Widespread losses of pollinating insects in Britain.
Ontology highlight
ABSTRACT:
SUBMITTER: Powney GD
PROVIDER: S-EPMC6435717 | biostudies-literature | 2019 Mar
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:The potential for infectious pathogens to spillover and emerge from managed populations to wildlife communities is poorly understood, but ecological, evolutionary and anthropogenic factors are all likely to influence the initial exposure and subsequent infection, spread and impact of disease. Fast-evolving RNA viruses, known to cause severe colony losses in managed honeybee populations, deserve particular attention for their propensity to jump between host species and thus threaten ecologically and economically important wild pollinator communities. We review the literature on pollinator viruses to identify biological and anthropogenic drivers of disease emergence, highlight gaps in the literature, and discuss potential management strategies. We provide evidence that many wild pollinator species are exposed to viruses from commercial species, resulting in multiple spillover events. However, it is not clear whether species become infected as a result of spillover or whether transmission is occurring within these wild populations. Ecological traits of pollinating insects, such as overlapping ranges, niches and behaviours, clearly promote cross-species transmission of RNA viruses. Moreover, we conclude that the social behaviour and phylogenetic relatedness of social pollinators further facilitate within- and between-host transmission, leaving these species particularly vulnerable to emerging diseases. We argue that the commercial use of pollinators is a key driver of disease emergence in these beneficial insects and that this must be addressed by management and policy. Synthesis and applications. There are important knowledge gaps, ranging from disease distribution and prevalence, to pathogen life history and virulence, to the impacts of disease emergence, which need to be addressed as research priorities. It is clear that avoiding anthropogenic pathogen spillover is crucial to preventing and managing disease emergence in pollinators, with far-reaching effects on our food security, ecosystem services and biodiversity. We argue that it is crucial to prevent the introduction of diseased pollinators into natural environments, which can be achieved through improved monitoring and management practices.
| S-EPMC4415536 | biostudies-literature
Project description:BackgroundThe increasing number of sequenced insect and vertebrate genomes of variable divergence enables refined comparative analyses to quantify the major modes of animal genome evolution and allows tracing of gene genealogy (orthology) and pinpointing of gene extinctions (losses), which can reveal lineage-specific traits.ResultsTo consistently quantify losses of orthologous groups of genes, we compared the gene repertoires of five vertebrates and five insects, including honeybee and Tribolium beetle, that represent insect orders outside the previously sequenced Diptera. We found hundreds of lost Urbilateria genes in each of the lineages and assessed their phylogenetic origin. The rate of losses correlates well with the species' rates of molecular evolution and radiation times, without distinction between insects and vertebrates, indicating their stochastic nature. Remarkably, this extends to the universal single-copy orthologs, losses of dozens of which have been tolerated in each species. Nevertheless, the propensity for loss differs substantially among genes, where roughly 20% of the orthologs have an 8-fold higher chance of becoming extinct. Extrapolation of our data also suggests that the Urbilateria genome contained more than 7,000 genes.ConclusionOur results indicate that the seemingly higher number of observed gene losses in insects can be explained by their two- to three-fold higher evolutionary rate. Despite the profound effect of many losses on cellular machinery, overall, they seem to be guided by neutral evolution.
| S-EPMC2258195 | biostudies-literature
Project description:Body size is an integral functional trait that underlies pollination-related ecological processes, yet it is often impractical to measure directly. Allometric scaling laws have been used to overcome this problem. However, most existing models rely upon small sample sizes, geographically restricted sampling and have limited applicability for non-bee taxa. Allometric models that consider biogeography, phylogenetic relatedness, and intraspecific variation are urgently required to ensure greater accuracy. We measured body size as dry weight and intertegular distance (ITD) of 391 bee species (4,035 specimens) and 103 hoverfly species (399 specimens) across four biogeographic regions: Australia, Europe, North America, and South America. We updated existing models within a Bayesian mixed-model framework to test the power of ITD to predict interspecific variation in pollinator dry weight in interaction with different co-variates: phylogeny or taxonomy, sexual dimorphism, and biogeographic region. In addition, we used ordinary least squares regression to assess intraspecific dry weight ~ ITD relationships for ten bees and five hoverfly species. Including co-variates led to more robust interspecific body size predictions for both bees and hoverflies relative to models with the ITD alone. In contrast, at the intraspecific level, our results demonstrate that the ITD is an inconsistent predictor of body size for bees and hoverflies. The use of allometric scaling laws to estimate body size is more suitable for interspecific comparative analyses than assessing intraspecific variation. Collectively, these models form the basis of the dynamic R package, "pollimetry," which provides a comprehensive resource for allometric pollination research worldwide.
| S-EPMC6392396 | biostudies-literature
Project description:The vertebrate vomeronasal system (VNS) detects intraspecific pheromones and environmental odorants. We sequenced segments of the gene encoding Trpc2, an ion channel crucial for vomeronasal signal transduction, in 11 species that represent all main basal lineages of Yinpterochiroptera, one of the two suborders of the order Chiroptera (bats). Our sequences show that Trpc2 is a pseudogene in each of the 11 bats, suggesting that all yinpterochiropterans lack vomeronasal sensitivity. The Trpc2 sequences from four species of Yangochiroptera, the other suborder of bats, suggest vomeronasal insensitivity in some but not all yangochiropterans. These results, together with the available morphological data from the bat VNS, strongly suggest multiple and widespread losses of vomeronasal signal transduction and sensitivity in bats. Future scrutiny of the specific functions of the VNS in the few bats that still retain the VNS may help explain why it is dispensable in most bats.
| S-EPMC3108603 | biostudies-literature
Project description:One of the defining features of the Anthropocene is eroding ecosystem services, decreases in biodiversity, and overall reductions in the abundance of once-common organisms, including many insects that play innumerable roles in natural communities and agricultural systems that support human society. It is now clear that the preservation of insects cannot rely solely on the legal protection of natural areas far removed from the densest areas of human habitation. Instead, a critical challenge moving forward is to intelligently manage areas that include intensively farmed landscapes, such as the Central Valley of California. Here we attempt to meet this challenge with a tool for modeling landscape connectivity for insects (with pollinators in particular in mind) that builds on available information including lethality of pesticides and expert opinion on insect movement. Despite the massive fragmentation of the Central Valley, we find that connectivity is possible, especially utilizing the restoration or improvement of agricultural margins, which (in their summed area) exceed natural areas. Our modeling approach is flexible and can be used to address a wide range of questions regarding both changes in land cover as well as changes in pesticide application rates. Finally, we highlight key steps that could be taken moving forward and the great many knowledge gaps that could be addressed in the field to improve future iterations of our modeling approach.
| S-EPMC9916620 | biostudies-literature
Project description:Condensins play a crucial role in the organization of genetic material by compacting and disentangling chromosomes. Based on studies in a few model organisms, the condensins I and II complexes are considered to have distinct functions, with the condensin II complex playing a role in meiosis and somatic pairing of homologous chromosomes in Drosophila. Intriguingly, the Cap-G2 subunit of condensin II is absent in Drosophila melanogaster, and this loss may be related to the high levels of chromosome pairing seen in flies. Here, we find that all three non-SMC subunits of condensin II (Cap-G2, Cap-D3, and Cap-H2) have been repeatedly and independently lost in taxa representing multiple insect orders, with some taxa lacking all three. We also find that all non-Dipteran insects display near-uniform low-pairing levels regardless of their condensin II complex composition, suggesting that some key aspects of genome organization are robust to condensin II subunit losses. Finally, we observe consistent signatures of positive selection in condensin subunits across flies and mammals. These findings suggest that these ancient complexes are far more evolutionarily labile than previously suspected, and are at the crossroads of several forms of genomic conflicts. Our results raise fundamental questions about the specific functions of the two condensin complexes in taxa that have experienced subunit losses, and open the door to further investigations to elucidate the diversity of molecular mechanisms that underlie genome organization across various life forms.
| S-EPMC6759200 | biostudies-literature
Project description:Loss of suitable seminatural habitats and homogenization of crop types have led to the population decline of pollinating insects in farmland. As these insects support crop production, many practical efforts aim to sustain pollinator diversity which is especially challenging in intensively managed and homogeneous farmland. However, there are ongoing changes of the farmland toward its multifunctionality that includes, for example, wind farm development. Windmills are often built within crops; thus, we examined if the noncropped area around windmills can be valuable habitats for wild plants and pollinating insects: bees, butterflies, and flies. Species richness, abundances, and species diversity index of plants and pollinators around windmills were similar to those found in grassland patches (a typical habitat for these insects) and higher than in the adjacent crops. Pollinator diversity index and species richness at windmills increased with the distance to the nearest grassland patch and windmill. The population sizes of pollinating insects were also positively associated with plant diversity. Particular groups of pollinators showed specific habitat associations: bees occurred mostly at windmills, butterflies were highly associated with grasslands, while flies occurred in a similar number at windmill and on grasslands. Since windmills are frequently built within extensive homogeneous fields, thus, they introduce pollination services into the interior of cropped areas, contrary to field margins, road verges, or seminatural grasslands. Thus, although the development of wind farms has various negative environmental consequences, they can be alleviated by the increase of the local population size and diversity of wild plants and pollinating insects at windmills.
| S-EPMC5846843 | biostudies-literature
Project description:The evolutionary success of hymenopteran insects has been associated with complex physiological and behavioral defense mechanisms against pathogens and parasites. Among these strategies are symbiotic associations between Hymenoptera and antibiotic-producing Actinobacteria, which provide protection to insect hosts. Herein, we examine associations between culturable Actinobacteria and 29 species of tropical hymenopteran insects that span five families, including Apidae (bees), Vespidae (wasps), and Formicidae (ants). In total, 197 Actinobacteria isolates were obtained from 22 of the 29 different insect species sampled. Through 16S rRNA gene sequences of 161 isolates, we show that 91% of the symbionts correspond to members of the genus Streptomyces with less common isolates belonging to Pseudonocardia and Amycolatopsis. Electron microscopy revealed the presence of filamentous bacteria with Streptomyces morphology in brood chambers of two different species of the eusocial wasps. Four fungal strains in the family Ophiocordycipitacea (Hypocreales) known to be specialized insect parasites were also isolated. Bioassay challenges between the Actinobacteria and their possible targeted pathogenic antagonist (both obtained from the same insect at the genus or species level) provide evidence that different Actinobacteria isolates produced antifungal activity, supporting the hypothesis of a defensive association between the insects and these microbe species. Finally, phylogenetic analysis of 16S rRNA and gyrB demonstrate the presence of five Streptomyces lineages associated with a broad range of insect species. Particularly our Clade I is of much interest as it is composed of one 16S rRNA phylotype repeatedly isolated from different insect groups in our sample. This phylotype corresponds to a previously described lineage of host-associated Streptomyces. These results suggest Streptomyces Clade I is a Hymenoptera host-associated lineage spanning several new insect taxa and ranging from the American temperate to the Neotropical region. Our work thus provides important insights into the widespread distribution of Actinobacteria and hymenopteran insects associations, while also pointing at novel resources that could be targeted for the discovery of active natural products with great potential in medical and biotechnological applications.
| S-EPMC5651009 | biostudies-literature
Project description:Insect pests are one of the factors that most impact plant yield. The magnitude of the losses and the spatiotemporal pest distribution in crops is a result of their interactions with the environment. Therefore, the understanding of the causes of production losses and the pest spatial patterns is important for the development of suitable sampling plans and pest management programs. Thus, this study aimed to quantify grain losses caused by insects and to determine the spatial distribution pattern of arthropod pest species in Bt and non-Bt corn. The prevailing insect pests in the corn ears were the earworm and fall armyworm caterpillars (Helicoverpa spp. and Spodoptera frugiperda), the cornsilk fly (Euxesta spp.), the maize weevil (Sitophilus zeamais), and the square-necked grain beetle (Cathartus quadricollis). The non-Bt corn was more attacked by the caterpillars and the weevil, while Bt corn was more affected by the cornsilk fly Euxesta spp. Spatial dependence was significant for the damage caused by the caterpillars, the grain beetle and the maize weevil in both the Bt and non-Bt corn genotypes. The range of the damage caused by the insects was between 9.0-9.7 m for the caterpillars, 6.9-12.20 m for the cornsilk fly, 10.7-80.4 m for the square-necked grain beetle, and 51.9-170.7 m for the maize weevil. The pattern of the spatial distribution of pest damage in both corn genotypes (i.e., Bt and non-Bt corn) was similar with a prevalence of moderate to strong spatial dependence and aggregate damage distribution. The plants near to the sampling points exhibited injury and infestation levels similar to those of the sampled plants.
| S-EPMC6086412 | biostudies-literature
Project description:Bees are a key component of biodiversity as they ensure a crucial ecosystem service: pollination. This ecosystem service is nowadays threatened, because bees suffer from agricultural intensification. Yet, bees rarely benefit from the measures established to promote biodiversity in farmland, such as agri-environment schemes (AES). We experimentally tested if the spatio-temporal modification of mowing regimes within extensively managed hay meadows, a widespread AES, can promote bees. We applied a randomized block design, replicated 12 times across the Swiss lowlands, that consisted of three different mowing treatments: 1) first cut not before 15 June (conventional regime for meadows within Swiss AES); 2) first cut not before 15 June, as treatment 1 but with 15% of area left uncut serving as a refuge; 3) first cut not before 15 July. Bees were collected with pan traps, twice during the vegetation season (before and after mowing). Wild bee abundance and species richness significantly increased in meadows where uncut refuges were left, in comparison to meadows without refuges: there was both an immediate (within year) and cumulative (from one year to the following) positive effect of the uncut refuge treatment. An immediate positive effect of delayed mowing was also evidenced in both wild bees and honey bees. Conventional AES could easily accommodate such a simple management prescription that promotes farmland biodiversity and is likely to enhance pollination services.
| S-EPMC3887108 | biostudies-literature