New Light on Historical Specimens Reveals a New Species of Ladybird (Coleoptera: Coccinellidae): Morphological, Museomic, and Phylogenetic Analyses

Abstract

Natural history collections house an important source of genetic data from yet unexplored biological diversity. Molecular data from museum specimens remain underexploited, which is mainly due to the degradation of DNA from specimens over time. However, Next-Generation Sequencing (NGS) technology can now be used to sequence “old” specimens. Indeed, many of these specimens are unique samples of nomenclatural types and can be crucial for resolving systematic or biogeographic scientific questions. Two ladybird beetle specimens from Patagonia corresponding to a new species of the genus Eriopis Mulsant were found in the collections of the Muséum national d’Histoire naturelle (MNHN), Paris. Here, we describe Eriopis patagonia Salazar, sp. nov. Total DNA of one of the two specimens was sequenced by NGS using a paired-end Illumina approach. We reconstruct and characterize the mitochondrial genome of this species (16,194 bp). Then, the protein-coding genes (PCGs) and ribosomal RNAs (rRNAs) were used to infer by maximum likelihood and Bayesian Inference the phylogenetic position of E. patagonia among 27 representatives of Coccinellidae. Phylogenetic analysis confirmed the position of Eriopis as sister group to Cycloneda Crotch. Hence, we highlight the high potential of sequencing technology for extracting molecular information from old specimens, which are used here for the systematic study of a genus, while demonstrating the importance of preserving biological collections.

A New Species of Scymnus (Coleoptera, Coccinellidae) from Pakistan with Mitochondrial Genome and Its Phylogenetic Implications

“…The large ribosomal RNA (16S rRNA) of Scymnus (Pullus) cardi is 1276 bp in size, with an A + T content of 82%, and its small ribosomal RNA (12S rRNA) is 793 bp, with an A + T content of 82.6% (Tables S1 and S2 and Figure 5). The two rRNA genes are located between tRNA-Leu1 and tRNA-Val and tRNA-Val and the control region, meaning that i resembles the mitogenome of previously studied ladybird beetles [59,62,65].…”

“…The AT skew and GC skew of 13 PCGs in S. (P.) cardi range from 0.26 (ND1) to −0.13 (ND3) and −0.05 (COX1) to −0.38 (ND6). S1), which are observed in the mitogenomes of beetles [59,62,75].…”

“…The total length of the 13 PCGs of Scymnus (Pullus) cardi is 11,060 bp and begins with the typical mitogenome codon ATN (N represents C, G, and T), except for the ND2 gene with AAT, and the ND1, ND4 and ND6 genes with TAT. All stop codons of the 13 PCGs were TAA/TAG or incomplete stop codons by T, except ND1 with CTG (TableS1), which are observed in the mitogenomes of beetles[59,62,75].The large ribosomal RNA (16S rRNA) of Scymnus (Pullus) cardi is 1276 bp in size, with an A + T content of 82%, and its small ribosomal RNA (12S rRNA) is 793 bp, with an A +…”

Museomics, molecular phylogeny and systematic revision of the Eurepini crickets (Orthoptera: Gryllidae: Eneopterinae), with description of two new genera

“…In this context, we took advantage of these advances and applied the genome skimming method to sequence relatively old Eurepini specimens including nearly all types of specimens. As genome skimming has been successfully used to recover considerable genetic information from a variety of historical specimens of various ages (e.g., Bakker et al, 2016; Besnard et al, 2014; de Abreu et al, 2020; Guschanski et al, 2013; Jin, Zwick, Slipinski, De Keyzer, & Pang, 2020; Jin, Zwick, Slipinski, Marris, et al, 2020; Salazar & Nattier, 2020; Zedane et al, 2016; Zeng et al, 2018), we managed to recover substantial amounts of genetic data, including complete or partially complete mitogenomes and nuclear rDNA for most of the specimens that were collected more than 50 years ago, demonstrating the high efficiency of genome skimming on such old materials. We were unable to recover genetic data for only four relatively old holotype specimens, which might be due to high degradation of DNA leading to the failure of DNA extraction to yield adequate DNA.…”