Revealing the hyperdiverse mite fauna of subarctic Canada through DNA barcoding

Abstract

Although mites are one of the most abundant and diverse groups of arthropods, they are rarely targeted for detailed biodiversity surveys due to taxonomic constraints. We address this gap through DNA barcoding, evaluating acarine diversity at Churchill, Manitoba, a site on the tundra-taiga transition. Barcode analysis of 6279 specimens revealed nearly 900 presumptive species of mites with high species turnover between substrates and between forested and non-forested sites. Accumulation curves have not reached an asymptote for any of the three mite orders investigated, and estimates suggest that more than 1200 species of Acari occur at this locality. The coupling of DNA barcode results with taxonomic assignments revealed that Trombidiformes compose 49% of the fauna, a larger fraction than expected based on prior studies. This investigation demonstrates the efficacy of DNA barcoding in facilitating biodiversity assessments of hyperdiverse taxa.

Figure 1. Sampling locations at Churchill.

Maps depict a) the location of Churchill in Canada, and b) all sample locations along with specific sampling sites in the Churchill region.

Figure 2. Bin accumulation curves.

Curves represent a) the overall dataset, with 899 BINs from 6279 samples, and b) curves for each order - Trombidiformes (437 BINs, n = 1933), Mesostigmata (135 BINs, n = 849), and Sarcoptiformes (327 BINs, n = 3497).

Figure 3. Cluster dendrograms showing the similarity of species assemblages for three mite orders among 10 sites in (F) and non-forested (N) settings.

Figure 4. Cluster dendrograms of showing the similarity of species assemblages for three mite orders among 8 substrates.

Figure 5. BIN accumulation curves for 5 families of Mesostigmata.

Figure 6. BIN accumulation curves for 11 families of Sarcoptiformes.

Figure 7. BIN accumulation curves for 10 families of Trombidiformes.