytochrome b evolve at a similar rate in this species. Phylogenetic analysis showed that V. berus is divided into three major mitochondrial lineages, probably resulting from an Italian, a Balkan and a Northern (from France to Russia) refugial area in Eastern Europe, near the Carpathian Mountains. In addition, the Northern clade presents an important substructure, suggesting two sequential colonization events in Europe. First, the continent was colonized from the three main refugial areas mentioned above during the Lower-Mid Pleistocene. Second, recolonization of most of Europe most likely originated from several refugia located outside of the Mediterranean peninsulas (Carpathian region, east of the Carpathians, France and possibly Hungary) during the Mid-Late Pleistocene, while populations within the Italian and Balkan Peninsulas fluctuated only slightly in distribution range, with larger lowland populations during glacial times and with refugial mountain populations during interglacials, as in the present time. The phylogeographical structure revealed in our study suggests complex recolonization dynamics of the European continent by V. berus, characterized by latitudinal as well as altitudinal range shifts, driven by both climatic changes and competition with related species.  相似文献   

18.
The repellence of the plant-derived bicyclic monoterpenoid isoborneol on subterranean termites was assessed in short-term laboratory bioassays. Depending on concentration, application of isoborneol to different soil types was efficient in creating repellent soil barriers, which were not penetrated by workers of Reticulitermes santonensis De Feytaud or R. flavipes Kollar within 2 wk after adding the substance to the substrate. Isoborneol-treated barriers did not affect termite survival. The bioavailability of the active ingredient decreased with increasing clay content of the soil. Evaporation of isoborneol from treated soil increased with increasing particle size of the substrate and could be reduced by covering the soil surface.  相似文献   

19.
Temporal and spatial analyses are seldom utilized in the study of colony genetic structure, but they are potentially powerful methods which can yield novel insights into the mechanisms underlying variation in breeding systems. Here we present the results of a study which incorporated both of these dimensions in an examination of genetic structure of subterranean termites in the genus Reticulitermes (primarily R. flavipes). Most colonies of this species (70%) were simple families apparently headed by outbred primary reproductives, while most of the remaining (27% of the total) colonies contained low effective numbers of moderately inbred reproductives. Mapping the spatial distribution of colony foraging sites over time revealed that despite the high colony density, the absolute foraging boundaries of most R. flavipes colonies were persistent and exclusive of other conspecific colonies, which suggests that this species is more territorial than has been implied by laboratory studies of intraspecific aggression. Nevertheless, we found a single colony (3% of all colonies) which contained the offspring of more than two unrelated reproductives. Although other studies have also described subterranean termite colonies with a similarly complex genetic composition, we demonstrate here that such colonies can form under natural conditions via the fusion of whole colonies. This study underscores how repeated sampling from individual colonies over time and space can yield information about colony spatial and genetic structure that cannot be obtained from conventional analyses or sampling methods.  相似文献   

20.
Lactic acid bacteria have been identified as typical and numerically significant members of the gut microbiota of Reticulitermes flavipes and other wood-feeding lower termites. We found that also in the guts of the higher termites Nasutitermes arborum (wood-feeding), Thoracotermes macrothorax, and Anoplotermes pacificus (both soil-feeding), lactic acid bacteria represent the largest group of culturable carbohydrate-utilizing bacteria (3.6-5.2x10(4) bacteria per gut; 43%-54% of all colonies). All isolates were coccoid and phenotypically difficult to distinguish, but their enterobacterial repetitive intergenic consensus sequence (ERIC) fingerprint patterns showed a significant genetic diversity. Six different genotypes each were identified among the isolates from R. flavipes and T. macrothorax, and representative strains were selected for further characterization. By 16S rRNA gene sequence analysis, strain RfL6 from R. flavipes was classified as a close relative of Enterococcus faecalis, whereas strain RfLs4 from R. flavipes and strain TmLO5 from T. macrothorax were closely related to Lactococcus lactis. All strains consumed oxygen during growth on glucose and cellobiose; oxygen consumption of these and other isolates from both termite species was due to NADH and pyruvate oxidase activities, but did not result in H2O2 formation. In order to assess the significance of the isolates in the hindgut, denaturing gradient gel electrophoresis was used to compare the fingerprints of 16S rRNA genes in the bacterial community of R. flavipes with those of representative isolates. The major DNA band from the hindgut bacterial community was further separated by bisbenzimide-polyethylene glycol electrophoresis, and the two resulting bands were sequenced. Whereas one sequence belonged to a spirochete, the second sequence was closely related to the sequences of the Lactococcus strains RfLs4 and TmLO5. Apparently, those isolates represent strains of a new Lactococcus species which forms a significant fraction of the complex hindgut community of the lower termite R. flavipes and possibly also of other termites.  相似文献   

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