Aphids (Hemiptera: Aphidoidea) on cultivated and self-sown plants in Greece

The present work covers original information on aphids (Hemiptera: Aphidoidea) from Greece during 1995–2005. The individual aphid taxa were collected from their host plants and identified. The plant taxa were classified in two major categories: cultivated and self-sown. The cultivated ones were classified as: herbaceous, climbing and trees. The selfsown ones were classified as: annual herbaceous, annual or biennial herbaceous, biennial or perennial herbaceous, perennial herbaceous, shrubby and trees Two hundred twelve plant taxa were identified on which 105 aphid taxa were recorded. We report 391 plant taxa-aphid taxa associations from which, 190 are referred to cultivated and 201 to self-shown plant taxa. Aphis gossypii was found to infest the widest spectrum of cultivated plant taxa whereas Brachycaudus helichrysi was found to infest the widest spectrum of self-sown plant taxa. Myzus persicae was found to infest the widest spectrum of the total number of plant taxa. Information for several economically unimportant aphid taxa in the area are also presented.     

Achene anatomy and stomatal characteristics of eighteen Crepis L. (Asteraceae) taxa from Turkey with notes on their systematic significance

Achene anatomy and stomatal characteristics of eighteen Crepis taxa from Turkey are here described for the first time. In all taxa examined the pericarp is composed of several layers of sclerenchymatous and parenchymatous cells. As for the achene, differences among taxa mainly concern the pericarp structure and its thickness and width. Stomata are present on both surface of the leaf in all studied taxa and all taxa have anomocytic type stomata. However, the dimensions (length and width) and density of the stomata differ significantly among the studied taxa. In addition, the dimensions of stomata are negatively correlated with stomata density. It is concluded that achene anatomy and stomatal characteristics are useful for delimitation of Crepis taxa and a key to taxa based on these characters is provided. However, based on achene anatomy and stomatal characteristics, we found no argument for an exclusion of the Lagoseris group from Crepis as has previously been proposed.     

Qualitative and quantitative aspects of recent research on helminth parasites

Relationships between the species diversity of different taxa, the mean number of articles published per year on each taxon, and the mean impact factor of the journals in which they appear, were examined across six taxa of helminths: Nematomorpha, Acanthocephala, Monogenea, Trematoda, Cestoda and Nematoda, the latter including only animal parasitic nematodes. The mean annual output of scientific articles per taxon was not related to the species diversity of these taxa or, at least, not significantly. Thus, the large volume of publications on nematodes is not merely a reflection of their estimated diversity. There were significant differences among taxa in the mean impact factor of the journals in which papers on each taxon appeared, with nematodes having the highest mean score, followed by trematodes and cestodes. In addition, across the six taxa, the mean journal impact factor correlated positively and significantly with the mean annual number of papers published: not only are there more papers published on nematodes and trematodes than on nematomorphs or acanthocephalans, but they are also generally published in higher-ranking journals. These results suggest that there is an increasing gap in the quantity and general importance of the research carried out on different helminth taxa.     

The effect of excluding taxa with low abundances or taxa with small distribution ranges on ecological assessment

The present study aims to investigate whether taxa with a small distribution range or taxa with low abundances indicate specific habitats or a high ecological quality and what the effect is if these taxa are excluded from ecological assessment. We compared autecological features between stream dwelling taxa with a mean abundance >5 individuals per sample and a mean abundance ≤5 individuals per sample as well as between taxa with a small distribution range and taxa with a large distribution range. The number of rare taxa (either with a small distribution range or with low abundances) in a sample was related to the ecological quality classes. To test the effect of exclusion of rare taxa we constructed 8 data sets all including 142 samples of Dutch lowland streams. From each data set we stepwise excluded taxa that had low abundances or taxa that were known to be restricted in their distribution range. With help of the AQEM assessment software we calculated the final ecological quality classes and the metrics that were included in the multimetric for the original data and the 8 selected data sets. Autecological features of the taxa within the different selections showed that taxa with small distribution ranges were often running water taxa, living on stones and gravel and indicating oligosaprobic water conditions in contrast to taxa that had a large distribution range. There were only small differences between taxa with low and high abundances. However, current velocity preference was lower for taxa with abundance ≤5 individuals per sample, saprobic values were higher and scores for typical stream habitats, such as lithal, psammal and akal were lower compared to high abundant taxa. If taxa with low abundances were excluded a higher ecological quality class was achieved in most cases, while excluding taxa with a small distribution range resulted in lower ecological quality classes. In conclusion, excluding taxa with a small distribution range led to worse ecological quality classes because these taxa have special autecological features that often indicate natural streams. On the other hand, excluding taxa with low abundances resulted in higher ecological quality classes because these taxa indicate more disturbed situations and because the number of taxa per sample was strongly reduced. Although the documentation of rare taxa (either with low abundances or with small distribution ranges) is often time and cost-intensive regarding field work, laboratory work, data processing, and analyses, the indicative power of these taxa for natural circumstances is essential and therefore rare taxa should be included in ecological assessment studies.     

The impact of rare taxa on a fish index of biotic integrity

The index of biotic integrity (IBI) is a commonly used bioassessment tool that integrates abundance and richness measures to assess water quality. In developing IBIs that are both responsive to human disturbance and resistant to natural variability and sampling error, water managers must decide how to weigh information about rare and abundant taxa, which in turn requires an understanding of the sensitivity of indices to rare taxa. Herein, we investigated the influence of rare fish taxa (within the lower 5% of rank abundance curves) on IBI metric and total scores for stream sites in two of Minnesota's major river basins, the St. Croix (n = 293 site visits) and Upper Mississippi (n = 210 site visits). We artificially removed rare taxa from biological samples by (1) separately excluding each individual taxon that fell within the lower 5% of rank abundance curves; (2) simultaneously excluding all taxa that had an abundance of one (singletons) or two (doubletons); and (3) simultaneously excluding all taxa that fell within the lower 5% of rank abundance curves. We then compared IBI metric and total scores before and after removal of rare taxa using the normalized root mean square error (nRMSE) and regression analysis. The difference in IBI metric and total scores increased as more taxa were removed. Moreover, when multiple rare taxa were removed, the nRMSE was related to sample abundance and to total taxa richness, with greater nRMSE observed in samples with a larger number of taxa or sample abundance. Metrics based on relative abundance of fish taxa were less sensitive to the loss of rare taxa, whereas those based on taxa richness were more sensitive, because taxa richness metrics give more weight to rare taxa compared to the relative abundance metrics.     

Potential impacts of future land use and climate change on the Red List status of the Proteaceae in the Cape Floristic Region, South Africa

Using spatial predictions of future threats to biodiversity, we assessed for the first time the relative potential impacts of future land use and climate change on the threat status of plant species. We thus estimated how many taxa could be affected by future threats that are usually not included in current IUCN Red List assessments. Here, we computed the Red List status including future threats of 227 Proteaceae taxa endemic to the Cape Floristic Region, South Africa, and compared this with their Red List status excluding future threats. We developed eight different land use and climate change scenarios for the year 2020, providing a range of best‐ to worst‐case scenarios. Four scenarios include only the effects of future land use change, while the other four also include the impacts of projected anthropogenic climate change (HadCM2 IS92a GGa), using niche‐based models. Up to a third of the 227 Proteaceae taxa are uplisted (become more threatened) by up to three threat categories if future threats as predicted for 2020 are included, and the proportion of threatened Proteaceae taxa rises on average by 9% (range 2–16%), depending on the scenario. With increasing severity of the scenarios, the proportion of Critically Endangered taxa increases from about 1% to 7% and almost 2% of the 227 Proteaceae taxa become Extinct because of climate change. Overall, climate change has the most severe effects on the Proteaceae, but land use change also severely affects some taxa. Most of the threatened taxa occur in low‐lying coastal areas, but the proportion of threatened taxa changes considerably in inland mountain areas if future threats are included. Our approach gives important insights into how, where and when future threats could affect species persistence and can in a sense be seen as a test of the value of planned interventions for conservation.     

The effect of excluding diatom taxa and reducing taxonomic resolution on multivariate analyses and stream bioassessment

The goal of the present study was to evaluate whether the Eastern Canadian Diatom Index (IDEC: Indice Diatomées de l’Est du Canada), which was built on fine-scale taxonomic resolution and included all observed diatom taxa, would perform similarly if a number of taxa were excluded from the analyses or if a reduced level of taxonomic resolution was used. The effects of excluding taxa and reducing the taxonomic resolution were evaluated by studying community structure variations in ordination analyses, and more specifically by comparing IDEC values calculated from the original diatom matrix with IDEC values obtained from simplified diatom matrices. The results showed that the exclusion of taxa based on the relative abundance criterion is the most appropriate, while the exclusion of taxa based on the frequency of occurrence criterion greatly affected the structure of the ordination. More specifically, taxa with a maximum relative abundance <2% can be excluded from the CA without markedly affecting the results. As a result, 125 taxa (40%) were excluded from the 311 taxa included in the original matrix without significantly affecting the performance of the IDEC. Excluding a greater number of taxa still allows for the distinction between impacted and reference sites, although subtle changes in the ecological status are lost. Ordinations based on presence/absence or genus-level identification resulted in a loss of information on subtle changes, but gross separation between impacted and reference sites was still possible.     

紫花苜蓿复合体(Medicago sativa complex)叶片形态特征及数量分类研究

运用比较形态学和比较解剖学方法,使用扫描电镜和光学显微镜对紫花苜蓿复合体(Medicago sativa complex)6个分类群的叶片形态特征和叶片解剖结构进行了观察和比较,并以15个叶片表征形态性状为基础,采用聚类分析法(UPGMA)和主成分分析方法(PCA)对6个分类群进行了数量分类研究.观察结果表明:各分类群叶片的上、下表皮多为不规则形细胞;垂周壁呈深浅不一的波状;气孔器为不规则型,具有蜡质气孔盖,气孔密度有一定差异.6个分类群的叶片均为薄纸质型,厚度130～170 μm,表皮细胞切面近圆形或近长方形;栅栏组织细胞1～2层,厚度41～68 μm,细胞排列紧密;海绵组织厚度32～75 μm,细胞排列疏松;不同分类群叶片的组织疏松度和组织紧缩度有一定的差异,大花苜蓿(M. trautvetterii Sumnev. )叶片的组织疏松度最高,紫花苜蓿叶片的组织紧缩度最高.UPGMA结果显示:在结合线1.53处可将6个分类群划分为2支,其中,黄花苜蓿(M. falcata L. )独立为一支,其余5个分类群聚成另一支;在结合线1.18处,第2支又被分成2个亚支,其中一个亚支包含紫花苜蓿和天山苜蓿(M. tianschanica Vassilcz. ),另一个亚支则包含西锡金苜蓿(M. schischkinii Sumnev. )、座垫苜蓿(M. rivularis Vassilcz. )和大花苜蓿.PCA结果表明:对紫花苜蓿复合体而言,叶片表皮细胞形状、垂周壁式样、轴性分化特征、组织疏松度和气孔密度等特征具有较好的分类价值;基于主成分分析的Q分布图与聚类分析结果也具有较高的一致性.根据本研究结果及前人的研究结果,认为国产的紫花苜蓿复合体应包含3个分类群,即紫花苜蓿、黄花苜蓿及多变苜蓿(M. varia Martyn).此外,西锡金苜蓿、座垫苜蓿、天山苜蓿和大花苜蓿等杂交后代分类群的性状分化不稳定,应属于多变苜蓿的同种异名植物.     

Wood‐Associated Macroinvertebrate Fauna in Central European Streams

An overview of macroinvertebrates associated with wood debris is given, with the main focus on Central European fauna. In general, three categories of macroinvertebrate wood relations are distinguished: taxa frequently associated with wood but not xylophagous, facultative xylophagous taxa and obligate xylophagous taxa. The adaptations in the life history, ethology and physiology of species representing these three groups are reviewed. From literature and our own investigations, 15 taxa inhabiting Central European freshwater ecosystems are known to be obligate xylophagous, 22 taxa are facultatively xylophagous. From field observations another 41 taxa presumably feed on wood although no gut content analyses and laboratory experiments have yet been carried out. From 25 taxa other forms of close association to CWD are known (feeding on epixylic biofilm, use as a refuge, or as an attachment point). Possible pathways of xylophagy evolution are discussed and unresolved aspects of aquatic invertebrate wood relations are listed.     

Invertebrate predation on planktonic rotifers

Representatives from many taxa including the Protozoa, Cnidaria, Rotifera, Cladocera, Cyclopoida, Calanoida, Harpacticoida, Chaoboridae, and Mysidacea are reported to feed on rotifers. There are few good quantitative data on predation on rotifers by any of these taxa with two exceptions, Rotifera and Cyclopoida. The present review focuses on the dynamics of Cyclopoid copepod predation. Intense and selective cyclopoid copepod predation makes it an important factor to consider in studies of the population ecology and community structure of rotifer populations. Limited information available on other predatory invertebrate taxa suggests that rotifer production may contribute extensively to their diets.     

Morphology and microhabitat preferences of benthic foraminifera from the northwest Atlantic Ocean

The distribution of Rose Bengal stained calcareous benthic foraminifera was determined in six ☐ cores raised from water depths between 200 and 3000 m on the Nova Scotian continental margin and Gulf of Maine. The taxa can be separated into four microhabitats within the surficial sediments. Epifaunal taxa are generally found in the top cm, intermediate infaunal taxa are found from about 1 to 4 cm and deep infaunal taxa are found at > 4 cm sediment depth in at least one ☐ core. A fourth group, shallow infaunal taxa, is found in the top 2 cm and is inferred to be infaunal based on wall porosity characteristics and test shapes similar to infaunal taxa. The epifaunal, shallow infaunal and intermediate infaunal taxa maintain their positions within the sediments from core to core, whereas the deep infaunal taxa are found at progressively shallower sediment depths in cores within increasing organic carbon contents from shallower water depths.Each microhabitat category has distinct morphological characteristics. Epifaunal taxa have plano-covex or biconvex cross sections, trochospiral coiling and large pores absent or found on only one side. Shallow infaunal taxa have uniserial, triserial, or planispiral coiling, with surface ornamentation present on a number of taxa. The intermediate infaunal taxa have rounded peripheries, pores over the entire test and planispiral coiling, with the exception ofCibicidoides bradyi which has trochospiral coiling. The deep infaunal taxa have, in general, planispiral or triserial coiling with cylindrical or ovate shaped tests.     

Selection of nontarget arthropod taxa for field research on transgenic insecticidal crops: using empirical data and statistical power

One of the possible adverse effects of transgenic insecticidal crops is the unintended decline in the abundance of nontarget arthropods. Field trials designed to evaluate potential nontarget effects can be more complex than expected because decisions to conduct field trials and the selection of taxa to include are not always guided by the results of laboratory tests. Also, recent studies emphasize the potential for indirect effects (adverse impacts to nontarget arthropods without feeding directly on plant tissues), which are difficult to predict because of interactions among nontarget arthropods, target pests, and transgenic crops. As a consequence, field studies may attempt to monitor expansive lists of arthropod taxa, making the design of such broad studies more difficult and reducing the likelihood of detecting any negative effects that might be present. To improve the taxonomic focus and statistical rigor of future studies, existing field data and corresponding power analysis may provide useful guidance. Analysis of control data from several nontarget field trials using repeated-measures designs suggests that while detection of small effects may require considerable increases in replication, there are taxa from different ecological roles that are sampled effectively using standard methods. The use of statistical power to guide selection of taxa for nontarget trials reflects scientists' inability to predict the complex interactions among arthropod taxa, particularly when laboratory trials fail to provide guidance on which groups are more likely to be affected. However, scientists still may exercise judgment, including taxa that are not included in or supported by power analyses.     

Phylogeny and systematics of the subfamily Bryocorinae based on morphology with emphasis on the tribe Dicyphini sensu Schuh,

The classification of the hyperdiverse true bug family Miridae is far from settled, and is particularly contentious for the cosmopolitan subfamily Bryocorinae. The morphological diversity within the subfamily is pronounced, and a lack of explicit character formulation hampers stability in the classification. Molecular partitions are few and only a handful of taxa have been sequenced. In this study the phylogeny of the subfamily Bryocorinae has been analysed based on morphological data alone, with an emphasis on evaluating the tribe Dicyphina sensu Schuh, 1976, within which distinct groups of taxa exist. A broad sample of taxa was examined from each of the bryocorine tribes. A broad range of outgroup taxa from most of the other mirid subfamilies was also examined to test for bryocorine monophyly, ingroup relationships and to determine character polarity. In total a matrix comprising 44 ingroup, 15 outgroup taxa and 111 morphological characters was constructed. The phylogenetic analysis resulted in a monophyletic subfamily Bryocorinae sensu Schuh (1976, 1995), except for the genus Palaucoris, which is nested within Cylapinae. The tribe Dicyphini sensu Schuh (1976, 1995) has been rejected. The subtribe Odoniellina is synonymized with the subtribe Monaloniina and the subtribes Dicyphina, Monaloniina and Eccritotarsina are now elevated to tribal level, with the Dicyphini now restricted in composition and definition. The genus Felisacus is highly autapomorphic and a new tribe – the Felisacini – is erected for the included taxa. This phylogeny of the tribes of the Bryocorinae comprises the following sister‐group relationships: Dicyphini ((Bryocorini + Eccritotarsini)(Felisicini + Monaloniini)).     

Two new genera of cyclopinid copepods (Crustacea) from anchihaline caves on western Mediterranean and eastern Atlantic islands

Troglocyclopina balearica gen nov. ap. nov. and Muceddina multispinosa gen nov. sp. nov. are described from the flooded coastal karst of the Balearic Islands, and from caves on Sardinia, the Balearics, and Lanzarote (Canaries), respectively. Both taxa seem to prefer anchihaline habitats with water salinities in excess of 18%, although Troglocyclopina has also been found in more reduced salinity cave lakes located some distance from the coast. These new taxa are the first cyclopinids to be reported from caves, all previous citations of cyclopinids from hypogean environments relate only to the marine interstitial. The small clutch-size exhibited by Troglocyclopina balearica (two eggs per sac) and the absence of the exopodal seta on the antenna at Muceddina multispinosa are interpreted as troglomorphic features, in addition to the absence of the nauplius eye and the lack of body pigmentation in both taxa. The derivation of both taxa from shallow-water, hyperbenthic marine ancestors is proposed.     

A study on intersterility groups of Armillaria in China

Mating tests were used to identify 282 basidiocarp specimens of Armillaria collected in 15 Chinese provinces, mostly in northern and southwestern parts of the country. Fourteen intersterile taxa were found, including the species A. borealis, A. gallica, A. mellea s.str., A. ostoyae, A. sinapina and A. tabescens and eight so far unnamed taxa called Chinese Biological Species (CBS) C, F, G, H, J, L, N and O. The CBS F might be A. singula, previously recorded from Japan, but six Chinese groups, C, H, J, L, N and O, are probably new biological species. The sexual system of 13 taxa is tetrapolar heterothallism. Homothallic forms also were found; they show a low degree of sexual compatibility with A. mellea s.str. and tentatively are included in the CBS G, but it is unclear whether this is a homogeneous group. Notes are presented on the distribution and ecology of the identified taxa.     

Modelling the effects of dams on freshwater fish distributions in Hokkaido, Japan

1. We examined the effects of habitat fragmentation caused by dams on freshwater fish species using a database of 7848 fish presence/absence surveys, conducted between 1953–2003 in Hokkaido, Japan. 2. A series of generalised linear models showed that for 11 of 41 taxa examined, the probability of occurrence had been influenced either negatively (eight taxa) or positively (three taxa) by the presence of a dam downstream from their habitat. 3. Maps of modelled predictions revealed that dams had had widespread negative impacts on certain taxa, while for other taxa the impact was limited to specific basins. Two of the three taxa whose probability of occurrence was increased in areas above dams have long been transplanted into reservoirs in Japan. 4. For four of the eight taxa whose probability of occurrence was reduced above dams and all three taxa whose probability of occurrence increased above dams, the temporal length of habitat isolation (i.e. the number of years between dam construction and sampling) was also a significant predictor of the probability of occurrence. This pattern indicates that these taxa experienced a gradual rather than an instantaneous population impact as a result of dam construction. 5. The eight taxa whose probability of occurrence was reduced as a consequence of dams all exhibit migratory life cycles. Although migratory taxa are probably more susceptible to the negative effect of dams, we could not detect significant relationships between migration life histories and the effect of fragmentation by dams. 6. These analyses enable stream and fisheries managers to quantify the impacts of habitat fragmentation because of dams for individual species. The spatially explicit nature of our analyses also enables identification of the areas of the impact at broad geographical scales. Using our results, managers can take effective conservation and restoration measures to predict, mitigate or remove the impact of dams. For example, our results can be used to prioritise dams for removal or to predict losses of biodiversity and ecosystem services in advance of dam construction.     

Invertebrate diversity on

Despite the global importance of New Zealands invertebrates, relatively little is known about them and their relationships with plants and plant communities in native habitats. Invertebrate diversity was examined by beating randomly chosen shrubs of the species Olearia bullata (Asteraceae) and Coprosma propinqua(Rubiaceae). Invertebrate taxon richness was assessed initially using morphospecies, which were identified subsequently by expert taxonomists. Though the taxon richness of invertebrates recorded from O. bullata was not significantly higher than that on C. propinqua (except for the orders Diptera and Hemiptera), there was a clear indication that O. bullata hosts a higher diversity of invertebrates. Mean number of taxa per shrub for O. bullata was higher in all cases (except Coleoptera), and so was the maximum number of taxa per shrub. Overall, O. bullata yielded 115 invertebrate taxa compared with 93 for C. propinqua. Moreover, 50 invertebrate taxa were restricted to O. bullata compared with 28 for C. propinqua. Since at least ten species of Oleariaare threatened or uncommon, this could be cause for concern with respect to the maintenance of invertebrate diversity. Therefore, sites where Oleariaspecies are still present are likely to be of significance for invertebrate conservation.     

Interspecific hybridization in natural populations ofCyrtandra (Gesneriaceae) on the Hawaiian Islands: Evidence from RAPD markers

Interspecific hybridization among Hawaiian species ofCyrtandra (Gesneriaceae) was investigated using randomly amplified polymorphic DNA (RAPD) markers. Thirty-three different primers were used to investigate interspecific hybridization for 17 different putative hybrids based on morphological intermediacy and sympatry with putative parental species. RAPD data provided evidence for the hybrid origin of all putative hybrid taxa examined in this analysis. However, the patterns in the hybrid taxa were not found to be completely additive of the patterns found in the parental species. Markers missing in the hybrid taxa can be attributed to polymorphism in the populations of the parental species and the dominant nature of inheritance for RAPD markers. Unique markers found within hybrid taxa require further explanation but do not necessarily indicate that the taxa are not of hybrid origin. The implications suggest that these interspecific hybridization events had, and continue to have, an effect on the adaptive radiation and conservation biology ofCyrtandra.     

Negative effects of urbanisation on diurnal and nocturnal pollen-transport networks

Pollinating insects are declining due to habitat loss and climate change, and cities with limited habitat and floral resources may be particularly vulnerable. The effects of urban landscapes on pollination networks remain poorly understood, and comparative studies of taxa with divergent niches are lacking. Here, for the first time, we simultaneously compare nocturnal moth and diurnal bee pollen-transport networks using DNA metabarcoding and ask how pollination networks are affected by increasing urbanisation. Bees and moths exhibited substantial divergence in the communities of plants they interact with. Increasing urbanisation had comparable negative effects on pollen-transport networks of both taxa, with significant declines in pollen species richness. We show that moths are an important, but overlooked, component of urban pollen-transport networks for wild flowering plants, horticultural crops, and trees. Our findings highlight the need to include both bee and non-bee taxa when assessing the status of critical plant-insect interactions in urbanised landscapes.