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1.
We studied the long-term (23-24 years) species turnover and succession of epigaeic beetle assemblages (Coleoptera: Carabidae, incl. Cicindelinae) in three remnant habitats [cottonwood (Populus spp.) and oak (Quercus spp.) stands, and old fields] that are embedded within highly urbanized areas in central Minnesota. A total of 9,710 beetle individuals belonging to 98 species were caught in three sampling years: 1980, 1981 and 2005 in pitfall traps in identical locations within each habitat. Results indicate that there were 2-3 times greater trap catches in 2005 than in 1980 (cottonwood and oak stands, and old fields) and 1.4-1.7 times greater species diversity of beetles in 2005 than in the 1980-1981 suggesting increased habitat association by beetles over time. Although there were no significant differences in catches between 2005 and 1981 (only cottonwood stands and old fields), there was a trend where more beetles were caught in 2005. At the species-level, 10 times more of an open-habitat carabid species, Cyclotrachelus sodalis sodalis LeConte, was caught in 2005 than in 1980. However, trap catches of five other abundant carabid species [Pterostichus novus Straneo, Platynus decentis (Say), Platynus mutus (Say), Calathus gregarius (Say), and Poecilus lucublandus lucublandus (Say)] did not change indicating population stability of some beetle species. These remnant habitats were increasingly colonized by exotic carabid species as Carabus granulatus granulatus Linneaus, Clivina fossor (Linneaus) and Platynus melanarius (Illiger), that were trapped for the first time in 2005. Species composition of epigaeic beetles was quite distinct in 2005 from 1980 with 39 species reported for the first time in 2005, indicating a high turnover of assemblages. At the habitat-level, greatest species diversity was in cottonwood stands and lowest was in old fields, and all habitat types in 2005 diverged from those in 1980s, but not cottonwood stands in 1981. As our sampled areas are among some of the last remnants of the original oak savanna habitats in central Minnesota, we hypothesize that conservation of these sites may be critical to maintaining epigaeic beetle assemblages under increased urbanization pressure.  相似文献   

2.
The efficiency of fenced pitfall traps for estimating the density of commonly occurring epigeal predatory beetles was examined using mark-release-recapture. Most beetles of those recovered were recaptured within one week of their release. For seven of the ten species tested recapture rates were over 70%, with higher rates for the larger species. The predatory arthropod species composition captured using fenced pitfall traps was compared to unfenced pitfall traps in winter wheat, spring barley and winter oilseed rape. Compositional analysis revealed that the dominance structure of seven carabid beetle (Coleoptera: Carabidae) taxa differed between the trap types and month of sampling in winter wheat and spring barley, but differences were small with the exception of a few taxa. Linear relationships between the two techniques were found for some carabid and rove beetles (Coleoptera: Staphylinidae). The dominance structure of seven linyphiid spider (Araneae: Linyphiidae) taxa differed between the two trap types in wheat but not barley, although large differences were restricted to two taxa. No linear relationships between the two techniques were found for any of the Linyphiidae examined. Rove beetles were more effectively sampled using the fenced compared to unfenced pitfall traps.  相似文献   

3.
R. L. Pressey  P. Adam 《Plant Ecology》1995,118(1-2):81-101
Studies of wetlands in Australia, as in other countries, have taken a wide variety of approaches to defining, surveying and classifying these environments. Past and current approaches in Australia are reviewed for each of the States and Territories which provide the context for much of the natural resource investigation in the country. While there are obvious advantages of national, and perhaps international, agreement on definition and types of wetlands, a variety of approaches to inventory and classification will always be necessary for particular purposes. More fundamental than general agreement on approaches is the need for wetland scientists and managers to maximise the accuracy of survey information, to test the assumptions involved in the use of classifications, and to ensure that the classifications they use are the most appropriate for their purposes. The issue of a global wetland classification scheme is discussed on the basis of a representative range of views by Australian wetland workers.  相似文献   

4.
5.
Behavioural responses of three linyphiid spiders to pitfall traps   总被引:1,自引:0,他引:1  
The behaviour of three linyphiid spider species (Araneae: Linyhiidae) towards pitfall traps was investigated in an experimental arena. Capture efficiencies were low with a mean of between 16 and 57 traps being encountered before spiders were caught. Survival time, trap encounter rate, trap entry rate and reactions towards vegetation were all found to be species-specific. These behaviours are considered to affect differentially pitfall trap efficiency and may partially explain the lack of clear relationship between pitfall trap catch and density found in published studies.  相似文献   

6.
Bats account for 30% of mammal diversity in SE Asia and are potential bioindicators of wider biodiversity impacts resulting from habitat loss and climate change.As existing sampling techniques in the region typically fail to record bats that habitually fly in open areas and at higher altitudes,current inventory efforts are less than comprehensive.Acoustic sampling with bat detectors may help to overcome these limitations for insectivorous bats,but has yet to be tested in mainland SE Asia.To do so,we sampled...  相似文献   

7.
Lesticus finisterrae (Carabidae: Pterostichini) sp. n. (type locality: Finisterre Range, Papua New Guinea), is described and characters to differentiate it from other “Trigonotomi” species are given. A key to the genera of pterostichine-like Harpalinae of the island, including all genera of Morionini, Cratocerini, Drimostomatini, Abacetini, Loxandrini and Pterostichini, is provided. The genus Rhytisternus (Pterostichini) is for the first time reported from New Guinea, represented by the likely adventive species Rhytisternus laevis (Macleay). The previously unknown male of Stegazopteryx ivimkaensis Will (Drimostomatini) is described.  相似文献   

8.
We used pitfall traps to sample ground beetles on sandbars along a small woodland stream and in the adjacent floodplain forest (Oglethorpe Co., GA, USA). We captured a total of 1,477 ground beetles representing 41 species. Twenty-two species were exclusive to sandbars, while eight were found only in the forested habitat. Ground beetles were captured in significantly greater numbers from sandbars, especially Brachinus janthinipennis and Omophron americanum. The B. janthinipennis record represents a new state record for the species. This study demonstrates that many unique species can be found in specialized microhabitats and emphasizes the need for biodiversity assessment surveys to include a wide range of these microhabitats within a survey area. In addition, it appears that many generalist forest species might use sandbars seasonally to exploit available resources. The U.S. Government's right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.  相似文献   

9.
Tiger beetles (Insecta: Coleoptera: Cicindelidae) often occupy small patches of suitable habitat in otherwise unsuitable landscapes. Such patches are easily overlooked, which may lead to underestimates of both the number of occurrences and the overall population size. In this study, simple World Wide Web-based tools (Google Earth and Microsoft Terraserver) were used to search high-resolution satellite imagery for patches of suitable habitat for globally and regionally rare tiger beetles on a 3,278 ha wildlife refuge in Maryland, USA. This tract is largely forested but contains scattered small open areas of sand and clay soils that are potential habitat for tiger beetles of conservation concern. Visual inspection of remotely sensed imagery resulted in the identification of 19 potential habitat patches, 15 of which yielded tiger beetle populations when surveyed on the ground. The number of species of tiger beetles recorded from this tract was increased from 3 to 8 and two new sites were discovered for the state sensitive species Cicindela scutellaris rugifrons Dejean. In addition, a small population of C. splendida Hentz was discovered, a species last reported from Maryland in 1948. The technique described here shows great promise for locating small patches of potential tiger beetle habitat in otherwise unsuitable landscapes.  相似文献   

10.
Nitidulid beetles (Coleoptera) are considered to be serious pests of date palms throughout the world. They attack ripe fruit, causing it to rot, and damage is reflected in both reduced yield and lower fruit quality. The present study was aimed at an evaluation of the susceptibility to different sap beetles to entomopathogenic nematodes. We further tested nematode efficacy in pots filled with soil infested by third instar larvae of the two beetle species. In Petri dish assay, mortality levels of Carpophilus humeralis and C. hemipterus exposed to Heterorhabditis sp. IS-5 strain indicated that the latter is less susceptible to nematode infection. Exposure of both sap beetle species to different nematode strains gave moderate levels of mortality (35-65%) with the heterorhabditid strains HP88, IS-5 and IS-25. The IS-12 strain of Heterorhabditis sp. showed poor virulence (<35% mortality) against larvae of C. humeralis as well as larvae and pupae of C. humipterus. The nematode species S. riobrave showed moderate virulence (35-65%) mortality to larvae and pupae of S. humeralis as well as to larvae of C. hemipterus . Exposure of C. hemeralis to different concentrations of Heterorhabditis sp. IS-5 in pots containing soil resulted in high mortality (>65%). In contrast, the lower concentrations (500 and 1000 nematodes/pot) caused low mortality (35%) of C. hemipterus . Other heterorhabditid strains caused 95-100% mortality of C. humeralis in pot assay. The HP88 strain of H. bacteriophora and the Tx strain of Steinernema riobrave showed poor effectiveness. Incubation of different nematode strains with the C. humeralis larvae at high temperature (32 C) resulted in an increase in insect mortality with the IS-12 and IS-21 strains. Reduced mortality was recorded with the HP88 strain treatment at the higher temperature. The IS-5 and IS-12 strains were equally effective in all three soil types tested, whereas the IS-19 strain was more effective in the Almog type soil than in the others.  相似文献   

11.
Berend Aukema 《Oecologia》1991,87(1):118-126
Summary In two successive years the fecundity of the carabid beetles Calathus (Neocalathus) cinctus, C. (N.) melanocephalus and C. (N.) mollis was studied in relation to wing-morph and temperature. Differences were found between the three species in both egg production and timing and length of the oviposition period. In all species the fecundity of laboratory bred beetles was significantly higher than that of females collected in the field. Long-winged females of both cinctus and melanocephalus had significantly higher egg production than short-winged females, and they also tended to produce eggs over a longer period. In mollis only the fecundity of the long-winged morph was established. The observed lower relative fitness of the short-winged morph in both cinctus and melanocephalus contradicts the supposed increase of the frequency of this morph in ageing, more or less isolated, populations of these species. The loss of long-winged genotypes, resulting from flight activities, is considered the most plausible cause of the increase of short-winged beetles in ageing populations. The higher fecundity of macropterous females makes them especially suited for (re)establishing populations.Communication No. 429 of the Biological Station WijsterPresent address and address for offprint requests: Kortenburg 31, NL-6871 ND Rentum  相似文献   

12.
Based on the examination of newly collected material and additional specimens housed in Chinese collections, our knowledge of Gastroserica Brenske, 1897, is expanded. Here, seven new species are described, including habitus photographs and illustrations of the male genitalia: Gastroserica haoyui sp. n. (China: Zhejiang Prov.), G. fengduana sp. n. (China: Sichuan Prov.), G. wenzhui sp. n. (China: Guangxi Prov.), G. damingshanica sp. n. (from China: Guangxi Prov.), G. jinxiuensis sp. n. (China: Guangxi Prov.), G. liboensis sp. n. (China: Yunnan Prov.) and G. carolusi sp. n. (Laos). Additionally, we provide a distribution map of the new taxa and new distribution records of the known taxa.  相似文献   

13.
We compared the response of ground beetles (Coleoptera: Carabidae) to the creation of canopy gaps of different size (0.13, 0.26, and 0.50 ha) and age (1 and 7 years) in a bottomland hardwood forest (South Carolina, USA). Samples were collected four times in 2001 by malaise and pitfall traps placed at the center and edge of each gap, and 50 m into the surrounding forest. Species richness was higher at the center of young gaps than in old gaps or in the forest, but there was no statistical difference in species richness between old gaps and the forests surrounding them. Carabid abundance followed the same trend, but only with the exclusion of Semiardistomis viridis (Say), a very abundant species that differed in its response to gap age compared to most other species. The carabid assemblage at the gap edge was very similar to that of the forest, and there appeared to be no distinct edge community. Species known to occur in open or disturbed habitats were more abundant at the center of young gaps than at any other location. Generalist species were relatively unaffected by the disturbance, but one species (Dicaelus dilatatus Say) was significantly less abundant at the centers of young gaps. Forest inhabiting species were less abundant at the centers of old gaps than in the forest, but not in the centers of young gaps. Comparison of community similarity at various trapping locations showed that communities at the centers of old and young gaps had the lowest similarity (46.5%). The community similarity between young gap centers and nearby forest (49.1%) and old gap centers and nearby forest (50.0%) was similarly low. These results show that while the abundance and richness of carabids in old gaps was similar to that of the surrounding forest, the species composition between the two sites differed greatly.  相似文献   

14.
1 Sawyer beetles (Coleoptera: Cerambycidae) and metallic wood‐boring beetles (Coleoptera: Buprestidae) attack recently killed or felled trees. They are attracted to potential hosts by volatiles and possibly by visual cues. We examined traps of six different designs to determine the role of silhouette and shape in the capture of pine sawyer beetles, Monochamus L. 2 Traps with a round black cylinder, a single vane (clear or black), or cross vanes (clear or black) all mounted above a pan were compared to an open pan. Each pan contained soapy water to retain insects. 3 Traps with a black silhouette were significantly more effective in capturing male and female Monochamus scutellatus (Say) than traps with or without clear vanes. For both sexes of M. mutator LeConte, pan traps were as effective as traps with a black silhouette. Silhouette was not important for the capture of male and female M. notatus (Drury). Trap catches for the six trap types were not significantly different for male Buprestis maculativentris Say. 4 A pan trap with a black silhouette is recommended for general use in capturing wood‐boring cerambycids and buprestids.  相似文献   

15.
Radiolabeled monoclonal antibodies (mAb) have demonstrated measurable antitumor effects in hematologic malignancies. This outcome has been more difficult to achieve for solid tumors due, for the most part, to difficulties in delivering sufficient quantities of mAb to the tumor mass. Previous studies have shown that nonlytic levels of external beam radiation can render tumor cells more susceptible to T cell-mediated killing. The goal of these studies was to determine if the selective delivery of a radiolabeled mAb to tumors would modulate tumor cell phenotype so as to enhance vaccine-mediated T-cell killing. Here, mice transgenic for human carcinoembryonic antigen (CEA) were transplanted with a CEA expressing murine carcinoma cell line. Radioimmunotherapy consisted of yttrium-90 (Y-90)-labeled anti-CEA mAb, used either alone or in combination with vaccine therapy. A single dose of Y-90-labeled anti-CEA mAb, in combination with vaccine therapy, resulted in a statistically significant increase in survival in tumor-bearing mice over vaccine or mAb alone; this was shown to be mediated by engagement of the Fas/Fas ligand pathway. Mice receiving the combination therapy also showed a significant increase in the percentage of viable tumor-infiltrating CEA-specific CD8(+) T cells compared to vaccine alone. Mice cured of tumors demonstrated an antigen cascade resulting in CD4(+) and CD8(+) T-cell responses not only for CEA, but for p53 and gp70. These results show that systemic radiotherapy in the form of radiolabeled mAb, in combination with vaccine, promotes effective antitumor response, which may have implications in the design of future clinical trials.  相似文献   

16.
Increased interest in biomass harvesting for bioenergetic applications has raised questions regarding the potential ecological consequences on forest biodiversity. Here we evaluate the initial changes in the abundance, species richness and community composition of rove (Staphylinidae) and ground beetles (Carabidae), immediately following 1) stem-only harvesting (SOH), in which logging debris (i.e., tree tops and branches) are retained on site, and 2) whole-tree harvesting (WTH), in which stems, tops and branches are removed in mature balsam fir stands in Quebec, Canada. Beetles were collected throughout the summer of 2011, one year following harvesting, using pitfall traps. Overall catch rates were greater in uncut forest (Control) than either stem-only or whole-tree harvested sites. Catch rates in WTH were greater than SOH sites. Uncut stands were characterized primarily by five species: Atheta capsularis, Atheta klagesi, Atheta strigosula, Tachinus fumipennis/frigidus complex (Staphylinidae) and to a lesser extent to Pterostichus punctatissimus(Carabidae). Increased catch rates in WTH sites, where post-harvest biomass was less, were attributable to increased catches of rove beetles Pseudopsis subulata, Quedius labradorensis and to a lesser extent Gabrius brevipennis. We were able to characterize differences in beetle assemblages between harvested and non-harvested plots as well as differences between whole tree (WTH) and stem only (SOH) harvested sites where logging residues had been removed or left following harvest. However, the overall assemblage response was largely a recapitulation of the responses of several abundant species.  相似文献   

17.
18.
Summary Using capillary electrophoresis, the enantiomers of a number of dansyl amino acids were resolved using native-cyclodextrin. The neutral chiral host resolved analytes possessing a negative charge at pH 9, the conditions employed in this study. Organic modifiers added to the running buffer were particularly adept at enhancing chiral recognition between the guest and host molecule in capillary electrophoresis. This work examined the effects of methanol, dimethylformamide, and acetonitrile on the resolution, migration time, and efficiency of twelve dansyl amino acids. Examples are given of the separation of racemic dansyl amino acids utilizing this technique and conditions necessary to achieve enantioselectivity.  相似文献   

19.
Summary In this study, a continuous-flow UV-induced mutation (CUM) device and the CUM device coupled to a selector (CUMS) reactor were fabricated and tested for their ability to enhance the probability of obtaining populations capable of chlorinated organic biodegradation. A mixed culture of bacteria were used as the starting strain for both the CUM and CUMS processes. Populations were obtained from the CUM and CUMS systems capable of 4-chlorobenzoic acid, 2,4-dichlorobenzoic acid and chlorendic acid biodegradation. Non-UV irradiated population served as controls for the experiments and did not demonstrate chlorinated organic biodegradation over the test duration.  相似文献   

20.
Abstract The south-east Asian genus Hoplosaenidea Laboissière is recognised in Australia for the first time, with a single species, scutellata sp. n., occurring in north Queensland and New Guinea. A key is provided for identification of the Australian genera of Galerucini.  相似文献   

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