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

Abstract

BackgroundInsect 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.ResultsWe resolved 1630 MOTUs for this collection, of which 75% (1228) were ichneumonoids (Ichneumonidae + Braconidae) and 91% (1484) were parasitoids. We estimate the total number of Hymenoptera MOTUs in this region at 2624-2840.ConclusionsThe diversity of parasitoids in this sub-Arctic environment implies a high diversity of potential host species throughout the same range. We discuss these results in the contexts of resolving interspecific interactions that may include cryptic species, and developing reproducible methods to estimate and compare species richness across sites and between surveys, especially when morphological specialists are not available to identify every specimen.

Diversity of parasitoid and parasitic wasps across a latitudinal gradient: Using public DNA records to work within a taxonomic impediment

“…Indeed, in some cases where integrative taxonomic analyses that included DNA and morphological analyses were conducted coincidentally, it was found that barcodes alone would have recognized more than 97% of the species in the studies (Fernandez-Triana et al 2011). Furthermore, because the data are public such analyses are directly available to interested taxonomists in the future (Stahlhut et al 2013). …”

“…Upon collection, all specimens were preserved in 95% ethanol for sorting and DNA extraction. Specimens for each locality were selected randomly from traps for barcoding as described in Stahlhut et al (2013). DNA was extracted and sequences generated using standard methods detailed elsewhere (Smith et al 2006(Smith et al , 2007(Smith et al , 2008.…”

“…The use of operational taxonomic units (BINs) has been shown to be a rapid and effective method for species identification for many hymenopteran communities (Smith et al 2005(Smith et al , 2008Quicke et al 2012;Veijalainen et al 2012;Stahlhut et al 2013). Although BINs are not necessarily coincident with species boundaries, they display similar patterns in richness and turnover that can be helpful in short-term studies (Smith et al 2005 and in examining diversity patterns for species within the taxonomic impediment (Smith et al 2006(Smith et al , 2007(Smith et al , 2008.…”

Contributions to the study of the Holarctic fauna of Microgastrinae (Hymenoptera, Braconidae). I. Introduction and first results of transatlantic comparisons

“…Alaska, Manitoba, Nunavut, and Yukon Territory) and may reflect an increase in the availability of material recently collected in arctic and sub-arctic localities of North America (e.g., Fernández-Triana et al 2011;Stahlhut et al 2013). Other new records fill gaps in the known distribution of species.…”

Contribution of DNA barcoding to the study of the bees (Hymenoptera: Apoidea) of Canada: progress to date

“…For North America, and Canada in particular, several DNA barcoding projects have been undertaken for pollinators (e.g., Sheffield et al 2009;Hebert and Landry 2010;Hebert and Humble 2011;Zahiri et al 2014Zahiri et al , 2017, and many other taxa. These DNA barcode libraries can assist traditional morphological taxonomy by allowing identification of life stages for which keys are not available and/or taxonomy is more difficult (e.g., Slowik and Blagoev 2012), associating sexes (e.g., Sheffield et al 2011b), and in studies assessing biological diversity within regional (e.g., Sheffield et al 2009) and poorly studied habitatspecific biotas (e.g., Smith et al 2005Smith et al , 2009Stahlhut et al 2013). DNA barcode sequences (i.e., cytochrome c oxidase subunit I (COI)) and other genetic sequences themselves also contribute to molecular systematics; combining the DNA barcode gene with a single nuclear gene has proven useful for accurate, node-dated phylogenies for bees (Trunz et al 2016).…”