bluuebunny/crossref_metadata_2025_split huggingface dataset:
The biogeography of prediction error: why does the introduced range of the fire ant over‐predict its native range?
Authors: Fitzpatrick Matthew C. , Weltzin Jake F. , Sanders Nathan J. , Dunn Robert R. 
Published: December 2006

ABSTRACTAim  The use of species distribution models (SDMs) to predict biological invasions is a rapidly developing area of ecology. However, most studies investigating SDMs typically ignore prediction errors and instead focus on regions where native distributions correctly predict invaded ranges. We investigated the ecological significance of prediction errors using reciprocal comparisons between the predicted invaded and native range of the red imported fire ant (Solenopsis invicta) (hereafter called the fire ant). We questioned whether fire ants occupy similar environments in their native and introduced range, how the environments that fire ants occupy in their introduced range changed through time relative to their native range, and where fire ant propagules are likely to have originated.Location  We developed models for South America and the conterminous United States (US) of America.Methods  We developed models using the Genetic Algorithm for Rule‐set Prediction (GARP) and 12 environmental layers. Occurrence data from the native range in South America were used to predict the introduced range in the US and vice versa. Further, time‐series data recording the invasion of fire ants in the US were used to predict the native range.Results  Native range occurrences under‐predicted the invasive potential of fire ants, whereas occurrence data from the US over‐predicted the southern boundary of the native range. Secondly, introduced fire ants initially established in environments similar to those in their native range, but subsequently invaded harsher environments. Time‐series data suggest that fire ant propagules originated near the southern limit of their native range.Conclusions  Our findings suggest that fire ants from a peripheral native population established in an environment similar to their native environment, and then ultimately expanded into environments in which they are not found in their native range. We argue that reciprocal comparisons between predicted native and invaded ranges will facilitate a better understanding of the biogeography of invasive and native species and of the role of SDMs in predicting future distributions.
Differential effects of past climate warming on mountain and flatland species distributions: a multispecies North American mammal assessment
Authors: Guralnick Robert 
Published: December 2006

ABSTRACTAim The magnitude of predicted range shifts during climate change is likely to be different for species living in mountainous environments compared with those living in flatland environments. The southern edges of ranges in mountain species may not shift northwards during warming as populations instead migrate up available elevational gradients; overall latitudinal range appears therefore to expand. In contrast, flatland species should shift range centroids northwards but not expand or contract their latitudinal range extent. These hypotheses were tested utilizing Late Pleistocene and modern occurrence data.Location North America.Methods The location and elevation of modern and Late Pleistocene species occurrences were collected from data bases for 26 species living in mountain or flatland environments. Regressions of elevation change over latitude, and southern and northern range edges were calculated for each species for modern and fossil data sets. A combination of regressions andanovas were used to test whether flatland species shift range edges and latitudinal extents more than mountain species do.Results Flatland species had significantly larger northward shifts at southern range edges than did mountain‐dwelling species from the Late Pleistocene to the present. There was also a significant negative correlation between the amount of change in the latitude of the southern edge of the range and the amount of elevational shifting from the Late Pleistocene to the present. Although significant, onlyc. 25% of the variance could be explained by this relationship. In addition, there was a weak indication that overall range expansion was less in flatland‐dwelling than in mountain‐dwelling species.Main conclusions The approach used here was to examine past species’ range responses to warming that occurred after the last ice ages as a means to better predict potential future responses to continued warming. The results confirm predictions of differential southern edge and overall range shifts for species occupying mountain and flatland regions in North America. The findings may be broadly applicable in other regions, thus allowing better modelling of future range and distribution related responses.
The role of land cover in bioclimatic models depends on spatial resolution
Authors: Luoto Miska , Virkkala Raimo , Heikkinen Risto K. 
Published: December 2006

ABSTRACTAim  We explored the importance of climate and land cover in bird species distribution models on multiple spatial scales. In particular, we tested whether the integration of land cover data improves the performance of pure bioclimatic models.Location  Finland, northern Europe.Methods  The data of the bird atlas survey carried out in 1986–89 using a 10 × 10 km uniform grid system in Finland were employed in the analyses. Land cover and climatic variables were compiled using the same grid system. The dependent and explanatory variables were resampled to 20‐km, 40‐km and 80‐km resolutions. Generalized additive models (GAM) were constructed for each of the 88 land bird species studied in order to estimate the probability of occurrence as a function of (1) climate and (2) climate and land cover variables. Model accuracy was measured by a cross‐validation approach using the area under the curve (AUC) of a receiver operating characteristic (ROC) plot.Results  In general, the accuracies of the 88 bird–climate models were good at all studied resolutions. However, the inclusion of land cover increased the performance of 79 and 78 of the 88 bioclimatic models at 10‐km and 20‐km resolutions, respectively. There was no significant improvement at the 40‐km resolution. In contrast to the finer resolutions, the inclusion of land cover variables decreased the modelling accuracy at 80km resolution.Main conclusions  Our results suggest that the determinants of bird species distributions are hierarchically structured: climatic variables are large‐scale determinants, followed by land cover at finer resolutions. The majority of the land bird species in Finland are rather clearly correlated with climate, and bioclimate envelope models can provide useful tools for identifying the relationships between these species and the environment at resolutions ranging from 10 km to 80 km. However, the notable contribution of land cover to the accuracy of bioclimatic models at 10–20‐km resolutions indicates that the integration of climate and land cover information can improve our understanding and model predictions of biogeographical patterns under global change.
Patterns in species richness and endemism of European freshwater fish
Authors: Reyjol Yorick , Hugueny Bernard , Pont Didier , Bianco Pier Giorgio , Beier Ulrika , Caiola Nuño , Casals Frederic , Cowx Ian , Economou Alcibiades , Ferreira Teresa , Haidvogl Gertrud , Noble Richard , De Sostoa Adolfo , Vigneron Thibault , Virbickas Tomas 
Published: December 2006

ABSTRACTAim  To analyse the patterns in species richness and endemism of the native European riverine fish fauna, in the light of the Messinian salinity crisis and the Last Glacial Maximum (LGM).Location  European continent.Methods  After gathering native fish faunistic lists of 406 hydrographical networks, we defined large biogeographical regions with homogenous fish fauna, based on a hierarchical cluster analysis. Then we analysed and compared the patterns in species richness and endemism among these regions, as well as species–area relationships.Results  Among the 233 native species present in the data set, the Cyprinidae family was strongly dominant (> 50% of the total number of species). Seven biogeographical regions were defined: Western Peri‐Mediterranea, Central Peri‐Mediterranea, Eastern Peri‐Mediterranea, Ponto‐Caspian Europe, Northern Europe, Central Europe and Western Europe. The highest regional species richness was observed for Central Peri‐Mediterranea and Ponto‐Caspian Europe. The highest endemic richness was found in Central Peri‐Mediterranea. Species–area relationships were characterized by high slope values for Peri‐Mediterranean Europe and low values for Central and Western Europe.Main conclusions  The results were in agreement with the ‘Lago Mare’ hypothesis explaining the specificity of Peri‐Mediterranean fish fauna, as well as with the history of recolonization of Central and Western Europe from Ponto‐Caspian Europe following the LGM. The results also agreed with the mechanisms of speciation and extinction influencing fish diversity in hydrographical networks. We advise the use of the seven biogeographical regions for further studies, and suggest considering Peri‐Mediterranean Europe and Ponto‐Caspian Europe as ‘biodiversity hotspots’ for European riverine fish.
Does versatility as measured by geographic range, bathymetric range and morphological variability contribute to taxon longevity?
Authors: Liow Lee Hsiang 
Published: December 2006

ABSTRACTAim  This paper aims to examine the relationship between versatility as measured by geographic range, bathymetric range and morphological variability (species and subspecies richness and the occurrence of morphologically highly variable populations), and the geologic longevities of trachyleberidid ostracode species and genera, while accounting for sampling biases and other confounding factors.Location  Global.Methods  A large database of occurrence records of species of the family Trachyleberididae s.l. was analysed. The relationships between genus and species longevity and the above mentioned variables were examined singly and in concert. Re‐analyses of subsets of data and rarefaction techniques were employed to account for sampling biases, while randomization was used to account for autocorrelation of variables.Results  The mean number of occurrence records, and latitudinal and longitudinal ranges, were strongly and positively correlated with genus and species longevities. The number of bathymetric zones occupied by genera had no consistent bearing on their longevities, but species data subsets tended to indicate significant positive relationships between bathymetric range and longevities. Species richness was significantly and positively correlated with genus longevities. Species and genera with subspecies and species with high morphological variability all had significantly greater longevities. Genus‐level characteristics can be explained largely by species‐level characteristics, including longevity, latitudinal ranges and bathymetric ranges to a lesser degree. However, genus longevity was best explained by species richness and genus age, even for extinct genera, while species longevity was best explained by species latitudinal range.Main conclusions  In spite of the incompleteness of the fossil record, we can control for biasing factors and still confidently draw the conclusion that both ecological and evolutionary versatility contribute to lineage longevity, beyond the shorter temporal observation windows available to most ecological studies.
Plant odours with potential for a push–pull strategy to control the onion thrips, Thrips tabaci
Authors: Van Tol Rob W. H. M. , James Dale E. , De Kogel Willem Jan , Teulon David A. J. 
Published: December 2006

AbstractWe compared the efficacy of four plant essential oils to repel onion thrips, Thrips tabaci (Lindeman) (Thysanoptera: Thripidae), in the presence of an attractive odour, ethyl iso‐nicotinate in a pasture field. Four horizontal white sticky plates were placed adjacent to (directions: N, S, E, W) a central horizontal white plate (C). After 24 h, in the treatment combination where the four plates were sprayed with essential oil surrounding a central sticky plate sprayed with ethyl iso‐nicotinate, fewer onion thrips were found on the plates treated with sweet marjoram [Origanum majorana L. (Labiatae)] or clove basil [Ocimum gratissimum L. (Labiatae)] (87 and 71% less, respectively) compared to the control treatment of four water‐sprayed plates surrounding a central plate with ethyl iso‐nicotinate. We also compared the distribution of onion thrips on the plates. Relative thrips numbers on each plate were compared with similar (N, S, E, W, and C) plates in the control treatment. There were relatively lower thrips numbers on the south (23% reduction) and west (26% reduction) O. majorana‐treated plates and higher numbers (37% increase) on the central attractant‐treated plate indicating a short‐distance push–pull effect. When four plates were sprayed with the thrips attractant surrounding a central sticky plate sprayed with an essential oil or water (control), only O. majorana reduced the number of thrips on the attractant‐sprayed plates (62% reduction). The distribution of thrips on the different plates within this treatment combination did not change substantially when compared to the distribution in the water‐control treatment. Other essential oils tested (wormwood [Artemisia arborescens L. (Compositae)]) and tea tree [Melaleuca alternifolia (Maiden. & Betche.) Cheel. (Myrtaceae)]) were not effective in any of the treatments. It appears that O. majorana is a promising thrips repellent which could be used for further testing in a push–pull system with the attractant ethyl iso‐nicotinate. The field setup used also proved to be a valuable tool for evaluating the potential of repellents to control onion thrips.
The effect of Bt maize on Sesamia calamistis in South Africa
Authors: Van den Berg J. , Van Wyk A. 
Published: December 2006

AbstractBt maize, Zea mays L. (Poaceae) expressing Cry 1Ab insecticidal proteins was introduced for control of Busseola fusca (Fuller) (Lepidoptera: Noctuidae) and Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) in South Africa after its development for control of crambid borers in North America. In the light of the reportedly lower toxicity of Bt maize to certain Noctuidae borers, the effect of Bt maize was evaluated on Sesamia calamistis (Hampson) (Lepidoptera: Noctuidae). The characteristic larval behaviour of S. calamistis may result in reduced exposure to Bt toxin and subsequent high levels of survival. Larvae do not feed on plant whorls like other borer species but penetrate stems directly from behind leaf sheaths where eggs are laid. Greenhouse and laboratory bioassays were done with three Bt maize hybrids and their iso‐hybrids. ‘Whole plant methods’ were used and potted plants artificially infested with eggs or larvae and survival recorded over time. Larval survival was also determined on different plant parts (whorls, stems, tillers, and ears) over time. Bt maize was shown to be highly toxic to S. calamistis. No larvae survived longer than 12–18 days on Bt maize plants in any of the experiments. Adults did not differentiate between Bt and non‐Bt plants in oviposition choice experiments. Sesamia calamistis is polyphagous and occurs in mixed populations with other borer species with which it shares many parasitoid species in Africa. The ecological impact of local extinction of S. calamistis caused by this highly effective transgenic event is therefore not expected to be great.
Detection of fungal metabolites of various Trichoderma species by the aphid Schizaphis graminum
Authors: Ganassi Sonia , De Cristofaro Antonio , Grazioso Pasqualina , Altomare Claudio , Logrieco Antonio , Sabatini Maria Agnese 
Published: December 2006

AbstractThe feeding preferences of alate and apterous morphs of the aphid Schizaphis graminum (Rondani) (Homoptera: Aphididae) were evaluated using leaves treated with powdered rice cultures of four fungal isolates belonging to different species of the genus Trichoderma (Deuteromycotina: Hyphomycetes). All of the fungal isolates restrained alate morphs of S. graminum from visiting treated leaves, but only Trichoderma citrinoviride Bisset also influenced the preference of apterous morphs. Trials carried out with supernatants obtained by centrifuging aqueous suspensions of the fungal cultures showed that the feeding preference of aphids was maintained in the absence of fungal spores and mycelia, supporting the hypothesis that at least part of the fungal metabolites responsible for this effect were water‐soluble compounds. Electrophysiological studies showed that the structures involved in the perception of the fungal metabolites are located on the aphid tarsomeres.
Frequency of alleles conferring resistance to Bacillus thuringiensis maize in Louisiana populations of the southwestern corn borer
Authors: Huang Fangneng , Leonard B.Rogers , Cook Donald R. , Lee Donna R. , Andow David A. , Baldwin Jack L. , Tindall Kelly V. , Wu Xiaoyi 
Published: December 2006

AbstractTransgenic maize [Zea mays L. (Poaceae)] expressing Bacillus thuringiensis proteins (Bt maize) has become the most important tool for managing stalk borers in maize in the USA. The current strategy for delaying the evolution of resistance in target insects for Bt maize is referred to as high dose/refuge strategy. A key requirement of the strategy is that initial resistance allele frequencies in field insect populations are low (e.g., <0.001). More than 200 iso‐line families of the southwestern corn borer, Diatraea grandiosella Dyar (Lepidoptera: Crambidae), a major target stalk borer pest of Bt maize, were developed from Louisiana populations and evaluated for Bt resistance using a modified F2 screening method during 2005. No major resistance alleles were detected in these populations. The results showed that the expected Bt resistance allele frequency in the Louisiana populations was <0.0035 with 95% probability and a detection power of 83.9 ± 0.6%. The F2 screen indicates that Bt resistance allele frequencies in D. grandiosella are low among the Louisiana populations and should meet the rare resistance allele requirement of the ‘high dose/refuge’ strategy.
Components of resistance to banana weevil (Cosmopolites sordidus) in Musa germplasm in Uganda
Authors: Kiggundu Andrew , Gold Clifford S. , Labuschagne Maryke T. , Vuylsteke Dirk , Louw Schalk 
Published: December 2006

AbstractA field screening trial undertaken in Uganda showed that a number of Musa L. (Musaceae) cultivars and hybrids displayed high levels of resistance to banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae), while most highland banana cultivars tended to be susceptible to weevil attack. In this study, research was undertaken to determine modalities of resistance to banana weevil. Laboratory studies suggested that all cultivars were attractive to the weevil and that females freely oviposited on all cultivars. While some differences were found between cultivars in attractivity and egg numbers, these were not related to subsequent damage. Therefore, antixenosis does not appear to play an important role in host‐plant resistance to banana weevil. Larval survivorship rates in living corms were, for the most part, low on resistant cultivars, suggesting that antibiosis mechanisms offer the primary avenues of resistance. In the laboratory, development was slower on some resistant cultivars although survivorship rates on excised corm material were not as well related to levels of resistance as that on living material. Sap appeared to play a minor role in reducing egg eclosion rates on some resistant cultivars. Methanol extracts from Kayinja, a resistant cultivar, inhibited larval development on corms of susceptible cultivars in the laboratory.
Measurement of the Incremental Friction Coefficient of Several Homologous Series of Straight‐Chain Hydrocarbon Compounds
Authors: Murray S. F. , Burwell J. T. 
Published: December 2006

SummaryThe incremental friction coefficient fΔ was measured as a function of speed for a number of straight‐chain polar hydrocarbon compounds. These compounds included alcohols, acids, amines, and two esters. In most cases, it was found to be independent of speed at slow speeds and decreased with speed at higher speeds. The amines were the only exception, in that the value of fΔ rose slightly with speed.The constant slow speed value of fΔ was found to decrease generally with increasing chain length in any single homologous series. There seems to be more correlation of the shape of this curve offΔ vs. chain length with the surface metal than with the lubricant type.The friction of mixtures of two acids of rather different chain lengths showed no evidence of any strongly preferential adsorption of either component. This agrees with the relatively small difference in their adsorption energies.The friction of a dibasic acid was high and the damage to the surfaces was great. This agrees with what is known about the orientation of adsorbed molecules of compounds of this type.
The Metal Cutting Process as a Means of Studying the Properties of Extreme Pressure Lubricants
Authors: Shaw Milton C. 
Published: December 2006

AbstractThe cutting of metals by a single point tool involves two main problems of interest to physicists and engineers, namely, the plastic deformation and failure of metals and the friction and wear of sliding surfaces. The material in front of a cutting tool is removed by a process of shear, and fundamental studies of the strength of materials in the fields of solid state physics, engineering plasticity, and physical metallurgy are pertinent to this phase of the cutting process. The material that is detached from the workpiece moves in sliding contact up the face of the cutting tool. The surface of the sliding metal chip is subjected to very high stress, for the entire cutting force is transmitted from the tool to the work material across this surface. The basic principles established by workers in the fields of friction, wear, and lubrication are directly applicable to this second phase of the cutting process. In the present paper, the interrelationship between the shearing and sliding phases of cutting is considered, but only the sliding and frictional aspects of the process are discussed in detail.The cutting process offers a convenient means for studying the frictional properties of metals in sliding contact. By measuring the horizontal and vertical components of force on the tool and the ratio of the length of chip to length of cut, the coefficient of friction between the tool and the chip may be determined. A simple two component force dynamometer is described which enables the coefficient of friction to be determined. Friction data obtained from this dynamometer for specimens of commercially pure aluminum sliding across a hard steel surface in the presence of carefully purified short chain length saturated and unsaturated chlorinated hydrocarbons are presented and discussed. The chemical reactivity of several of the aluminum‐fluid combinations is presented as determined by noting the time required for a chemical reaction to set in when aluminum is kept in contact with the fluid at an elevated temperature. General agreement is seen to exist between the relative reactivity of a fluid toward aluminum and its frictional performance when used in the cutting of aluminum. It is found that cutting fluids in the gaseous state may be equally as effective as those applied in the liquid state. These observations tend to substantiate the view that fluids are effective lubricants in the extreme region of boundary lubrication, embracing metal cutting by virtue of their ability to react chemically with the chip metal to form a low shear strength solid lubricant. Other frictional data for aluminum cut in conjunction with representative members of a number of homologous series are presented and discussed.The paper is concluded by a brief discussion of the inherent advantages of the two dimensional cutting process as a means for studying the frictional characteristics of sliding metal surfaces.