The ongoing biodiversity crisis becomes evident in the widely observed decline in abundance and diversity of species, profound changes in community structure, and shifts in species’ phenology. ...Insects are among the most affected groups, with documented decreases in abundance up to 76% in the last 25–30 years in some terrestrial ecosystems. Identifying the underlying drivers is a major obstacle as most ecosystems are affected by multiple stressors simultaneously and in situ measurements of environmental variables are often missing. In our study, we investigated a headwater stream belonging to the most common stream type in Germany located in a nature reserve with no major anthropogenic impacts except climate change. We used the most comprehensive quantitative long‐term data set on aquatic insects available, which includes weekly measurements of species‐level insect abundance, daily water temperature and stream discharge as well as measurements of additional physicochemical variables for a 42‐year period (1969–2010). Overall, water temperature increased by 1.88 °C and discharge patterns changed significantly. These changes were accompanied by an 81.6% decline in insect abundance, but an increase in richness (+8.5%), Shannon diversity (+22.7%), evenness (+22.4%), and interannual turnover (+34%). Moreover, the community's trophic structure and phenology changed: the duration of emergence increased by 15.2 days, whereas the peak of emergence moved 13.4 days earlier. Additionally, we observed short‐term fluctuations (<5 years) in almost all metrics as well as complex and nonlinear responses of the community toward climate change that would have been missed by simply using snapshot data or shorter time series. Our results indicate that climate change has already altered biotic communities severely even in protected areas, where no other interacting stressors (pollution, habitat fragmentation, etc.) are present. This is a striking example of the scientific value of comprehensive long‐term data in capturing the complex responses of communities toward climate change.
Cambios Complejos y No Lineales Causados por el Clima en Comunidades de Insectos de Agua Dulce durante 42 Años
Resumen
La continua crisis de la biodiversidad se vuelve evidente en la ampliamente documentada declinación en la abundancia y diversidad de especies, cambios profundos en la estructura de las comunidades y modificaciones en la fenología de las especies. Los insectos se encuentran entre los grupos más afectados; se han documentado reducciones en la abundancia de hasta el 76% en los últimos 25–30 años en algunos ecosistemas terrestres. La identificación de los causantes subyacentes es un gran obstáculo porque la mayoría de los ecosistemas están afectados por varios factores estresantes simultáneamente y con frecuencia faltan las medidas in situ de las variables ambientales. Investigamos un flujo naciente perteneciente al tipo de arroyo más común en Alemania ubicado dentro de una reserva natural sin impactos antropogénicos importantes a excepción del cambio climático. Usamos el conjunto más completo disponible de datos cuantitativos de largo plazo para insectos acuáticos que incluye las medidas semanales de abundancia de insectos a nivel especie, las medidas diarias de la temperatura del agua y la descarga del flujo y las medidas de variables físico‐químicas adicionales durante 42 años (1969 ‐ 2010). En general, la temperatura del agua incrementó 1.88°C y los patrones de descarga cambiaron significativamente. Estos cambios estuvieron acompañados por una declinación del 81.6% en la abundancia de insectos, pero también de un incremento en la riqueza (+8.5%), la diversidad Shannon (+22.7%), la uniformidad (+22.4%) y la renovación interanual (+34%). Además, la estructura trófica y la fenología de la comunidad cambiaron: la duración del surgimiento incrementó en 15.2 días y el pico del surgimiento ocurrió con 13.4 días de anticipación. Observamos fluctuaciones a corto plazo (<5 años) en casi todas las medidas, así como respuestas complejas y no lineales de la comunidad hacia el cambio climático que podrían haber sido ignoradas si sólo se usaran datos instantáneos o series de tiempo más cortas. Nuestros resultados indican que el cambio climático ya ha alterado seriamente a las comunidades bióticas, incluso en áreas protegidas en las que no están presentes otros factores estresantes en interacción (contaminación, fragmentación del hábitat, etc.). Ésto es un ejemplo notable del valor científico que tienen los datos completos de escalas de tiempo a largo plazo para la captura de las respuestas complejas de las comunidades ante el cambio climático.
摘要
当前的生物多样性危机表现为物种数量和丰度的普遍下降、群落结构的明显变化和生物物候学的转变。昆虫是受影响最严重的群体之一; 记录表明, 过去25‐30年间一些陆地生态系统昆虫丰度的下降高达 76% 。然而, 确定潜在的驱动因素仍阻碍重重, 因为大多数生态系统同时受到多种压力的影响, 且又常常缺少对环境变量的现场测量。本研究调查了德国最常见河流类型中的一条源头溪流, 它位于一个自然保护区内, 除气候变化外没有受到重大的人为影响。我们利用了目前水生昆虫最全面的长期定量数据集, 包括每周测量的昆虫物种丰度、每日水温和溪流流量, 以及42年来 (1969‐2010年) 其它物理化学变量的观测数据。总体而言, 水温升高1.88°C , 流量就会发生明显变化。同时, 昆虫丰度下降81.6% , 但物种多样性增加 (+8.5%) , Shannon多样性增加 (+22.7%) , 均匀度增加 (+22.4%) 以及年际周转率增加 (+34%) 。此外, 群落营养结构和物候也发生了变化: 物种出现时间增加了15.2天, 出现高峰提前了 13.4 天。我们发现几乎所有指标都存在短期波动 (<5年) , 且群落对气候变化存在复杂的非线性响应, 这些变化是简单使用快照数据或更短的时间序列数据难以捕捉的。我们的研究结果表明, 即使在没有其它交互压力 (污染、栖息地破碎化等) 的保护区内, 气候变化也已经严重地改变了生物群落。这个惊人的案例说明综合的长期数据在记录群落对气候变化的复杂响应中具有重要科学价值。【翻译: 胡怡思; 审校: 聂永刚】
Article impact statement: In a nature reserve, climate change can lead to a significant decline in insect abundance and severe restructuring of communities.
Anthropogenic environmental change can underpin major shifts in natural selective regimes, and can thus alter the evolutionary trajectories of wild populations. However, little is known about the ...evolutionary impacts of deforestation—one of the most pervasive human-driven changes to terrestrial ecosystems globally. Absence of forest cover (i.e. exposure) has been suggested to play a role in selecting for insect flightlessness in montane ecosystems. Here, we capitalize on human-driven variation in alpine treeline elevation in New Zealand to test whether anthropogenic deforestation has caused shifts in the distributions of flight-capable and flightless phenotypes in a wing-polymorphic lineage of stoneflies from the
Zelandoperla fenestrata
species complex. Transect sampling revealed sharp transitions from flight-capable to flightless populations with increasing elevation. However, these phenotypic transitions were consistently delineated by the elevation of local treelines, rather than by absolute elevation, providing a novel example of human-driven evolution in response to recent deforestation. The inferred rapid shifts to flightlessness in newly deforested regions have implications for the evolution and conservation of invertebrate biodiversity.
Abstract
To elucidate the effect of Pleistocene climatic fluctuations on the historical distribution and geographical genetic structure of temperate Japanese species, we performed phylogeographical ...and demographic analyses using mitochondrial gene sequences obtained from the stonefly species Kamimuria tibialis, sampled from four main islands of the Japanese Archipelago (i.e. Hokkaido, Honshu, Shikoku and Kyushu) and Tsushima Island. We detected three main clades with distinct geographical distributions, including the Tsushima, Kyushu and Hokkaido–Honshu–Shikoku phylogroups. These groups were estimated to have diverged from one another 0.54–2.02 Mya, suggesting they have undergone several glacial cycles in different refugia. Our results showed that during the glacial epochs and with a fall in sea-level, gene flow was limited among Tsushima and Kyushu, and among Hokkaido and Honshu, probably because the straits between these islands are deep. The population in Kyushu and Shikoku, the southernmost islands, exhibited high genetic diversity, with two distinct haplotype lineages occurring sympatrically. These results suggest that the population division into multiple refugia and the existence of stable southern refugia have contributed to the high genetic diversity of the species in this region.
We present a genome assembly from an individual male
(black needle fly; Arthropoda; Insecta; Plecoptera; Leuctridae). The genome sequence is 536.3 megabases in span. Most of the assembly is ...scaffolded into 13 chromosomal pseudomolecules
including the X sex chromosome. The mitochondrial genome has also been assembled and is 17.6 kilobases in length.
The evolution of Batesian mimicry – whereby harmless species avoid predation through their resemblance to harmful species – has long intrigued biologists. In rare cases, Batesian mimicry is linked to ...intraspecific colour variation, in which only some individuals within a population resemble a noxious ‘model’. Here, we assess intraspecific colour variation within a widespread New Zealand stonefly, wherein highly melanized individuals of Zelandoperla closely resemble a chemically defended aposematic stonefly, Austroperla cyrene. We assess convergence in the colour pattern of these two species, compare their relative palatability to predators, and use genome‐wide association mapping to assess the genetic basis of this resemblance. Our analysis reveals that melanized Zelandoperla overlap significantly with Austroperla in colour space but are significantly more palatable to predators, implying that they are indeed Batesian mimics. Analysis of 194,773 genome‐wide SNPs reveals an outlier locus (ebony) strongly differentiating melanic versus non‐melanic Zelandoperla. Genotyping of 338 specimens from a single Zelandoperla population indicates that ebony explains nearly 70% of the observed variance in melanism. As ebony has a well‐documented role in insect melanin biosynthesis, our findings indicate this locus has a conserved function across deeply divergent hexapod lineages. Distributional records suggest a link between the occurrence of melanic Zelandoperla and the forested ecosystems where the model Austroperla is abundant, suggesting the potential for adaptive shifts in this system underpinned by environmental change.
The infraorder Systellognatha is the most species-rich clade in the insect order Plecoptera and includes six families in two superfamilies: Pteronarcyoidea (Pteronarcyidae, Peltoperlidae, and ...Styloperlidae) and Perloidea (Perlidae, Perlodidae, and Chloroperlidae). To resolve the debatable phylogeny of Systellognatha, we carried out the first mitochondrial phylogenetic analysis covering all the six families, including three newly sequenced mitogenomes from two families (Perlodidae and Peltoperlidae) and 15 published mitogenomes. The three newly reported mitogenomes share conserved mitogenomic features with other sequenced stoneflies. For phylogenetic analyses, we assembled five datasets with two inference methods to assess their influence on topology and nodal support within Systellognatha. The results indicated that inclusion of the third codon positions of PCGs, exclusion of rRNA genes, the use of nucleotide datasets and Bayesian inference could improve the phylogenetic reconstruction of Systellognatha. The monophyly of Perloidea was supported in the mitochondrial phylogeny, but Pteronarcyoidea was recovered as paraphyletic and remained controversial. In this mitochondrial phylogenetic study, the relationships within Systellognatha were recovered as (((Perlidae + (Perlodidae + Chloroperlidae)) + (Pteronarcyidae + Styloperlidae)) + Peltoperlidae).
•First two perlodid mitogenomes and the second one from Peltoperlidae are sequenced.•The first mitochondrial phylogenetic analysis of Systellognatha is performed.•The monophyly of Perloidea is supported in the mitochondrial phylogeny.•Pteronarcyoidea is recovered as paraphyletic by mitochondrial data.
The last nymphal instars of Anacroneuria planicollis Klapálek, 1923 and A. quetzali Gutiérrez-Fonseca and Springer, 2015 are described from the Caldera River, Chiriquí Province, Panamá. The adult ...female of A. quetzali is associated for the first time and described also from the Caldera River, Chiriquí Province, Panamá.
DNA barcoding is an essential tool in modern biodiversity sciences. Despite considerable work to barcode the tree of life, many groups, including insects, remain partially or totally unreferenced, ...preventing barcoding from reaching its full potential. Aquatic insects, especially the three orders Ephemeroptera, Plecoptera, and Trichoptera (EPT), are key freshwater quality indicators worldwide. Among them, Plecoptera (stoneflies), which are among the most sensitive aquatic insects to habitat modification, play a central role in river monitoring surveys. Here, we present an update of the Plecoptera reference database for (meta)barcoding in Switzerland, now covering all 118 species known from this country. Fresh specimens, mostly from rare or localized species, were collected, and 151 new CO1 barcodes were generated. These were merged with the 422 previously published sequences, resulting in a dataset of 573 barcoded specimens. Our CO1 dataset was delimited in 115 CO1 clusters based on a priori morphological identifications, of which 17% are newly reported for Switzerland, and 4% are newly reported globally. Among the 115 CO1 clusters, 85% showed complete congruence with morphology. Distance-based analysis indicated local barcoding gaps in 97% of the CO1 clusters. This study significantly improves the Swiss reference database for stoneflies, enhancing future species identification accuracy and biodiversity monitoring. Additionally, this work reveals cryptic diversity and incongruence between morphology and barcodes, both presenting valuable opportunities for future integrative taxonomic studies. Voucher specimens, DNA extractions and reference barcodes are available for future developments, including metabarcoding and environmental DNA surveys.
Land‐use changes have degraded ecosystems worldwide. A particular concern for freshwater biodiversity and ecosystem function are stressors introduced by intensified agriculture. Typically several ...stressors affect freshwater ecosystems simultaneously. However, the combined effects of these multiple stressors on streams and rivers are still poorly understood, yet of critical importance to improve freshwater management. We investigated responses of benthic macroinvertebrates to three globally important agricultural stressors affecting streams (nutrient enrichment, fine sediment deposition and reduced current velocity), using 64 stream mesocosms (full‐factorial 2 × 2 × 2 design, eight replicates of each treatment combination) established on the banks of the Breitenbach Stream (Hesse, Germany). The experiment ran for 1 month (16 days of colonisation, 14 days of manipulations), and all invertebrates in the mesocosms were collected at the end of this period. Fourteen of the 17 studied invertebrate response variables were affected by one or more stressors each. Negative effects on richness or abundance of pollution‐sensitive Ephemeroptera, Plecoptera and Trichoptera (EPT) taxa were particularly common. Overall, both sediment addition and stream flow velocity reduction had pervasive and strong effects. Responses to sediment addition were mostly negative, whereas decreased current velocity reduced several EPT metrics but increased the abundances of some of the other common taxa. Nutrient enrichment had few effects, but these were consistently negative. Combined stressor effects were mainly additive, with only two interactions found in total, both between reduced velocity and nutrients (on the crustacean Gammarus spp. and ceratopogonid midges). This finding implies that multiple‐stressor responses may be predicted from knowledge of single‐stressor effects in this stream community (unlike the often synergistic or antagonistic responses observed elsewhere). However, further taxon‐specific responses and interactions among stressors may have been obscured by limited taxonomic resolution, especially for the numerically dominant Chironomidae. Genetic approaches are required to address this limitation in the future.
The complete mitochondrial genomes (mitogenomes) of Taeniopteryx ugola and Doddsia occidentalis (Plecoptera: Taeniopterygidae) were firstly sequenced from the family Taeniopterygidae. The 15,353-bp ...long mitogenome of T. ugola and the 16,020-bp long mitogenome of D. occidentalis each contained 37 genes including 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs) and a control region (CR). The mitochondrial gene arrangement of the two taeniopterygids and other stoneflies was identical with the putative ancestral mitogenome of Drosophila yakuba. Most PCGs used standard ATN start codons and TAN termination codons. Twenty-one of the 22 tRNAs in each mitogenome could fold into the cloverleaf secondary structures, while the dihydrouridine (DHU) arm of trnSer (AGN) was reduced or absent. Stem-loop (SL) structures, poly-T stretch, poly-ATn stretch and tandem repeats were found in the CRs of the two mitogenomes. The phylogenetic analyses using Bayesian inference (BI) and maximum likelihood methods (ML) generated identical results, both supporting the monophyly of all stonefly families and the two infraorders, Systellognatha and Euholognatha. Taeniopterygidae was grouped with another two families from Euholognatha. The relationships within Plecoptera were recovered as (((Perlidae+Peltoperlidae)+((Pteronarcyidae+Chloroperlidae)+Styloperlidae))+((Capniidae+Taeniopterygidae)+Nemouridae))+Gripopterygidae.
•First two complete mitogenomes from Taeniopterygidae are sequenced.•The mitochondrial phylogenetic analysis of available stonefly mitogenomes is performed.•Size variation is observed in the two mitogenomes from the same family Taeniopterygidae.•The monophyly of each family and infraorder is supported in the mitochondrial phylogeny.
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