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This essay explores the history of the discovery and study of Plecoptera (stoneflies) in Britain and Ireland from 1769 to the 1970s. Britain (35 species) and Ireland (19 species) have a depauperate representation of this insect group compared to continental Europe but they form an important component of freshwater ecosystems on both islands. Species discovery began in the eighteenth century and led to extensive specimen collecting in the 1800s and early 1900s. This was followed by a period of classification and consolidation of species, genera and families through the mid-twentieth century which eventually led to more detailed studies of stonefly ecology in the mid- to late 1900s. The entomologists involved are detailed along with how their works and interests played a significant role in shaping knowledge about British and Irish stoneflies. This essay also touches on many other prominent entomologists and their collections, studies and publications that have helped progress understanding of this insect order over the past two centuries. [ABSTRACT FROM AUTHOR]

Maccaffertium annae sp. n. is described in the Mexican amber of early Miocene age. It constitutes the first species of mayfly (Ephemeroptera), the first record of the family Heptageniidae to be described from this amber, and also the first fossil record of the genus Maccaffertium. The species is represented by male and female imagos in one piece of amber. [ABSTRACT FROM AUTHOR]

1. Freshwater ecosystems cover less than 1% of the planet's surface but support up to 10% of known species. Around 25% of freshwater invertebrate species are under threat of extinction. Such a decline in species richness is likely to lead to adverse effects on the delivery of services. However, the effect of species loss on ecosystem goods and services can only be assessed once the link between species diversity and ecosystem goods and services has been established and better understood. 2. Using a flexible systematic literature review search protocol, we were able to identify a range of ecosystem goods and services provided by freshwater insects in the categories of provisioning, supporting, and cultural services. 3. The ecosystem services and benefits provided by freshwater insects are diverse and unexpectedly wide-ranging including decomposition and nutrient cycling, food for a wider range of species including humans, and the inspiration for art, music, and literature. Several of these have clear economic values but are not currently fully exploited. 4. The identification of goods and services may bring greater appreciation and impetus to understanding the scale of their importance, economic value, and conservation. In the absence of freshwater insects, few other service providers could replicate the same level and degree of service. [ABSTRACT FROM AUTHOR]

This work is intended as a general and concise overview of Ephemeroptera biology, diversity, and services provided to humans and other parts of our global array of freshwater and terrestrial ecosystems. The Ephemeroptera, or mayflies, are a small but diverse order of amphinotic insects associated with liquid freshwater worldwide. They are nearly cosmopolitan, except for Antarctica and some very remote islands. The existence of the subimago stage is unique among extant insects. Though the winged stages do not have functional mouthparts or digestive systems, the larval, or nymphal, stages have a variety of feeding approaches—including, but not limited to, collector-gatherers, filterers, scrapers, and active predators—with each supported by a diversity of morphological and behavioral adaptations. Mayflies provide direct and indirect services to humans and other parts of both freshwater and terrestrial ecosystems. In terms of cultural services, they have provided inspiration to musicians, poets, and other writers, as well as being the namesakes of various water- and aircraft. They are commemorated by festivals worldwide. Mayflies are especially important to fishing. Mayflies contribute to the provisioning services of ecosystems in that they are utilized as food by human cultures worldwide (having one of the highest protein contents of any edible insect), as laboratory organisms, and as a potential source of antitumor molecules. They provide regulatory services through their cleaning of freshwater. They provide many essential supporting services for ecosystems such as bioturbation, bioirrigation, decomposition, nutrition for many kinds of non-human animals, nutrient cycling and spiraling in freshwaters, nutrient cycling between aquatic and terrestrial systems, habitat for other organisms, and serving as indicators of ecosystem health. About 20% of mayfly species worldwide might have a threatened conservation status due to influences from pollution, invasive alien species, habitat loss and degradation, and climate change. Even mitigation of negative influences has benefits and tradeoffs, as, in several cases, sustainable energy production negatively impacts mayflies. [ABSTRACT FROM AUTHOR]

Aim: To develop a causal understanding of the drivers of Species distribution model (SDM) performance. Location: United Kingdom (UK). Methods: We measured the accuracy and variance of SDMs fitted for 518 species of invertebrate and plant in the UK. Our measure of variance reflects variation among replicate model fits, and taxon experts assessed model accuracy. Using directed acyclic graphs, we developed a causal model depicting plausible effects of explanatory variables (e.g. species' prevalence, sample size) on SDM accuracy and variance and quantified those effects using a multilevel piecewise path model. Results: According to our model, sample size and niche completeness (proportion of a species' niche covered by sampling) directly affect SDM accuracy and variance. Prevalence and range completeness have indirect effects mediated by sample size. Challenging conventional wisdom, we found that the effect of prevalence on SDM accuracy is positive. This reflects the facts that sample size has a positive effect on accuracy and larger sample sizes are possible for widespread species. It is possible, however, that the omission of an unobserved confounder biased this effect. Previous studies, which reported negative correlations between prevalence and SDM accuracy, conditioned on sample size. Main conclusions: Our model explicates the causal basis of previously reported correlations between SDM performance and species/data characteristics. It also suggests that niche completeness has similarly large effects on SDM accuracy and variance as sample size. Analysts should consider niche completeness, or proxies thereof, in addition to sample size when deciding whether modelling is worthwhile. [ABSTRACT FROM AUTHOR]

Background Rickettsia are intracellular bacteria best known as the causative agents of human and animal diseases. Although these medically important Rickettsia are often transmitted via haematophagous arthropods, other Rickettsia , such as those in the Torix group, appear to reside exclusively in invertebrates and protists with no secondary vertebrate host. Importantly, little is known about the diversity or host range of Torix group Rickettsia. Results This study describes the serendipitous discovery of Rickettsia amplicons in the Barcode of Life Data System (BOLD), a sequence database specifically designed for the curation of mitochondrial DNA barcodes. Of 184,585 barcode sequences analysed, Rickettsia is observed in ∼0.41% of barcode submissions and is more likely to be found than Wolbachia (0.17%). The Torix group of Rickettsia are shown to account for 95% of all unintended amplifications from the genus. A further targeted PCR screen of 1,612 individuals from 169 terrestrial and aquatic invertebrate species identified mostly Torix strains and supports the "aquatic hot spot" hypothesis for Torix infection. Furthermore, the analysis of 1,341 SRA deposits indicates that Torix infections represent a significant proportion of all Rickettsia symbioses found in arthropod genome projects. Conclusions This study supports a previous hypothesis that suggests that Torix Rickettsia are overrepresented in aquatic insects. In addition, multiple methods reveal further putative hot spots of Torix Rickettsia infection, including in phloem-feeding bugs, parasitoid wasps, spiders, and vectors of disease. The unknown host effects and transmission strategies of these endosymbionts make these newly discovered associations important to inform future directions of investigation involving the understudied Torix Rickettsia. [ABSTRACT FROM AUTHOR]