The use of unique DNA sequences as a method for taxonomic identification is no longer fundamentally controversial, even though debate continues on the best markers, methods, and technology to use. Although both existing databanks such as GenBank and BOLD, as well as reference taxonomies, are imperfect, in best case scenarios “barcodes” (whether single or multiple, organelle or nuclear, loci) clearly are an increasingly fast and inexpensive method of identification, especially as compared to manual identification of unknowns by increasingly rare expert taxonomists. Because most species on Earth are undescribed, a complete reference database at the species level is impractical in the near term. The question therefore arises whether unidentified species can, using DNA barcodes, be accurately assigned to more inclusive groups such as genera and families—taxonomic ranks of putatively monophyletic groups for which the global inventory is more complete and stable. We used a carefully chosen test library of CO1 sequences from 49 families, 313 genera, and 816 species of spiders to assess the accuracy of genus and family-level assignment. We used BLAST queries of each sequence against the entire library and got the top ten hits. The percent sequence identity was reported from these hits (PIdent, range 75–100%). Accurate assignment of higher taxa (PIdent above which errors totaled less than 5%) occurred for genera at PIdent values >95 and families at PIdent values ≥ 91, suggesting these as heuristic thresholds for accurate generic and familial identifications in spiders. Accuracy of identification increases with numbers of species/genus and genera/family in the library; above five genera per family and fifteen species per genus all higher taxon assignments were correct. We propose that using percent sequence identity between conventional barcode sequences may be a feasible and reasonably accurate method to identify animals to family/genus. However, the quality of the underlying database impacts accuracy of results; many outliers in our dataset could be attributed to taxonomic and/or sequencing errors in BOLD and GenBank. It seems that an accurate and complete reference library of families and genera of lifecouldprovide accurate higher level taxonomic identifications cheaply and accessibly, within years rather than decades.

Recent declines in insect abundances, especially populations of wild pollinators, pose a threat to many natural and agricultural ecosystems. Traditional species monitoring relies on morphological character identification and is inadequate for efficient and standardized surveys. DNA barcoding has become a standard approach for molecular identification of organisms, aiming to overcome the shortcomings of traditional biodiversity monitoring. However, its efficacy depends on the completeness of reference databases. Large DNA barcoding efforts are (almost entirely) lacking in many European countries and such patchy data limit Europe‐wide analyses of precisely how to apply DNA barcoding in wild bee identification. Here, we advance towards an effective molecular identification of European wild bees. We conducted a high‐effort survey of wild bees at the junction of central and southern Europe and DNA barcoded all collected morphospecies. For global analyses, we complemented our DNA barcode dataset with all relevant European species and conducted global analyses of species delimitation, general and genus‐specific barcoding gaps and examined the error rate in DNA data repositories. We found that (i) a sixth of all specimens from Slovenia could not be reliably identified, (ii) species delimitation methods show numerous systematic discrepancies, (iii) there is no general barcoding gap across all bees and (iv) the barcoding gap is genus specific, but only after curating for errors in DNA data repositories. Intense sampling and barcoding efforts in underrepresented regions and strict curation of DNA barcode repositories are needed to enhance the use of DNA barcoding for the identification of wild bees.

Aim: A wholistic biogeographical reconstruction should combine a phylogeny with specifics of organismal biology, plate tectonics and consequent probabilities of historic dispersal events. Here, we demonstrate this approach by reconstructing the geographical origin and sequence of intercontinental colonization of the golden orbweaving spiders, a global clade. We test two alternative hypotheses about their ancestral range. Due to the highest contemporary species diversity in Africa, the ‘Out of Africa’ hypothesis predicts the Afrotropics as their most likely ancestral area. The alternative, ‘Out of West Burma’ hypothesis aims to explain a Burmese amber fossil as stem nephilid. Because the West Burma block probably detached from Australia, then rafted towards Laurasia, either on its own or with India, this hypothesis predicts either Australasia or Indomalaya (or both) as the ancestral area.Location: Worldwide.Taxon: Golden orbweaving spiders, family Nephilidae.Methods: We construct an expanded phylogeny of nephilid spiders and apply RASP (Reconstruct Ancestral State in Phylogenies) to infer their global biogeographical history. We fit the data to six integrated biogeographical models: DEC, DIVALIKE, BAYAREALIKE and their +j variants. We fine‐tune the analysis by evaluating varying probabilities of dispersal between geographical areas throughout the clade's evolutionary history. We use the physical distance between the areas as a proxy for dispersal probabilities, thus accounting for plate tectonics.Results: The best supported model reconstructs both Australasia and Indomalaya as ancestral area. In several parts of the phylogeny, these areas persist for the estimated 130‐million‐year evolutionary history. However, numerous intercontinental shifts in nephilid biogeographical history are also inferred. Since nephilid origins are clearly Gondwanan, our study supports the interpretations that Burmese amber contains Gondwanan biota.Main conclusions: These results are consistent with the Out of West Burma hypothesis but reject the Out of Africa hypothesis. That certain clades persist in their ancestral ranges while others may shift continents aligns well with the known nephilid biology. Our methodological approach that assesses organismal specific dispersal probabilities through concrete distances measured though time slices of the Earth's history can be applied to biogeographical reconstruction of any lineage.