DNA barcoding of Austrian snow scorpionflies (Mecoptera, Boreidae) reveals potential cryptic diversity in Boreus westwoodi

Lukas Zangl; Elisabeth Glatzhofer; Raphael Schmid; Susanne Randolf; Stephan Koblmüller

doi:10.7717/peerj.11424

DNA barcoding of Austrian snow scorpionflies (Mecoptera, Boreidae) reveals potential cryptic diversity in Boreus westwoodi

PeerJ. 2021 May 14:9:e11424. doi: 10.7717/peerj.11424. eCollection 2021.

Authors

Lukas Zangl^{1

2}, Elisabeth Glatzhofer¹, Raphael Schmid¹, Susanne Randolf³, Stephan Koblmüller¹

Affiliations

¹ Institute of Biology, University of Graz, Graz, Styria, Austria.
² Universalmuseum Joanneum, Studienzentrum Naturkunde, Graz, Styria, Austria.
³ Natural History Museum Vienna, Vienna, Vienna, Austria.

Abstract

Background: Snow scorpionflies (genus Boreus) belong to a family of Mecoptera, Boreidae, that has been vastly neglected by entomological researchers due to their shift in seasonality to the winter months. Their activity during this time is regarded as a strategy for predator avoidance and regular sightings on snow fields suggest that this also facilitates dispersal. However, many aspects about snow scorpionflies, especially systematics, taxonomy, distribution of species, phylogenetics and phylogeography have remained fairly unexplored until today. In this study, we fill some of these gaps by generating a reference DNA barcode database for Austrian snow scorpionflies in the frame of the Austrian Barcode of Life initiative and by characterising morphological diversity in the study region.

Methods: Initial species assignment of all 67 specimens was based on male morphological characters previously reported to differ between Boreus species and, for females, the shape of the ovipositor. DNA barcoding of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene was carried out for all 67 samples and served as a basis for BIN assignment, genetic distance calculations, as well as alternative species delimitation analyses (ABGD, GMYC, bGMYC, bPTP) and a statistical parsimony network to infer phylogenetic relationships among individual samples/sampling sites.

Results: Morphological investigations suggested the presence of both Boreus hyemalis and Boreus westwoodi in Austria. DNA barcoding also separated the two species, but resulted in several divergent clades, the paraphyly of B. westwoodi in Austria, and high levels of phylogeographic structure on a small geographic scale. Even though the different molecular species delimitation methods disagreed on the exact number of species, they unequivocally suggested the presence of more than the traditionally recognized two Boreus species in Austria, thus indicating potential cryptic species within the genus Boreus in general and especially in B. westwoodi.

Keywords: Boreidae; DNA barcoding; Entomology; Morphology; Species delimiation.

Grants and funding

This research was funded by the Austrian Federal Ministry of Science, Research and Economy in the frame of an ABOL associated project within the framework of the “Hochschulraum-Strukturmittel” Funds. Financial support was also provided by the University of Graz for covering the costs for open access publication. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.