Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
1.
Glob Chang Biol ; 27(2): 297-311, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33064866

RESUMO

A fundamental gap in climate change vulnerability research is an understanding of the relative thermal sensitivity of ectotherms. Aquatic insects are vital to stream ecosystem function and biodiversity but insufficiently studied with respect to their thermal physiology. With global temperatures rising at an unprecedented rate, it is imperative that we know how aquatic insects respond to increasing temperature and whether these responses vary among taxa, latitudes, and elevations. We evaluated the thermal sensitivity of standard metabolic rate in stream-dwelling baetid mayflies and perlid stoneflies across a ~2,000 m elevation gradient in the temperate Rocky Mountains in Colorado, USA, and the tropical Andes in Napo, Ecuador. We used temperature-controlled water baths and microrespirometry to estimate changes in oxygen consumption. Tropical mayflies generally exhibited greater thermal sensitivity in metabolism compared to temperate mayflies; tropical mayfly metabolic rates increased more rapidly with temperature and the insects more frequently exhibited behavioral signs of thermal stress. By contrast, temperate and tropical stoneflies did not clearly differ. Varied responses to temperature among baetid mayflies and perlid stoneflies may reflect differences in evolutionary history or ecological roles as herbivores and predators, respectively. Our results show that there is physiological variation across elevations and species and that low-elevation tropical mayflies may be especially imperiled by climate warming. Given such variation among species, broad generalizations about the vulnerability of tropical ectotherms should be made more cautiously.


Assuntos
Ephemeroptera , Animais , Colorado , Ecossistema , Equador , Insetos , Temperatura , Clima Tropical
2.
Proc Natl Acad Sci U S A ; 115(49): 12471-12476, 2018 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-30397141

RESUMO

Species richness is greatest in the tropics, and much of this diversity is concentrated in mountains. Janzen proposed that reduced seasonal temperature variation selects for narrower thermal tolerances and limited dispersal along tropical elevation gradients [Janzen DH (1967) Am Nat 101:233-249]. These locally adapted traits should, in turn, promote reproductive isolation and higher speciation rates in tropical mountains compared with temperate ones. Here, we show that tropical and temperate montane stream insects have diverged in thermal tolerance and dispersal capacity, two key traits that are drivers of isolation in montane populations. Tropical species in each of three insect clades have markedly narrower thermal tolerances and lower dispersal than temperate species, resulting in significantly greater population divergence, higher cryptic diversity, higher tropical speciation rates, and greater accumulation of species over time. Our study also indicates that tropical montane species, with narrower thermal tolerance and reduced dispersal ability, will be especially vulnerable to rapid climate change.


Assuntos
Distribuição Animal , Biodiversidade , Especiação Genética , Insetos/genética , Insetos/fisiologia , Altitude , Animais , Temperatura , Clima Tropical
3.
Ecol Appl ; 30(1): e02005, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31532056

RESUMO

More than a century of dam construction and water development in the western United States has led to extensive ecological alteration of rivers. Growing interest in improving river function is compelling practitioners to consider ecological restoration when managing dams and water extraction. We developed an Ecological Response Model (ERM) for the Cache la Poudre River, northern Colorado, USA, to illuminate effects of current and possible future water management and climate change. We used empirical data and modeled interactions among multiple ecosystem components to capture system-wide insights not possible with the unintegrated models commonly used in environmental assessments. The ERM results showed additional flow regime modification would further alter the structure and function of Poudre River aquatic and riparian ecosystems due to multiple and interacting stressors. Model predictions illustrated that specific peak flow magnitudes in spring and early summer are critical for substrate mobilization, dynamic channel morphology, and overbank flows, with strong subsequent effects on instream and riparian biota that varied seasonally and spatially, allowing exploration of nuanced management scenarios. Instream biological indicators benefitted from higher and more stable base flows and high peak flows, but stable base flows with low peak flows were only half as effective to increase indicators. Improving base flows while reducing peak flows, as currently proposed for the Cache la Poudre River, would further reduce ecosystem function. Modeling showed that even presently depleted annual flow volumes can achieve substantially different ecological outcomes in designed flow scenarios, while still supporting social demands. Model predictions demonstrated that implementing designed flows in a natural pattern, with attention to base and peak flows, may be needed to preserve or improve ecosystem function of the Poudre River. Improved regulatory policies would include preservation of ecosystem-level, flow-related processes and adaptive management when water development projects are considered.


Assuntos
Ecossistema , Rios , Mudança Climática , Colorado , Movimentos da Água
4.
Ecol Lett ; 21(4): 525-535, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29430810

RESUMO

The ecological and evolutionary consequences of extreme events are poorly understood. Here, we tested predictions about species persistence and population genomic change in aquatic insects in 14 Colorado mountain streams across a hydrological disturbance gradient caused by a one in 500-year rainfall event. Taxa persistence ranged from 39 to 77% across sites and declined with increasing disturbance in relation to species' resistance and resilience traits. For taxa with mobile larvae and terrestrial adult stages present at the time of the flood, average persistence was 84% compared to 25% for immobile taxa that lacked terrestrial adults. For two of six species analysed, genomic diversity (allelic richness) declined after the event. For one species it greatly expanded, suggesting resilience via re-colonisation from upstream populations. Thus, while resistance and resilience traits can explain species persistence to extreme disturbance, population genomic change varies among species, challenging generalisations about evolutionary responses to extreme events at landscape scales.


Assuntos
Inundações , Genômica , Insetos , Animais , Colorado , Insetos/genética , Rios
5.
Zootaxa ; 5094(1): 177-195, 2022 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-35391456

RESUMO

Acroneuria Pictet, 1841 (Plecoptera: Perlidae) is a genus of stoneflies which presently includes 18 summer emerging Nearctic species. Diagnosis of species relies primarily on male aedeagal setal patterns, details of the ovum chorion, and larval dorsal maculations. Several species are morphologically cryptic in one or more life stages. In 2010, an apparently rare species, A. kosztarabi Kondratieff Kirchner, 1993, was petitioned for listing under the Endangered Species Act. A status survey conducted in 20162017 produced new specimen collections from near the type locality and surrounding areas. Examination of new material and the holotype of A. kirchneri Stark Kondratieff, 2004 demonstrates that it is a junior subjective synonym of A. kosztarabi. All life stages of A. kosztarabi are redescribed using color photographs and scanning electron microscope photomicrographs. Supporting data include maximum likelihood and pairwise genetic distance analyses based on mitochondrial cytochrome c oxidase subunit I fragment data. Acroneuria kosztarabi, previously known only from the type locality, is now reported from six states in the southeastern United States ranging from central North Carolina to western Tennessee and north to northern Virginia and northern Ohio.


Assuntos
Insetos , Neópteros , Animais , Masculino , Mitocôndrias
6.
J Med Entomol ; 58(2): 505-517, 2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33164093

RESUMO

We report 28 species of ticks (Acari: Ixodida) from Colorado (CO). We include the soft ticks (Argasidae) Argas (Argas) cooleyi Kohls and Hoogstraal, Argas (Persicargas) radiatus Railliet, Carios (Alectorobius) concanensis (Cooley and Kohls), Carios (Alectorobius) kelleyi (Cooley and Kohls), Ornithodoros (Pavlovskyella) hermsi Wheeler et al., Ornithodoros (Pavlovskyella) parkeri Cooley, Ornithodoros (Pavlovskyella) turicata (Dugès), Otobius (Otobius) lagophilus Cooley and Kohls, and Otobius (Otobius) megnini (Dugès). We include the metastriate hard ticks (Ixodidae) Dermacentor (Americentor) albipictus (Packard), Dermacentor (Dermacentor) andersoni Stiles, Dermacentor (Dermacentor) parumapertus Neumann, Dermacentor (Dermacentor) variabilis (Say), Haemaphysalis (Aboimisalis) chordeilis (Packard), Haemaphysalis (Gonixodes) leporispalustris (Packard), and Rhipicephalus (Rhipicephalus) sanguineus Latreille. Prostriate hard ticks include Ixodes (Ixodiopsis) angustus Neumann, Ixodes (Phoeloioxdes) baergi Cooley and Kohls, Ixodes (Trichotoixodes) brunneus Koch, Ixodes (Scaphixodes) howelli Cooley and Kohls, Ixodes (Phoeloioxdes) kingi Bishopp, Ixodes (Phoeloioxdes) marmotae Cooley and Kohls, Ixodes (Ixodiopsis) ochotonae Gregson, Ixodes (Phoeloioxdes) sculptus Neumann, Ixodes (Ixodiopsis) soricis Gregson, Ixodes (Ixodes) spinipalpis Hadwen and Nuttall, Ixodes (Phoeloioxdes) texanus Banks, and Ixodes (Ixodiopsis) woodi Bishopp. Argas radiatus and Ixodes brunneus represent new state records. Review of collection reports revealed that inclusion of Ixodes (Multidentatus) auritulus (Neumann), Ixodes (Phoeloioxdes) cookei Packard, Ixodes (Phoeloioxdes) marxi Banks, and Ixodes (Ixodes) pacificus Cooley and Kohls is dubious or unconfirmed and, conversely, that C. concanensis and H. chordeilis have distributions that include CO. We list an additional five species occasionally detected and 13 exotic species intercepted in CO. Tick-host associations, geographical distributions, and medical/veterinary importance are included.


Assuntos
Vetores Aracnídeos , Argas , Ixodes , Animais , Colorado , Doenças Transmitidas por Carrapatos
7.
Ecology ; 102(11): e03503, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34314030

RESUMO

Frameworks exclusively considering functional diversity are gaining popularity, as they complement and extend the information provided by taxonomic diversity metrics, particularly in response to disturbance. Taxonomic diversity should be included in functional diversity frameworks to uncover the functional mechanisms causing species loss following disturbance events. We present and test a predictive framework that considers temporal functional and taxonomic diversity responses along disturbance gradients. Our proposed framework allows us to test different multidimensional metrics of taxonomic diversity that can be directly compared to calculated multidimensional functional diversity metrics. It builds on existing functional diversity-disturbance frameworks both by using a gradient approach and by jointly considering taxonomic and functional diversity. We used previously unpublished stream insect community data collected prior to, and for the two years following, an extreme flood event that occurred in 2013. Using 14 northern Colorado mountain streams, we tested our framework and determined that taxonomic diversity metrics calculated using multidimensional methods resulted in concordance between taxonomic and functional diversity responses. By considering functional and taxonomic diversity together and using a gradient approach, we were able to identify some of the mechanisms driving species losses following this extreme disturbance event.


Assuntos
Inundações , Rios , Animais , Biodiversidade , Colorado , Insetos
8.
Zootaxa ; 4565(3): zootaxa.4565.3.7, 2019 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-31716467

RESUMO

Two new species of Anacroneuria are described. Anacroneuria bandido sp. n. is described from Coclé and Veraguas provinces of central Panama, and A. tuberculata sp. n. is proposed to provide a new name for a species previously identified from Costa Rica as A. magnirufa Jewett, 1958. New locality records are presented for eight species previously reported from Panama. The female of one species from Bocas del Toro province is described under an informal designation. There are now 26 recognized species of Plecoptera known from Panama.


Assuntos
Insetos , Animais , Costa Rica , Feminino , Panamá , Parques Recreativos
9.
Zookeys ; (819): 243-254, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30713443

RESUMO

Currently, a total of 267 stonefly species are known for Canada. The biodiversity hotspot of Canadian stoneflies is British Columbia with at least 138 species, nearly 52% of all species known from Canada. Four families, the Perlodidae, Capniidae, Chloroperlidae, and Nemouridae, contain nearly 75% of all species known to occur in Canada. The family with the fewest species represented in Canada is the Peltoperlidae. The stonefly fauna of Canada consists of two major faunal assemblages, west and east. The western clade consists of those species inhabiting Manitoba, all provinces to the west, and the three territories. The eastern clade consists of species from Ontario eastward. The two clades share only 29 species (10.9% of the Canadian total), suggesting a separate origin for each clade. The available taxonomic literature for the stoneflies of Canada is reviewed.

10.
Mitochondrial DNA B Resour ; 5(1): 152-153, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33366463

RESUMO

In this study, we sequenced the mitochondrial genome of Perlesta teaysia. The complete mitochondrial genome was 16,023 bp in length, including 37 typical genes and a control region. The overall nucleotide composition was biased toward the A/T nucleotides. All the protein-coding genes (PCGs) started with typical ATN codon as the start codon except for ND1 and ND5, which started with TTG and GTG, respectively. In addition, 11 of 13 PCGs possessed the typical stop codon TAA/TAG, whereas ND4 and ND5 terminated with an incomplete stop codon. Phylogenetic analysis suggested that P. teaysia was a sister group to Calineuria stigmatica.

11.
Sci Total Environ ; 646: 770-781, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30064103

RESUMO

The natural hydrologic processes that create and maintain the diversity of aquatic and riparian habitats along the World's streams and rivers have been profoundly altered by humans. Diversion of surface water to support production agriculture in arid and semi-arid regions has degraded ecosystems but also created potential habitat along and in canals specifically designed to transport water. The prevalence of canals and the immense amount of water used for agriculture have created these new artificial stream systems. This study demonstrates the potential for irrigation canals to support riparian and aquatic communities similar to natural streams in urban/residential and agricultural landscapes. We examined the hydrological and ecological characteristics of streams and irrigation canals in urban and agricultural landscapes in northeastern Colorado, typical of regions dominated by irrigation-supported agriculture. Flow patterns in canals depended on their size and had a range of patterns with potential ecological consequences such as rapidly rising and falling water stage, intermittent dry periods, and delayed peak and base flows compared to natural streams. Despite these hydrologic differences, the taxonomic and functional composition of riparian plant and aquatic macroinvertebrate communities indicated that ecological similarities exist between streams and canals, but are dependent, in part, on their landscape setting with stronger similarities in agricultural areas. We also tested the influence of characterizing taxa by functional groups using physiology, ecology and life history traits to explore attributes of habitats including woody canopy structure and water quality. We used a Habitat Quality Index (HQI) that combined physical and biological measures into a single index. Streams scored higher on average within agriculture and urban/residential settings compared to canals; however, one third of urban canals scored above the average of agricultural streams. This multidisciplinary study shows that irrigation canals can be valuable riparian and aquatic habitat, especially in regions with severely degraded streams.

12.
Ecol Evol ; 9(12): 7200-7212, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31380043

RESUMO

Phenological mismatches-defined here as the difference in reproductive timing of an individual relative to the availability of its food resources-occur in many avian species. Mistiming breeding activities in environments with constrained breeding windows may have severe fitness costs due to reduced opportunities for repeated breeding attempts. Therefore, species occurring in alpine environments may be particularly vulnerable.We studied fitness consequences of timing of breeding in an alpine-endemic species, the white-tailed ptarmigan (Lagopus leucura), to investigate its influence on chick survival. We estimated phenological mismatch by measuring plant and arthropods used by ptarmigan in relation to their timing of breeding.We monitored 120 nests and 67 broods over a three-year period (2013-2015) at three alpine study sites in the Rocky Mountains of Colorado. During this same period, we actively monitored food resource abundance in brood-use areas to develop year and site-specific resource phenology curves. We developed several mismatch indices from these curves that were then fit as covariates in mark-recapture chick survival models.A correlation analysis between seasonal changes in arthropod and food plant abundance indicated that a normalized difference vegetation index (NDVI) was likely the best predictor for food available to hens and chicks. A survival model that included an interaction between NDVI mismatch and chick age received strong support and indicated young chicks were more susceptible to mismatch than older chicks.We provide evidence that individual females of a resident alpine species can be negatively affected by phenological mismatch. Our study focused on individual females and did not examine if phenological mismatch was present at the population level. Future work in animal populations occurring in mountain systems focusing on a combination of both individual- and population-level metrics of mismatch will be beneficial.

13.
Insects ; 10(8)2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31416241

RESUMO

The adult male of Allokermes galliformis (Riley, 1881) (Hemiptera: Coccomorpha: Kermesidae) is described for the first time in Colorado, United States of America. This scale insect species recently emerged as a significant pest of red oaks in Colorado through its causative role in drippy blight disease. A description and illustration of the adult male characterize its key external morphological characteristics.

14.
J Am Mosq Control Assoc ; 24(2): 281-8, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18666537

RESUMO

Resistance to permethrin and the activity of metabolic enzymes were monitored in field-collected Culex tarsalis from northeastern Colorado during 2005 and 2006 and compared with a lab strain from Bakersfield, CA. Collections were made from 13 different sites within and outside of the mosquito abatement area. Resistance levels by year and early vs. late season were examined and median lethal time values and 95% confidence intervals were compared with the lab strain. Mosquitoes collected in 2005 were more resistant to permethrin than either the lab strain or mosquitoes collected in 2006. Glutathione S-transferase levels recorded in 2005 were 9-12x higher than either the lab strain or 2006 mosquitoes; activity of mixed-function oxidases was also greater. Both mechanisms may play a role in permethrin resistance or reflect nontarget exposure to other pesticides in Cx. tarsalis in northeastern Colorado.


Assuntos
Culex/enzimologia , Esterases/metabolismo , Glutationa Transferase/metabolismo , Inseticidas , Oxigenases de Função Mista/metabolismo , Permetrina , Animais , Colorado , Resistência a Inseticidas , Fatores Sexuais , Fatores de Tempo
15.
PeerJ ; 6: e5354, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30065894

RESUMO

This contribution describes seven new species of fossil stoneflies from Cretaceous Burmese amber, all of which are dedicated to present and past members of the Rolling Stones. Two species-Petroperla mickjaggeri gen. nov. sp. nov. and Lapisperla keithrichardsi gen. nov. sp. nov.-are placed in a new family Petroperlidae within the stemline of Systellognatha. The first Cretaceous larval specimen of Acroneuriinae, Electroneuria ronwoodi gen. nov. sp. nov., is also described along with another four new species that are placed within the Acroneuriinae genus Largusoperla Chen et al., 2018: Largusoperla charliewattsi sp. nov., Largusoperla brianjonesi sp. nov., Largusoperla micktaylori sp. nov., and Largusoperla billwymani sp. nov. Additional specimens of Acroneuriinae are described without formal assignment to new species due to insufficient preservation. Implications for stonefly phylogeny and palaeobiogeography are discussed.

16.
Zookeys ; (774): 77-104, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30057465

RESUMO

Mayfly larvae and imagos were collected at approximately 50 localities of the Kingdom of Saudi Arabia (KSU). Included in this material, three species of Labiobaetis Novikova & Kluge, 1987 are recorded, two of them being new to science. Labiobaetis potamoticus Gattolliat & Al Dhafer, sp. n. is described from both larvae and adults, whereas Labiobaetis alahmadii Gattolliat & Al Dhafer, sp. n. is only known from the larval stage. The two species are compared morphologically with Palearctic and Afrotropical species of Labiobaetis. A third species, Labiobaetis glaucus (Agnew, 1961) is reported for the first time from the Arabian Peninsula. The species was originally described from South Africa and subsequently reported from the east and northeast of Africa. A molecular reconstruction including 18 Afrotropical and Palearctic species of Labiobaetis was performed using 658 bp of the mitochondrial gene CO1. The reconstruction highly supported the validity of the two new species and confirmed the occurrence of L. glaucus in KSU.

17.
Zookeys ; (653): 1-78, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28331393

RESUMO

This study was conducted as a part of a comprehensive baseline survey of insect biodiversity of Rawdhat Khorim National Park (RKNP), Central Kingdom of Saudi Arabia (KSA). During this study a total of 262 Coleoptera species belong to 182 genera in 35 families were identified, of which 247 are named at a species level. Fifteen species (6.0%) are apparently endemic to KSA. Thirty-eight species are new to the known beetle fauna of KSA, including 25 species reported from the Arabian Peninsula for the first time. The families Tenebrionidae (45 species), Scarabaeidae (34 species), and Carabidae (27 species) were the most species rich families. About 37% of the beetle abundance was represented by species of Scarabaeidae, especially Aphodius ictericus ghardimaouensis Balthasar. Karumia inaequalis Pic (Dascillidae) was also an abundant species. Approximately 43.5% of beetle species collected during this study are considered very rare taxa in RKNP. The RKNP beetle fauna shows more affinity to Sahro-Arabian (36.4%), Afrotropical-Sahro-Arabian (17.4%) and Palaearctic-Sahro-Arabian (10.5%). Twenty-three species (9.3%) are considered cosmopolitan or subcosmopolitan. The data on month of collection, method of collection, and abundance status within RKNP, together with the distribution within KSA and the general distribution (zoogeography) of each species are presented.

18.
Zootaxa ; 4247(1): 73-77, 2017 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-28610091

RESUMO

The Lepidoptera of North America Network, or LepNet, is a digitization effort recently launched to mobilize biodiversity data from 3 million specimens of butterflies and moths in United States natural history collections (http://www.lep-net.org/). LepNet was initially conceived as a North American effort but the project seeks collaborations with museums and other organizations worldwide. The overall goal is to transform Lepidoptera specimen data into readily available digital formats to foster global research in taxonomy, ecology and evolutionary biology.


Assuntos
Lepidópteros , Animais , Biodiversidade , Borboletas , Museus , América do Norte , Estados Unidos
19.
J Forensic Sci ; 51(5): 1164-5, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17018102

RESUMO

We report on the colonization of an adult human corpse by three insect species at 3350 m (11,000 ft) in elevation. The adult silphid Thanatophilus coloradensis (Wickham), adults of the blow fly Calliphora coloradensis (Hough), and larvae and adults of Lucilia silvarum (Meigen) were all collected from the victim's body which had been wrapped in plastic. The victim was found in late June in the Rocky Mountains of Colorado. This paper provides additional confirmation of the taxa utilizing a human corpse at high elevations in Colorado.


Assuntos
Altitude , Dípteros , Entomologia , Antropologia Forense , Adulto , Animais , Colorado , Humanos , Larva , Masculino
20.
Artigo em Inglês | MEDLINE | ID: mdl-27481793

RESUMO

DNA barcoding was intended as a means to provide species-level identifications through associating DNA sequences from unknown specimens to those from curated reference specimens. Although barcodes were not designed for phylogenetics, they can be beneficial to the completion of the Tree of Life. The barcode database for Trichoptera is relatively comprehensive, with data from every family, approximately two-thirds of the genera, and one-third of the described species. Most Trichoptera, as with most of life's species, have never been subjected to any formal phylogenetic analysis. Here, we present a phylogeny with over 16 000 unique haplotypes as a working hypothesis that can be updated as our estimates improve. We suggest a strategy of implementing constrained tree searches, which allow larger datasets to dictate the backbone phylogeny, while the barcode data fill out the tips of the tree. We also discuss how this phylogeny could be used to focus taxonomic attention on ambiguous species boundaries and hidden biodiversity. We suggest that systematists continue to differentiate between 'Barcode Index Numbers' (BINs) and 'species' that have been formally described. Each has utility, but they are not synonyms. We highlight examples of integrative taxonomy, using both barcodes and morphology for species description.This article is part of the themed issue 'From DNA barcodes to biomes'.


Assuntos
Código de Barras de DNA Taxonômico , Insetos/classificação , Filogenia , Animais , Biodiversidade , Haplótipos , Insetos/genética , Análise de Sequência de DNA
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA