Identification of sawflies and horntails (Hymenoptera, 'Symphyta') through DNA barcodes: successes and caveats.

The 'Symphyta' is a paraphyletic assemblage at the base of the order Hymenoptera, comprising 14 families and about 8750 species. All have phytophagous larvae, except for the Orussidae, which are parasitoids. This study presents and evaluates the results of DNA barcoding of approximately 5360 specimens of 'Symphyta', mainly adults, and 4362 sequences covering 1037 species were deemed of suitable quality for inclusion in the analysis.

DNA barcoding reveals diversity of Hymenoptera and the dominance of parasitoids in a sub-arctic environment.

Background: Insect diversity typically declines with increasing latitude, but previous studies have shown conflicting latitude-richness gradients for some hymenopteran parasitoids. However, historical estimates of insect diversity and species richness can be difficult to confirm or compare, because they may be based upon dissimilar methods. As a proxy for species identification, we used DNA barcoding to identify molecular operational taxonomic units (MOTUs) for 7870 Hymenoptera specimens collected near Churchill, Manitoba, from 2004 through 2010.

Wolbachia and DNA barcoding insects: patterns, potential, and problems.

Wolbachia is a genus of bacterial endosymbionts that impacts the breeding systems of their hosts. Wolbachia can confuse the patterns of mitochondrial variation, including DNA barcodes, because it influences the pathways through which mitochondria are inherited. We examined the extent to which these endosymbionts are detected in routine DNA barcoding, assessed their impact upon the insect sequence divergence and identification accuracy, and considered the variation present in Wolbachia COI.

The endosymbiont community as taxonomic character: a novel approach to resolving the Bemisia tabaci complex.

In this issue of Molecular Ecology, Gueguen et al. (2010) describe their novel approach to resolving cryptic genetic diversity in the Bemisia tabaci complex (Hemiptera: Aleyrodidae.) Complexes of cryptic species present a challenge to both morphological and molecular taxonomy – the former presumed, as shared morphology normally defines species as cryptic, but the latter also problematic when host DNA sequence data is either inconclusive or unaccompanied by independent evidence.

The mushroom habitat as an ecological arena for global exchange of Wolbachia.

Wolbachia infect a variety of arthropod and nematode hosts, but in arthropods, host phylogenetic relationships are usually poor predictors of strain similarity. This suggests that new infections are often established by horizontal transmission. To gain insight into the factors affecting the probability of horizontal transmission among host species, we ask how host phylogeny, geographical distribution and ecology affect patterns of Wolbachia strain similarity.

Accelerated microevolution in an outer membrane protein (OMP) of the intracellular bacteria Wolbachia.

Background: Outer membrane proteins (OMPs) of Gram-negative bacteria are key players in the biology of bacterial-host interactions. However, while considerable attention has been given to OMPs of vertebrate pathogens, relatively little is known about the role of these proteins in bacteria that primarily infect invertebrates. One such OMP is found in the intracellular bacteria Wolbachia, which are widespread symbionts of arthropods and filarial nematodes.

Association between Wolbachia and Spiroplasma within Drosophila neotestacea: an emerging symbiotic mutualism?

Interspecific mutualism can evolve when specific lineages of different species tend to be associated with each other from one generation to the next. Different maternally transmitted endosymbionts occurring within the same cytoplasmic lineage fulfil this requirement. Drosophila neotestacea is infected with maternally transmitted Wolbachia and Spiroplasma, which are cotransmitted at high frequency in natural populations.

Specialization and geographic isolation among Wolbachia symbionts from ants and lycaenid butterflies.

Wolbachia are the most prevalent and influential bacteria described among the insects to date. But despite their significance, we lack an understanding of their evolutionary histories. To describe the evolution of symbioses between Wolbachia and their hosts, we surveyed global collections of two diverse families of insects, the ants and lycaenid butterflies.

Insight into the routes of Wolbachia invasion: high levels of horizontal transfer in the spider genus Agelenopsis revealed by Wolbachia strain and mitochondrial DNA diversity.

The pandemic distribution of Wolbachia (alpha-proteobacteria) across arthropods is largely due to the ability of these maternally inherited endosymbionts to successfully shift hosts across species boundaries. Yet it remains unclear whether Wolbachia has preferential routes of transfer among species. Here, we examined populations of eight species of the North American funnel-web spider genus Agelenopsis to evaluate whether Wolbachia show evidence for host specificity and the relative contribution of horizontal vs.

Functionally reproductive diploid and haploid males in an inbreeding hymenopteran with complementary sex determination.

It has become a matter of orthodoxy that among wasps, ants, bees, and other insects in the order Hymenoptera, only uniparental haploid males that arise from unfertilized eggs are capable of reproduction. This idea is of interest because the best understood and perhaps most widespread sex determination system among these insects [known as single locus complementary sex determination (sl-CSD)] does not depend on ploidy alone and, paradoxically, consistently results in small numbers of diploid biparental males. To date, the reproductive potential of diploid males has been studied in 13 of the perhaps 200,000 hymenopterans world-wide; in each of these instances, the diploid males are genetic dead ends because they are inviable or sterile.

Inbreeding in a natural population of Euodynerus foraminatus (Hymenoptera: Vespidae), a solitary wasp with single-locus complementary sex determination.

The solitary wasp Euodynerus foraminatus has single-locus complementary sex determination (sl-CSD), which is normally incompatible with inbreeding because it increases the production of sterile or inviable diploid males. Previous field observations of E. foraminatus have suggested that high levels of sibling mating are present in this species.