Morphology and Molecules Reveal Unexpected Cryptic Diversity in the Enigmatic Genus Sinobirma Bryk, 1944 (Lepidoptera: Saturniidae)

Rodolphe Rougerie,Wolfgang A Nässig,Stefan Naumann,Dirk Steinke

doi:10.1371/journal.pone.0043920

Rodolphe Rougerie, Wolfgang A Nässig + Show 2 more

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https://doi.org/10.1371/journal.pone.0043920

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Abstract

The wild silkmoth genus Sinobirma Bryk, 1944 is a poorly known monotypic taxon from the eastern end of the Himalaya Range. It was convincingly proposed to be closely related to some members of an exclusively Afro-tropical group of Saturniidae, but its biogeographical and evolutionary history remains enigmatic. After examining recently collected material from Tibet, northern India, and northeastern Myanmar, we realized that this unique species, S. malaisei Bryk, 1944 only known so far from a few specimens and from a very restricted area near the border between north-eastern Myanmar and the Yunnan province of China, may in fact belong to a group of closely related cryptic species. In this work, we combined morphological comparative study, DNA barcoding, and the sequences of a nuclear marker (D2 expansion segment of the 28S rRNA gene) to unequivocally delimit three distinct species in the genus Sinobirma, of which two are described as new to science: S. myanmarensis sp. n. and S. bouyeri sp. n. An informative DNA barcode sequence was obtained from the female holotype of S. malaisei—collected in 1934—ensuring the proper assignation of this name to the newly collected and studied specimens. Our findings represent another example of the potential of coupling traditional taxonomy and DNA barcoding for revealing and solving difficult cases of cryptic diversity. This approach is now being generalized to the world fauna of Saturniidae, with the participation of most of the taxonomists studying these moths.

Highlights

The genus Sinobirma was described by Bryk [1] as a subgenus of the Indo-Australian genus Opodiphthera Wallengren, 1858
The present study proposes the description of two new species closely related to Sinobirma malaisei, based on morphology, DNA barcodes and the congruent evidence from a nuclear marker (28S rRNA)
It is remarkable that the material recently made available for the genus Sinobirma, very rarely collected moths, proved to encompass three distinct species in the Indo-Himalayan region

Summary

Introduction

The genus Sinobirma was described by Bryk [1] as a subgenus of the Indo-Australian genus Opodiphthera Wallengren, 1858. Forgotten for half a century, this moth was redescribed from Malaise’s original material by Nassig & Oberprieler [2] and raised to genus level based on morphological differences in wing pattern, antennae and male genitalia structures. Most notably, these authors revealed the phylogenetic uniqueness of this genus and hypothesized that it is the first nonAfrotropical representative of the tribe Urotini Packard, 1902 (mentioned by Nassig & Oberprieler as Pseudapheliini Packard, 1914, but see Oberprieler [3] for the correct name, and an overview of the nomenclature in Naumann [4]) within the subfamily Saturniinae. The ongoing DNA barcoding campaign for saturniid moths (see Lepidoptera Barcode of Life at www.lepbarcoding.org; e.g. [8,9]) offered the opportunity to investigate genetic variation among the material available and proved decisive in sorting specimens of Sinobirma malaisei from various origins, as well as in understanding the significance of the subtle morphological variations preliminarily observed

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