12 research outputs found
Systematic review of the effects of chemical insecticides on four common butterfly families
Safeguarding crop productivity by protecting crops from pest attacks entails the wide use of plant protection products that provide a quick, easy and cheap solution. The objective of this study is to understand the effects of insecticides used in agriculture on non-target butterflies, specifically on the families Lycaenidae, Nymphalidae, Hesperiidae, and Papilionidae. To achieve this goal, a formal systematic review was performed according to European Food Safety Authority (EFSA) guidelines, by entering a combination of keywords on 3 online databases. Three reviewers independently extracted information on study characteristics and quality. The main results were collected and grouped by the insecticide used, butterflies species and family, and endpoints. The output was valuable but heterogeneous as the endpoints and methodologies of the studies reviewed were different. Few experimental studies on the effects of insecticides on the most common butterfly families have been published. Naled and permethrin are the most commonly used insecticides in the experiments, whilst the target organisms of these studies are Vanessa cardui, Danaus plexippus, Heliconius charitonius, belonging to the Nymphalidae family, and Eumaeus atala, belonging to the Lycaenidae family; the effects were evaluated on all developmental stages, with special attention to the larval phase. This systematic review highlights the need for more studies on the effects of chemical insecticides on non-target Lepidoptera in light of their ecological importance and the extensive use of these chemical products
How do freshwater organisms cross the “dry ocean”? A review on passive dispersal and colonization processes with a special focus on temporary ponds
Lakes and ponds are scattered on Earth’s surface as islands in the ocean. The organisms inhabiting these ecosystems have thus developed strategies to pass the barrier represented by the surrounding land, disperse and colonise new environments. The evidences of a high potential for passive long-range dispersal of organisms producing resting stages inspired the idea that there were no real barriers to their actual dispersal, and that their distribution was only limited by the ecological characteristics of the available habitats. The development of genetic techniques allowed to criticise this view and revealed the existence of a more complex and diverse biological scenario governed by an assortment of historical and ecological factors. In this paper we review the literature related to the passive dispersal of organisms producing resting stages among inland lentic ecosystems, with special emphasis to temporary ponds, which represent “isolated” ecosystems both in space and in time, and are characterised by high levels of biological diversity. The existence of a sharp decoupling between “dispersal potential” and “actual establishment rates” is stressed, thus urging a definitive overcome of the so-called “Everything is Everywhere” hypothesis in order to gain a proper understanding of the biogeography and ecology of inland-water organisms
Diversity Arrays Technology (DArT) for Pan-Genomic Evolutionary Studies of Non-Model Organisms
Background: High-throughput tools for pan-genomic study, especially the DNA microarray platform, have sparked a remarkable increase in data production and enabled a shift in the scale at which biological investigation is possible. The use of microarrays to examine evolutionary relationships and processes, however, is predominantly restricted to model or near-model organisms.
Methodology/Principal Findings: This study explores the utility of Diversity Arrays Technology (DArT) in evolutionary studies of non-model organisms. DArT is a hybridization-based genotyping method that uses microarray technology to identify and type DNA polymorphism. Theoretically applicable to any organism (even one for which no prior genetic data are available), DArT has not yet been explored in exclusively wild sample sets, nor extensively examined in a phylogenetic framework. DArT recovered 1349 markers of largely low copy-number loci in two lineages of seed-free land plants: the diploid fern Asplenium viride and the haploid moss Garovaglia elegans. Direct sequencing of 148 of these DArT markers identified 30 putative loci including four routinely sequenced for evolutionary studies in plants. Phylogenetic analyses of DArT genotypes reveal phylogeographic and substrate specificity patterns in A. viride, a lack of phylogeographic pattern in Australian G. elegans, and additive variation in hybrid or mixed samples.
Conclusions/Significance: These results enable methodological recommendations including procedures for detecting and analysing DArT markers tailored specifically to evolutionary investigations and practical factors informing the decision to use DArT, and raise evolutionary hypotheses concerning substrate specificity and biogeographic patterns. Thus DArT is a demonstrably valuable addition to the set of existing molecular approaches used to infer biological phenomena such as adaptive radiations, population dynamics, hybridization, introgression, ecological differentiation and phylogeography
Taxonomy and evolution of the Convolvulus sabatius complex (Convolvulaceae)
A revision of the Convolvulus sabatius complex is presented and five taxa are now recognised. Convolvulus valentinus is
re-circumscribed to comprise only blue-flowered individuals. Yellow-flowered plants previously referred to this species
are transferred to C. supinus where they are recognised as a distinct variety: C. supinus var. melliflorus, comb nov.
Variation in intensity of flower colour, pubescence and leaf shape among blue-flowered C. valentinus is highly variable
within populations and in contrast to earlier treatments, no infraspecific taxa based on these traits are recognised. Despite
suggestions to the contrary, the delimitation of the cultivated ornamental C. sabatius and its two subspecies is
unproblematic. Molecular data from the chloroplast trnH-psbA region support the recircumscription of C. supinus and C.
valentinus and highlight the genetic distinctiveness of a disjunct Iberian population of the latter that merits further
investigation
Assessing the use of the mitochondrial COX1 marker for use in DNA barcoding of red algae (Rhodophyta)
The red algae, a remarkably diverse group of organisms, are difficult to identify using morphology alone. Following the proposal to use the mitochondrial cytochrome c oxidase subunit 1 (cox1) for DNA barcoding animals, we assessed the use of this, ne in the identification of red algae using 48 samples plus 31 sequences obtained from GenBank. The data set spanned six gene orders of red algae: the Bangiales, Ceramiales, Corallinales, Gigartinales, Gracilariales and Rhodymeniales. The results indicated that species could be discriminated. Intraspecific variation was between 0 and 4 bp over 539 bp analyzed except in Mastocarpus stellatus (0-14 bp) and Gracilaria gracilis (0-11 bp). Cryptic diversity was found in Bangia fuscopurpurea, Corallina officinalis, G. gracilis, M. stellatus, Porphyra leucosticta and P. umbilicalis. Interspecific variation across all taxa was between 28 and 148 bp, except for G. gracilis and M. stellatus. A comparison of cox1 with the plastid Rubisco spacer for Porphyra species revealed that it was a more sensitive marker in revealing incipient speciation and cryptic diversity. The cox1 gene has the potential to be used for DNA barcoding of red algae, although a good taxonomic foundation coupled with extensive sampling of taxa is essential for the development of an effective identification system
Could Europe Apply a Suitable Control Method for the Small Hive Beetle (Coleoptera: Nitidulidae)?
The European bee, Apis mellifera L. (Hymenoptera: Apidae), is a fundamental resource for the pollination of a great variety of botanical species used by humans for sustenance. Over the last few decades, bee colonies have become vulnerable to a new pest that has advanced beyond its native sub-Saharan territory: the small hive beetle, Aethina tumida Murray (Coleoptera: Nitidulidae). This currently presents a pressing problem in the United States and Australia, but it has also been recorded in Portugal and Italy and it is likely to spread in the rest of Europe too. This study represents a systematic review, based on EFSA guidelines, of the various control treatments for small hive beetles in order to identify the most effective methods as well as, those with no effects on bee colonies. The results show that the bulk of these studies were performed in the United States and that a number of treatments are suitable for the control of A. tumida, though some have negative effects on bees while others have low effectiveness or are ineffective. The best results are those with the entomopathogenic nematodes of the genus Steinernema and Heterorhabditis, but also with formic acid or diatomaceous earth. Various products containing insecticides have been effective, for example, Perizin (Bayer), GardStar (Y-Tex), CheckMite+ strips (Bayer), but Apithor (Apithor ) cannot be used in Europe because it contains Fipronil, which has been banned since 2013. Some common products like bleach and detergent have also been effective
The monophyly and evolution of Cynara L. (Asteraceae) sensu lato: evidence from the Internal Transcribed Spacer region of nrDNA
The monophyly and evolution of Cynara was investigated using ITS sequence data. Parsimony analysis supports the monophyly of Cynara sensu lato, i.e. including the distinctive taxa C. humilis and C. tournefortii. This contradicts the recent decision to create a new monotypic genus Arcyna for C. tournefortii. A hypothesised close relationship between C. tournefortii and Silybum Adans. is also refuted. Four of the five species of Cynara, for which multiple accessions were sequenced, were shown to be monophyletic but C. baetica was found to be non-monophyletic. Free energy estimates for ITS1 secondary structure and conservation of the 5.8S region suggest that this is not due to the occurrence of pseudogenes. Hybridisation is a plausible explanation but evidence for the likely parents involved in such an event is inconclusive
Molecular and morphological evidence for hybridization between endemic Canary Island Convolvulus
Morphological data and molecular data from the chloroplast trnH-psbA region and nuclear ribosomal ITS region are used to test the hypothesis that the problematic Canary Island endemic Convolvulus floridus var. virgatus is a hybrid between the endemic species C. floridus and C. scoparius. Analysis of mean leaf length and width of 58 individuals indicates that accessions referable to C. floridus var. virgatus are intermediate between the parental taxa in leaf dimensions. Direct sequencing of the ITS region of C. scoparius and C. floridus revealed two species-specific ribotypes distinguished by 10 base differences. Examination of ITS chromatograms for putative hybrids revealed polymorphisms at those sites that are diagnostic between species in all except one putative hybrid. Morphological intermediacy and ITS additivity therefore support the hybrid status of C. floridus var. virgatus. An analysis of intraindividual ITS variation confirmed the co-occurrence of both parental ribotypes in putative hybrids and demonstrated that some hybrid individuals contained chimaeric ITS types. It is proposed that chimaeric ITS types are the result of recombination following backcrossing. Sequencing of the trnH-psbA region revealed four haplotypes. Three were, for the most part, confined to C. floridus and putative hybrids although one C. scoparius accession was also found to share this haplotype. The remaining haploype was only found in C. scoparius and putative hybrid accessions. Patterns of haplotype distribution between parental and hybrid accessions suggest multiple, bidirectional hybridization events between C. floridus and C. scoparius. The nomenclature of the hybrid is discussed and the necessary new name C. × despreauxii is proposed. © 2007 The Linnean Society of London