贵州大(虫忽)属一新种(蜻蜓目:绿丝(虫忽)科)

记述采自贵州省雷公山的大属1新种:铲形大Magalestes palaceus,sp.nov.,模式标本保存于浙江自然博物馆昆虫标本室。     

中国萨蜓属分类研究并记述一新种(蜻蜓目,蜓科)

记述萨蜓属Sarasaeschna Karube ＆ Yeh的中国种类共计6种,其中包括1新种,即朱氏萨蜓S.zhuae sp.nov..正模♂,福建省华安县,2007-07-05,徐奇涵采.模式标本存放在漳州城市职业学院生物标本室.给出了萨蜓属中国已知种的名录、地理分布和检索表.新种区别于萨蜓属其它种的主要特征如下:1)在萨蜓属中个体最大;2)脸部总体为棕色,仅后唇基上缘具狭小黄色横带;3)腹部第3～7节基部侧面具大而明显的黄绿色斑;4)上肛附器腹侧亚端部具1半圆形突起.正中处和近基部2/5处各具1小齿;下肛附器长达上肛附器的5/6,为萨蜓属中最长者.     

Changing temperature regimes have advanced the phenology of Odonata in the Netherlands

Abstract.  1. Responses of biota to climate change have been well documented for a restricted number of taxa. This study examined shifts in phenology of 37 species of the aquatic insect order Odonata in the Netherlands over the last decade.
2. The present study shows that adults of the Dutch dragonflies and damselflies have advanced their flight dates over recent years due to complex effects of changing temperature regimes on the timing of adult flight dates.
3. Flight dates did not respond to changes in autumn/winter temperatures, advanced with increases in spring temperatures of the focal and previous year, and delayed with increases in summer temperatures of the previous year. Climate change consequently advanced the flight dates of the Odonata because only spring temperatures have increased during the study period.
4. The findings imply that climate change can evoke strong phenological responses in aquatic insects. Moreover, shifts in phenology due to climate change are likely to vary both spatially or temporally, depending on the exact nature of climate change.     

Differentiation of golden-ringed dragonfly Anotogaster sieboldii (Selys, 1854) (Cordulegastridae: Odonata) in the insular East Asia revealed by the mitochondrial gene genealogy with taxonomic implications

Molecular phylogeographical analyses of Anotogaster sieboldii (Selys, 1854) were conducted to reveal the differentiation process of insular populations. The gene genealogy based on 845 bp of the mitochondrial genes (cytochrome oxidase subunit I and subunit II) indicated that A. sieboldii includes two deeply separated lineages. These two major lineages seem to have differentiated in Miocene before the formation of the insular East Asia. One lineage includes three inner clades that correspond to the populations of northern area (the Japanese main islands, Korean Peninsula, Yakushima), Amamioshima and Okinawajima. Populations of Central Ryukyu, including Amamioshima and Okinawajima, might have been divided from the northern populations in early Pleistocene. The other major lineage includes populations of the Yaeyama Group, Taiwan and East China. The former two populations were reconstructed as a reciprocal monophyletic group. Populations of Taiwan and Yaeyama Groups would have been separated from the continental ones in Pleistocene. These two highly divergent lineages should be recognized as distinct species. Furthermore, the mitochondrial lineages revealed six genetically distinct and geographically isolated assemblages: (1) northern populations, (2) Amamioshima, (3) Okinawajima, (4) Yaeyama Group, (5) Taiwan and (6) East China.     

Procedure for Predicting the Trajectory of Species Recovery Based on the Nested Species Pool Information: Dragonflies in a Wetland Restoration Site as a Case Study

Restoration of seminatural habitats in the rural agricultural landscape has become an urgent matter in environmental conservation. We propose here a procedure for predicting the trajectory of species recovery and for specifying the priority of habitat types for restoration of a rural agricultural landscape. We then apply it as a case study to the recovery of dragonfly species in the Azame restoration project that began in 2003 in northern Kyushu, Japan. We examined the nestedness of the regional distribution of dragonflies using a national database on wildlife distribution and listed the recorded species in order of their prevalence in the region. We also conducted a census of adult dragonflies currently found at the restoration site to assess species richness. By comparing these data, we identified species potentially capable of inhabiting the restoration site and, based on their habitat requirements, suggest what type of habitat (e.g., bogs and marshes, ponds, and bodies of slow‐moving water) should be restored preferentially. We observed significant nestedness in the presence–absence matrix for dragonfly species and thus predict that species recovery at the restoration site will follow the regional order of prevalence of the species. The required habitat types did not differ significantly between the currently observed species and the potential species, which indicates that all these habitat types should be restored in the project.     

Evaluating the Effects of Introduced Rainbow Trout (Oncorhynchus Mykiss) on Native Stream Insects on Kauai Island, Hawaii; Contribution No. 2001-012 to the Hawaii Biological Survey, Bishop Museum

Rainbow trout (Oncorhynchus mykiss) and other salmonids have been widely stocked into upland streams throughout the world to provide a basis for sport fisheries, but the effects of such introductions on indigenous and endemic aquatic insect assemblages are poorly documented. In this study, we examine the impact of rainbow trout on the indigenous and endemic entomofauna of upland streams in Kokee State Park, Kauai, Hawaii, with particular emphasis on the potential threat trout pose to populations of endemic damselflies in the genus Megalagrion. Rainbow trout were introduced into the upland streams of Kauai beginning in the 1920s, with over 60 years of subsequent restocking. This study indicates, however, that streams in this area still maintain diverse populations of Megalagrion damselflies and other indigenous and endemic aquatic insects, both in catchments containing naturally reproducing trout populations and in catchments lacking rainbow trout. Our results indicate that the indigenous and endemic aquatic insect communities in the streams under study compare favorably in terms of density and taxonomic richness with other isolated and unimpacted streams elsewhere in Hawaii, and retain high densities and relative percentages of indigenous and endemic aquatic insect taxa. Our results demonstrate that the threats posed by conspicuous introduced species such as trout should not simply be assumed a priori on the basis of postulated negative interactions, because this may divert limited resources from programs aimed at control of other, potentially more destructive introduced taxa such as inconspicuous poeciliid fishes.     

Quantifying the degree of bias from using county‐scale data in species distribution modeling: Can increasing sample size or using county‐averaged environmental data reduce distributional overprediction?

Citizen‐science databases have been used to develop species distribution models (SDMs), although many taxa may be only georeferenced to county. It is tacitly assumed that SDMs built from county‐scale data should be less precise than those built with more accurate localities, but the extent of the bias is currently unknown. Our aims in this study were to illustrate the effects of using county‐scale data on the spatial extent and accuracy of SDMs relative to true locality data and to compare potential compensatory methods (including increased sample size and using overall county environmental averages rather than point locality environmental data). To do so, we developed SDMs in maxent with PRISM‐derived BIOCLIM parameters for 283 and 230 species of odonates (dragonflies and damselflies) and butterflies, respectively, for five subsets from the OdonataCentral and Butterflies and Moths of North America citizen‐science databases: (1) a true locality dataset, (2) a corresponding sister dataset of county‐centroid coordinates, (3) a dataset where the average environmental conditions within each county were assigned to each record, (4) a 50/50% mix of true localities and county‐centroid coordinates, and (5) a 50/50% mix of true localities and records assigned the average environmental conditions within each county. These mixtures allowed us to quantify the degree of bias from county‐scale data. Models developed with county centroids overpredicted the extent of suitable habitat by 15% on average compared to true locality models, although larger sample sizes (>100 locality records) reduced this disparity. Assigning county‐averaged environmental conditions did not offer consistent improvement, however. Because county‐level data are of limited value for developing SDMs except for species that are widespread and well collected or that inhabit regions where small, climatically uniform counties predominate, three means of encouraging more accurate georeferencing in citizen‐science databases are provided.     

Top predators determine how biodiversity is partitioned across time and space

Natural ecosystems are shaped along two fundamental axes, space and time, but how biodiversity is partitioned along both axes is not well understood. Here, we show that the relationship between temporal and spatial biodiversity patterns can vary predictably according to habitat characteristics. By quantifying seasonal and annual changes in larval dragonfly communities across a natural predation gradient we demonstrate that variation in the identity of top predator species is associated with systematic differences in spatio‐temporal β‐diversity patterns, leading to consistent differences in relative partitioning of biodiversity between time and space across habitats. As the size of top predators increased (from invertebrates to fish) habitats showed lower species turnover across sites and years, but relatively larger seasonal turnover within a site, which ultimately shifted the relative partitioning of biodiversity across time and space. These results extend community assembly theory by identifying common mechanisms that link spatial and temporal patterns of β‐diversity.     

Identification of dragonflies (Odonata) as indicators of general species richness in boreal forest lakes

We argue the need to select indicator species on empirical data to avoid influence of personal opinions. To test an empirical selection process based on a nested subset matrix, we sampled partivoltine dragonfly larvae from 74 small lakes in central Sweden. A nestedness matrix was set up using the 'nestedness temperature calculator' program, selecting 11 species as potential indicators of species richness. These were tested against a known indicator species for water quality (the pool frog) and plant diversity through inventories and comparison to existing surveys of biological values ('rich' lakes vs. 'ordinary' lakes). We could only see a trend towards the pool frog occurring in dragonfly-rich lakes, but found a significant connection between the number of aquatic plants along the shore line and the number of dragonfly species present. A significantly higher number of indicators were encountered in lakes previously surveyed as 'rich' in plants than in lakes classified as 'ordinary'. Dragonfly species richness therefore appears to be positively associated with species richness of vascular plants. We propose nestedness matrices to be a good selecting tool for indicator species, particularly in groups where the biology of the species is not well known. However, it is important to define what such indicators really indicate.     

BIOCHEMICAL EVOLUTION ASSOCIATED WITH ANTIPREDATOR ADAPTATION IN DAMSELFLIES

Previous studies have shown that at least two lineages of Enallagma damselflies (Odonata: Coenagrionidae) shifted from inhabiting lakes with fish as top predators to inhabiting ponds and lakes with large dragonflies as the top predators. In adapting to living with the new predator type, these lineages evolved much greater swimming speeds to avoid attacking dragonflies. In this paper, I test whether biochemical adaptations to fuel swimming arose in concert with previously identified morphological changes that increase swimming speed. I assayed the mass-specific enzyme activities of three enzymes involved in fueling strenuous activity: pyruvate kinase and lactate dehydrogenase (enzymes involved in glycolysis) and arginine kinase (the enzyme that recharges the ATP pool). Enzyme activities were determined for 14 Enallagma species from across the genus. Species that coexist with dragonfly predators had significantly higher mass-specific arginine kinase activities than species that coexist with fish, and the results of evolutionary contrasts analyses indicate that this difference between the two groups is the result of evolutionary change associated with the habitat shifts of lineages from fish lakes to dragonfly lakes. Although significant evolution was documented for lactate dehydrogenase and pyruvate kinase across the genus, evolutionary change in the activities of these enzymes was not consistent with adaptation to coexisting with dragonfly predators. Swimming bouts to avoid dragonfly predators last for only a few seconds, and the action of arginine kinase to phosphorylate ADP to make ATP will extend the duration of maximal exertion for swimming for a few seconds. However, much longer time periods (over 45 sec) are required to generate ATP via glycolysis. Therefore, selection may have favored adaptation only at the arginine kinase locus.