Spring Populations Research Articles

The effect of landscape heterogeneity on population density and habitat preferences of the European hare (Lepus europaeus) in contrasting farmlands

We assessed the effect of habitat heterogeneity and predator density on the European hare (Lepus europaeus), a declining farmland specialist, in intensive farmlands in Central Europe. Using spotlight surveys we explored population density and habitat preference of the European hare in spring and autumn during 2014–2015 in seven farmland regions, of which six were located in the Czech Republic and one in Austria. The average population density of European hares significantly differed between study regions in the Czech Republic and Austria, however, we found no differences in population density between autumn and spring. In particular, the average European hare population density in study regions in the Czech Republic varied between 6.8–17.0 individuals/100ha, whereas in Austria the population density reached 65.3 individuals/100ha. Differences between spring and autumn population densities were not significant. European hare population density was significantly negatively affected by mean patch size and positively by area of arable land. We did not find a significant effect of red fox (Vulpes vulpes) presence on the numbers of European hares in individual regions. Habitat preferences differed among regions with contrasting population densities and field sizes, hares in regions of high density and small fields were more equally distributed among available habitats compared to regions of low or intermediate density and large fields. To conclude, conservation measures focusing on enhancing habitat heterogeneity by reducing field size may be an effective tool to support populations of European hares in arable farmland landscapes.

The transcriptomes of cave and surface populations of Gammarus minus (Crustacea: Amphipoda) provide evidence for positive selection on cave downregulated transcripts.

Gammarus minus, a freshwater amphipod living in the cave and surface streams in the eastern USA, is an excellent model for investigating evolutionary adaptation to the subterranean environment. RNA-Seq was conducted on one pair of morphologically distinct sister populations inhabiting surface and cave habitats to identify genes that were differentially expressed in the two populations, as well as to compare levels and patterns of genetic variation within and between populations. Of the 104,630 transcripts identified in the transcriptome assembly, 57% had higher average levels of expression in the cave population. After Benjamini-Hochberg correction for multiple tests, 1517 and 551 transcripts were significantly upregulated or downregulated, respectively, in the cave population, indicating an almost three-fold enrichment of cave-upregulated genes. The average level of nucleotide diversity across all transcripts was significantly lower in the cave population. Within the cave population, where the average nucleotide diversity of cave-downregulated transcripts was 75% that of the cave-upregulated transcripts, a highly significant difference, whereas within the spring population the nucleotide diversities of cave-downregulated and cave-upregulated transcripts was virtually identical. Three lines of evidence suggest that the reduced variation in cave downregulated transcripts is due to positive selection in the cave population: 1) the average neutrality index of cave-downregulated genes was < 1, consistent with positive selection, and significantly less than that of cave-upregulated genes; 2) Tajima’s D was positively correlated with the cave:surface expression ratio, and 3) cave-downregulated transcripts were significantly more likely to be highly diverged from their surface homologs than cave-upregulated transcripts. Five transcripts had fixed premature termination codons in the cave population. The expression patterns and sequence variation in one such transcript, encoding the DNA repair protein photolyase, were examined in more detail and provide the first evidence for the relaxation of functional constraint in this light-dependent protein in a subterranean population.

Factors affecting the bacterial community composition and heterotrophic production of Columbia River estuarine turbidity maxima.

Estuarine turbidity maxima (ETM) function as hotspots of microbial activity and diversity in estuaries, yet, little is known about the temporal and spatial variability in ETM bacterial community composition. To determine which environmental factors affect ETM bacterial populations in the Columbia River estuary, we analyzed ETM bacterial community composition (Sanger sequencing and amplicon pyrosequencing of 16S rRNA gene) and bulk heterotrophic production (3H‐leucine incorporation rates). We collected water 20 times to cover five ETM events and obtained 42 samples characterized by different salinities, turbidities, seasons, coastal regimes (upwelling vs. downwelling), locations, and particle size. Spring and summer populations were distinct. All May samples had similar bacterial community composition despite having different salinities (1–24 PSU), but summer non‐ETM bacteria separated into marine, freshwater, and brackish assemblages. Summer ETM bacterial communities varied depending on coastal upwelling or downwelling conditions and on the sampling site location with respect to tidal intrusion during the previous neap tide. In contrast to ETM, whole (>0.2 μm) and free‐living (0.2–3 μm) assemblages of non‐ETM waters were similar to each other, indicating that particle‐attached (>3 μm) non‐ETM bacteria do not develop a distinct community. Brackish water type (ETM or non‐ETM) is thus a major factor affecting particle‐attached bacterial communities. Heterotrophic production was higher in particle‐attached than free‐living fractions in all brackish waters collected throughout the water column during the rise to decline of turbidity through an ETM event (i.e., ETM‐impacted waters). However, free‐living communities showed higher productivity prior to or after an ETM event (i.e., non‐ETM‐impacted waters). This study has thus found that Columbia River ETM bacterial communities vary based on seasons, salinity, sampling location, and particle size, with the existence of three particle types characterized by different bacterial communities in ETM, ETM‐impacted, and non‐ETM‐impacted brackish waters. Taxonomic analysis suggests that ETM key biological function is to remineralize organic matter.

An integrated modeling approach for assessing management objectives for mule deer in central British Columbia

ABSTRACTWe used an integrated Bayesian state‐space population model to assess whether management objectives were met before (1995–2003), during (2004–2010), and after (2011–2013) antlerless permits to harvest mule deer (Odocoileus hemionus) were increased in response to stakeholder concerns in central British Columbia, Canada. Data inputs included 19 years of harvest data, 7 years of autumn age–sex composition data, 17 years of spring age–sex composition data, and 15 years of a population index. Management objectives were to maintain a spring population of 7,000–9,000 deer and a posthunt adult sex ratio of 20–30 males:100 females. An 8.5‐fold increase in antlerless permits raised the antlerless harvest rates from 1.0% (1995–2003) to 4.8% (2004–2010). Antlerless harvest rates decreased to 2.8% following a 53% decrease in permits from 2011 to 2013. Population projections from 2014 to 2018 fell within the bounds of the management objectives, but 95% credibility intervals revealed great uncertainty in population size and composition. We recommend a structured, adaptive approach to mule deer management that includes annual adjustment of harvests, monitoring, and modeling, with an open‐ended stakeholder engagement process to ensure objectives remain relevant, measurable, and achievable. © 2017 The Wildlife Society.

ENDOPOLYPLOIDY OF ENDANGERED PLANT SPECIES LIGULARIA SIBIRICA IN DIFFERENT ENVIRONMENTS

The goal of this study was to detect endopolyploidy of Ligularia sibirica from populations existed in different ecological conditions. This is important step to elaborate the appropriate protection measures of rare and endangered species, which should be based on understanding of ongoing processes in populations. From this point of view the knowledge of genetic diversity, including endopolyploidy level between and within populations, is crucial. L. sibirica is endangered and protected plant species in Latvia which is included in the protected plants list of EU Habitat directive 92/43/EEK Annexes 2 and 4. Perennial herbaceous plant L. sibirica is one of two species of genus Ligularia in Europe. According to the previous data, this species has been disappeared from all previously known locations in Latvia. However, some new locations were found in central part of the country recently. Determination of edopolyploidy level of L. sibirica was performed by the BD FACSJazz® cell sorter (BD Biosciences, USA) with flow cytometer function. In young leafs nine relative fluorescence DNA peaks from 2C up to 64 C were detected. The most common was 2C peak presented in 93% and 63% of samples from Zušu-Staiņu sulphur spring and Krustkalni Nature reserve populations respectively.

Sulfolobus islandicus meta-populations in Yellowstone National Park hot springs.

Abiotic and biotic forces shape the structure and evolution of microbial populations. We investigated forces that shape the spatial and temporal population structure of Sulfolobus islandicus by comparing geochemical and molecular analysis from seven hot springs in five regions sampled over 3 years in Yellowstone National Park. Through deep amplicon sequencing, we uncovered 148 unique alleles at two loci whose relative frequency provides clear evidence for independent populations in different hot springs. Although geography controls regional geochemical composition and population differentiation, temporal changes in population were not explained by corresponding variation in geochemistry. The data suggest that the influence of extinction, bottleneck events and/or selective sweeps within a spring and low migration between springs shape these populations. We suggest that hydrologic events such as storm events and surface snowmelt runoff destabilize smaller hot spring environments with smaller populations and result in high variation in the S. islandicus population over time. Therefore, physical abiotic features such as hot spring size and position in the landscape are important factors shaping the stability and diversity of the S. islandicus meta-population within Yellowstone National Park.

Epizootic and Epidemiological Situation of Trichinella sp. Infection in Poland in 2006-2015 in View of Wild Boar Population Dynamics.

IntroductionThe objective was to evaluate the epizootic and epidemiological situation of Trichinella sp. infection in Poland between 2006 and 2015 against the dynamics of the wild boar population and its primary reservoir host.Material and MethodsBoar and porcine trichinosis epizootic analysis was based on General Veterinary Inspectorate data from RRW-6 bulletins. The epidemiological situation was evaluated on the basis of the data supplied by the Department of Epidemiology of the National Institute of Hygiene - National Institute of Public Health. The wild boar hunting harvest and population dynamics were estimated, as these animals remain the basic infection source for humans. Population size and harvest data were obtained from hunting statistics.ResultsThe study timeframe showed an almost 2.5-fold increase in Trichinella infection cases in wild boars but a significant decline in human cases. In the domestic pig, the incidence rate did not exceed 0.00037%. The highest infection risk exists in West Pomerania, Greater Poland, and Kuyavian-Pomeranian Provinces. Over the study period, the wild boar population increased more than 1.5-fold, while the hunting harvest more than tripled. During the last two seasons the total hunt surpassed 100% of the spring population.ConclusionWild boar management by increasing the hunting take of the annual population growth should limit that growth and decrease the take in the future. Thereby, over some years intra-species trichinosis spread should reduce, for a substantial safety gain for wild boar meat.

Characterization and phylogenetic analysis of complete mitochondrial genomes for two desert cyprinodontoid fishes, Empetrichthys latos and Crenichthys baileyi

The Pahrump poolfish (Empetrichthys latos) and White River springfish (Crenichthys baileyi) are small-bodied teleost fishes (order Cyprinodontiformes) endemic to the arid Great Basin and Mojave Desert regions of western North America. These taxa survive as small, isolated populations in remote streams and springs and evolved to tolerate extreme conditions of high temperature and low dissolved oxygen. Both species have experienced severe population declines over the last 50–60years that led to some subspecies being categorized with protected status under the U.S. Endangered Species Act. Here we report the first sequencing of the complete mitochondrial DNA genomes for both E. l. latos and the moapae subspecies of C. baileyi. Complete mitogenomes of 16,546bp nucleotides were obtained from two E. l. latos individuals collected from introduced populations at Spring Mountain Ranch State Park and Shoshone Ponds Natural Area, Nevada, USA, while a single mitogenome of 16,537bp was sequenced for C. b. moapae. The mitogenomes of both species contain 13 protein-encoding genes, twenty-two tRNAs, and two rRNAs (12S and 18S) following the syntenic arrangement typical of Actinopterygiian fish mitogenomes, as well as D-loop control regions of 858bp for E. latos and 842bp for C. baileyi moapae. The two E. latos individuals exhibited only 0.0181% nucleotide sequence divergence across the entire mitogenome, implying little intraspecific mtDNA genetic variation. Comparative phylogenetic analysis of the poolfish and springfish mitochondrial genomes to available mitogenomes of other Cyprinodontoid fishes confirmed the close relationship of these oviparous Empetrichthys and Crenichthys genera to the viviparous goodeid fishes of central Mexico, and showed the combined clade of these fishes to be a sister group to the Profundulidae killifishes. Despite several significant life history and morphological differences between the Empetrichthyinae and Goodienae, estimates of evolutionary genetic distances using two partial regions of mtDNA point to inclusion of the Empetrichthys and Crenichthys genera within the family Goodeidae along with the goodeid fishes of central Mexico.

Genetic signatures of translocations and habitat fragmentation for two evolutionarily significant units of a protected fish species

Genetic population structure was evaluated for the White Sands pupfish (Cyprinodon tularosa), a protected fish species comprised of two Evolutionarily Significant Units (ESUs); the Malpais Spring ESU and the Salt Creek ESU. The Malpais Spring ESU is restricted to Malpais Spring, whereas the Salt Creek ESU includes the native Salt Creek population and two Salt Creek-derived populations at Mound Spring and Lost River; all three of these habitats are physically fragmented. We sampled the upper and lower reaches of the four populations, examining 13 DNA microsatellite loci from 40 individuals per population. As expected, significant genetic structure was observed between the two ESUs; Malpais Spring and Salt Creek. Substantial genetic drift was observed for the introduced Lost River population, with modest genetic drift for the introduced Mound Spring population. Taken together with ecological data, neither of the introduced populations successfully replicates the Salt Creek population. We also report significant reductions in genetic diversity for the upper reaches of both Salt Creek and Lost River, indicating that recent habitat changes have altered the genetic structure of these two populations. We consider these findings along with previously reported ecological data to develop guidelines for managing C. tularosa.

A missing source of aerosols in Antarctica – beyond long-range transport, phytoplankton, and photochemistry

Abstract. Understanding the sources and evolution of aerosols is crucial for constraining the impacts that aerosols have on a global scale. An unanswered question in atmospheric science is the source and evolution of the Antarctic aerosol population. Previous work over the continent has primarily utilized low temporal resolution aerosol filters to answer questions about the chemical composition of Antarctic aerosols. Bulk aerosol sampling has been useful in identifying seasonal cycles in the aerosol populations, especially in populations that have been attributed to Southern Ocean phytoplankton emissions. However, real-time, high-resolution chemical composition data are necessary to identify the mechanisms and exact timing of changes in the Antarctic aerosol. The recent 2ODIAC (2-Season Ozone Depletion and Interaction with Aerosols Campaign) field campaign saw the first ever deployment of a real-time, high-resolution aerosol mass spectrometer (SP-AMS – soot particle aerosol mass spectrometer – or AMS) to the continent. Data obtained from the AMS, and a suite of other aerosol, gas-phase, and meteorological instruments, are presented here. In particular, this paper focuses on the aerosol population over coastal Antarctica and the evolution of that population in austral spring. Results indicate that there exists a sulfate mode in Antarctica that is externally mixed with a mass mode vacuum aerodynamic diameter of 250 nm. Springtime increases in sulfate aerosol are observed and attributed to biogenic sources, in agreement with previous research identifying phytoplankton activity as the source of the aerosol. Furthermore, the total Antarctic aerosol population is shown to undergo three distinct phases during the winter to summer transition. The first phase is dominated by highly aged sulfate particles comprising the majority of the aerosol mass at low wind speed. The second phase, previously unidentified, is the generation of a sub-250 nm aerosol population of unknown composition. The second phase appears as a transitional phase during the extended polar sunrise. The third phase is marked by an increased importance of biogenically derived sulfate to the total aerosol population (photolysis of dimethyl sulfate and methanesulfonic acid (DMS and MSA)). The increased importance of MSA is identified both through the direct, real-time measurement of aerosol MSA and through the use of positive matrix factorization on the sulfur-containing ions in the high-resolution mass-spectral data. Given the importance of sub-250 nm particles, the aforementioned second phase suggests that early austral spring is the season where new particle formation mechanisms are likely to have the largest contribution to the aerosol population in Antarctica.

How Many Are There? Estimating the North American Northern Bobwhite Population Size for Conservation Planning Purposes

Three bird habitat Joint Ventures, Gulf Coast, Oaks & Prairies, and Rio Grande, developed a method to set spring population and habitat objectives for northern bobwhite (Colinus virginianus) populations in four Bird Conservation Regions (BCRs). The method requires an estimate of current population size that can be stepped down to the management unit of interest. Several methods have been designed to estimate range-wide populations over the past two decades for fall (post-breeding) and spring (pre-breeding). The 2002 Northern Bobwhite Conservation Initiative (NBCI) provided an estimate of 6,714,000 birds for the 1999 breeding population. The 2007 Partners in Flight (PIF) Population Estimates database provided a spring population estimate of 7,600,000 based on Breeding Bird Survey (BBS) densities. The NBCI 2011 revision population estimate, using BCR-specific Estimated Densities and habitat acreages, summed to greater than 26,000,000 individuals for fall population. The current PIF (2013) Population Estimates database includes 5,800,000 individuals as a global (spring) population estimate, and cites the NBCI. This estimate may result from application of the range-wide BBS trend estimate from 1982-1999 (3.8%) to the 2002 NBCI spring estimate. This produces a 2003 population estimate of ~5,800,000, which may have been substituted for the BBS-based estimate used in the 2004 PIF North American Landbird Conservation Plan. Finally, a recent unpublished estimate based upon the BBS-based PIF calculated estimate suggests a population of almost 18,000,000 in the U.S. and Canada. This value excludes birds in Mexico, estimated to comprise approximately 15.6% of the global population. We compared PIF estimates with the 2011 NBCI estimate. While there is some correlation regarding population density estimates at the BCR level, there is considerable disparity between overall population estimates between the two documents. The bird conservation community would benefit from an examination of northern bobwhite population estimates, to improve accuracy of spring population and habitat objectives.

闽东北海域假长缝拟对虾种群分布格局强度

PDF HTML阅读 XML下载 导出引用 引用提醒 闽东北海域假长缝拟对虾种群分布格局强度 DOI: 10.5846/stxb201605180959 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 福建省科技厅省属公益类科研院所基本科研专项（2012R1101-1，2015R1003-2）；福建省科技创新平台建设项目（2015N2001）；闽台重要海洋生物资源高值化开发技术公共服务平台项目（2014FJPT01）；福建重要海洋经济生物种质库与资源高效开发技术公共服务平台项目（14PZY017NF17） Pattern intensity of Parapenaeus fissuroides Crosnier in sea area in the northeast of Fujian Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以负二项参数、Mrisita指数、平均拥挤度、聚块指数和扩散系数为种群分布格局强度指标，分析了闽东北海域假长缝拟对虾（Parapenaeus fissuroides Crosnier）种群分布格局强度，探讨了种群分布格局强度生态学意义及其影响因子。结果显示：假长缝拟对虾种群聚集强度和聚块性夏季最强，其余依次为秋季、春季和冬季，平均拥挤度夏季最大，其次是秋季、冬季，春季最小，扩散程度春季最大，其次是冬季、秋季，夏季最小。负二项参数和Mrisita指数表征种群聚集强度，聚块指数体现种群斑块的组成形式，个体平均拥挤度指数反映平均个体实际的拥挤程度，扩散系数反映种群扩散程度。饵料浮游动物是影响假长缝拟对虾种群聚集强度的主要因子，种内竞争是影响假长缝拟对虾种群扩散程度的主要因子。 Abstract:In the current study, we analyzed the aggregation pattern of Parapenaeus fissuroides Crosnier in sea area in the northeast of Fujian based on pattern intensity index of the negative binomial parameter, Morisita index, mean crowding, poly block index, and diffusion coefficient. We also discuss the factors that affect pattern intensity and ecological significance of the pattern intensity indices. The aim of the study was to explore new aspects in the protection of the fishery resources for P. fissuroides Crosnier. In spring, its population primarily consisted of twelve patches, which showed dispersed population distribution and the second smallest poly block index. The population in spring had the smallest mean crowding, the largest average distance between individuals, and the biggest diffusion coefficient compared to that in other seasons. In summer, the population mainly consisted of four patches with most concentrated population distribution. The biggest poly block index, biggest mean crowding, smallest average distance between individuals, and smallest diffusion coefficient were observed. In autumn, the population primarily consisted of five patches with moderately concentrated population distribution. The second largest poly block index and mean crowding as well as the second smallest average distance between the individual diffusion coefficient were explored. In winter, the population primarily consisted of fourteen patches with highly dispersed population distribution, the smallest poly block index, the second smallest mean crowding, and the second largest average distance between individuals and diffusion coefficient. The negative binomial parameter and Morisita index were employed to characterize the aggregation intensity. When the Morisita index is greater and the negative binomial parameter is smaller, the aggregation intensity is stronger, and vice versa. Mean crowding provided a more actual representation of the average individual crowding degree compared with the average density. Mean crowding reflected the average individual crowded degree. When mean crowding was large, the inter-specific competition was intense,and average distance between individuals was smallest. The poly block index revealed the constitution of the population patches. When the poly block index was big, the population primarily consisted of a few patches, and vice versa. The diffusion coefficient reflected the diffusion degree. The bigger the diffusion coefficient, the greater was the significant spread of the population. The food zooplankton was the major factor influencing the pattern intensity, and the inter-specific competition was the major factor mediating diffusion degree of the Parapenaeus fissuroides Crosnier in the sea area northeast of Fujian. In this study, the population distribution pattern intensity simplified the research of school behavior, which reflect the aggregation intensity, poly block, mean crowding, inter-specific competition degree, and diffusion degree to meet the school behavior inherent law. 参考文献 相似文献 引证文献

A Method for Setting Northern Bobwhite Population and Habitat Objectives for Large Landscape Partnerships

Population and habitat objectives are the foundation for many conservation actions. Often objectives set at one scale are difficult to translate to larger or smaller scales. Three bird habitat Joint Ventures, Gulf Coast, Oaks & Prairies, and Rio Grande, working cooperatively with the Gulf Coast Prairie Landscape Conservation Cooperative, have a common objective to stabilize northern bobwhite (Colinus virginianus) populations in four Bird Conservation Regions. We cooperatively developed a method using the North American Breeding Bird Survey trend for several scenarios with different time horizons (10-, 20-, 30-year, or longer), the spring home range size, and the per acre cost of habitat management actions, to set spring population and habitat objectives and projected costs. The spring population objectives can easily be converted to fall population objectives using the percent summer gain. We provide an example of how three Joint Ventures could use this methodology to set bobwhite objectives within their geographies and then scale those objectives up to the next larger geography, a Landscape Conservation Cooperative geography. This methodology can be used by other multi-state partnerships (e.g., Joint Ventures and Landscape Conservation Cooperatives) across the bobwhite range to provide the bobwhite conservation community meaningful objectives at regional and national scales.

Ecology of ontogenetic body-mass scaling of gill surface area in a freshwater crustacean

Several studies have documented ecological effects on intraspecific and interspecific body-size scaling of metabolic rate. However, little is known about how various ecological factors may affect the scaling of respiratory structures supporting oxygen uptake for metabolism. To our knowledge, our study is the first to provide evidence for ecological effects on the scaling of a respiratory structure among conspecific populations of any animal. We compared the body-mass scaling of gill surface area (SA) among eight spring-dwelling populations of the amphipod crustacean Gammarus minus Although gill SA scaling was not related to water temperature, conductivity or G. minus population density, it was significantly related to predation regime (and secondarily to pH). Body-mass scaling slopes for gill SA were significantly lower in four populations inhabiting springs with fish predators than for four populations in springs without fish (based on comparing means of the population slopes, or slopes calculated from pooled raw data for each comparison group). As a result, gill SA was proportionately smaller in adult amphipods from springs with versus without fish. This scaling difference paralleled similar differences in the scaling exponents for the rates of growth and resting metabolic rate. We hypothesized that gill SA scaling is shallower in fish-containing versus fishless spring populations of G. minus because of effects of size-selective predation on size-specific growth and activity that in turn affect the scaling of oxygen demand and concomitantly the gill capacity (SA) for oxygen uptake. Although influential theory claims that metabolic scaling is constrained by internal body design, our study builds on previous work to show that the scaling of both metabolism and the respiratory structures supporting it may be ecologically sensitive and evolutionarily malleable.

Field Application of Sustained-Yield Harvest Management for Northern Bobwhite in Texas

Sustained-yield harvest (SYH) is considered a potentially viable strategy for managing harvest of northern bobwhites (Colinus virginianus). However, application of SYH has not been evaluated for northern bobwhites. We evaluated the application of using SYH as a harvest management strategy for bobwhite during the 2007 2008 and 2008 2009 hunting seasons in 2 ecoregions of Texas (Rolling Plains, South Texas Plains). We collected field data at 3 study sites/ecoregion (900 1,900 ha each; 2 hunted sites and 1 control) to estimate 4 demographic parameters (fall and spring density, overwinter survival in the absence of hunting, and harvest rate). We used these data to parameterize the additive harvest model for bobwhites and compare predictions of spring abundance of the model with field estimates. The additive harvest model, compared to field estimates, consistently underestimated spring population density (mean 6 SE) by 55.7 6 17.8% (2007 2008) and 34.1 6 4.9% (2008 2009) in the Rolling Plains, and by 26.4 6 25.3% (2007 2008) and 49.1 6 2.1% (2008 2009) in the South Texas Plains. Implementing SYH in the field, despite its potential benefits, will be challenging given the need for reliable estimates of 3 key population parameters (fall and spring density, and natural mortality in the absence of hunting) and the high variation often associated with them. Conservative harvest prescriptions based on the lower 95% CIs of fall density estimates may permit sustainable harvest despite variation in density estimates.

Prolonged coldness on eggs reduces immature survival and reproductive fitness in Tetranychus urticae (Acari: Tetranychidae)

Tetranychus urticae Koch (Arachnida: Acari: Tetranychidae) is an economically important agricultural and horticultural pest around the world. The present study investigated the prolonged exposure of eggs (i.e., 0, 24, 48, 72, and 96 hours) to low temperature (i.e., 5 ºC) affecting the egg hatching, and subsequent immature development and survival as well as the reproductive fitness of resultant females. Our results show that chilling had no significant effect on egg hatching rate, but significantly shortened egg development. It was found that prolonged chilling significantly decreased the survival of immature stages. Prolonged chilling also significantly delayed the development of males and thus adult emergence, but had not significantly effect on female development and survival. Results further indicate that the negative effect of lengthy chilling extended to the resultant females resulting in the significantly shorter longevity and lower fecundity. It is interesting that the resultant females might benefit from parental egg chilling, i.e., they started oviposition significantly early and produced significantly higher female-biased sex ratio. The implications from the results of this study in forecasting spring populations and outbreak of this pest in the growing season were discussed.

Transcriptomic profiles of spring and summer populations of the Southern Ocean salp, Salpa thompsoni, in the Western Antarctic Peninsula region

The Southern Ocean salp, Salpa thompsoni (Tunicata, Thaliacea), is a pivotal species in the pelagic ecosystem of the Western Antarctic Peninsula (WAP), one of the fastest warming regions of the world oceans. This study produced a complete reference transcriptome for S. thompsoni containing 216,931 sequences; 41,210 (18%) were associated with predicted, hypothetical, or known proteins; 13,058 (6%) were mapped and annotated. Whole-transcriptome (RNA-seq) analysis of 39 samples collected during austral spring and summer 2011 in the WAP and in summer 2009 in the Indian Sector revealed clustering of samples by regions, seasons, and areas (Bray–Curtis similarity). The highest numbers of differentially expressed genes at the 4×, 20×, and 100× fold-change levels were found between salps collected during spring versus summer 2011 in the WAP (analysis of variance, ANOVA). Spring versus summer samples showed significant differential expression of 77 genes associated with environmental stress response and 51 genes associated with sexual reproduction (paired t tests, p < 0.05), with significant association between expression of these genes and temperature at the collection site shown by multidimensional scaling analysis. Gene Ontology (GO) term enrichment analysis identified 41 GO terms responsible for spring versus summer differences, including 156 genes associated with translation (i.e., protein synthesis). The reference transcriptome and characterization of time/space patterns of whole-transcriptome and target gene differential expression provide a foundation for functional analysis and identification of molecular markers of physiological condition, life history events, and responses to climate change in this key species in Antarctic pelagic ecosystems.

Багаторічна динаміка щільності стану розвитку міжвидових популяцій злакових попелиць (Homoptera, Aphididae) упродовж вегетації пшениці озимої в умовах Лісостепу України

Багаторічна динаміка щільності стану розвитку міжвидових популяцій злакових попелиць (Homoptera, Aphididae) упродовж вегетації пшениці озимої в умовах Лісостепу України

Report on the life history traits of the generalist predatorForficula auricularia(Dermaptera: Forficulidae) in organic apple orchards in southeastern France

AbstractThe aim of this paper is to provide detailed data on the reproduction of the European earwigForficula auriculariaLinnaeus (Dermaptera: Forficulidae) under natural conditions. We also describe its spring field population structure and dynamics in organic apple orchards in southeastern France using artificial and natural shelters. Two nymph cohorts could be distinguished in a laboratory reproduction study. The first brood, following the first egg-laying event in late November, had significantly higher pre-imaginal survival (1.74-fold) than the second brood in early April. The egg phase was the most vulnerable with a higher mortality rate in the first brood than the second. Independent of brood number, nymphal survival increased from second nymphal instars (N2) onwards with values higher than 96%. In orchards, N3 were generally observed in natural and artificial shelters from the end of April to mid-June. N4 was the most abundant life stage sampled and the only stage present at the majority of sampling dates, especially from early May onwards. Beginning in June, the abundance of new adults of a given year gradually increased especially in the artificial shelters. This descriptive study can now be used to develop phenological models aimed at limiting earwig mortality due to horticultural management practices and increasing their predation level in conservative or augmentative approaches.

Efficacy of Five Insecticides Targeting Spring and Fall Populations of Sugarcane Beetle Adults

Summary Sugarcane beetle (Euetheola rugiceps LeConte; Coleoptera: Scarabaeidae) is a pest of turfgrass in the southeastern United States. This study was conducted to evaluate the toxicity of 5 products for sugarcane beetle pest management in managed bermudagrass (Cynodon dactylon L.; Poaceae). Spring and fall populations of sugarcane beetle adults were exposed to 4 active ingredients and combinations (bifenthrin, bifenthrin plus clothianidin, carbaryl, clothianidin, and dinotefuran) under greenhouse conditions. At 7 d after treatment, there were no significant differences among insecticide treatments applied to spring beetles at either a low or a high field rate, although all insecticides caused a significant increase in beetle mortality relative to untreated (control) beetles. In contrast, bifenthrin caused significantly greater control of fall populations at the low field rate compared with other treatments. Target population (spring or fall) appears to have more impact on pesticide efficacy than either...