Next generation sequencing-aided comprehensive geographic coverage sheds light on the status of rare and extinct populations of Aporia butterflies (Lepidoptera: Pieridae)

Abstract

the Black-veined White Aporia crataegi (Linnaeus, 1758), a common and widespread butterfly ranging from northwestern Africa to Europe and Asia, has been extinct in Britain since the 1920s and is on a steady decline in several other parts of its range. In order to investigate genetic diversity within A. crataegi and its correspondence with current subspecies-level taxonomy, we barcoded 173 specimens from across its range including, for the first time, extinct populations from Britain and Korea. Using next generation sequencing we also obtained a sequence for Aporia joubini, a peculiar taxon from China known only by its type specimen collected in the early twentieth century. Our phylogenetic analysis placed A. joubini sister to A. oberthuri, although further taxon sampling may reveal a different scheme. Within A. crataegi, we observed a shallow and weak mitogenomic structure with only a few distinct lineages in North Africa, Sicily, Iran, and Japan. Eurasian populations, including those extinct in Britain and Korea, clustered into a large set of closely allied lineages, consistent with a recent expansion during the Late Pleistocene glacial period. This study highlights the importance of museum collections and the unique opportunities they provide in documenting species diversity and helping conservation efforts. Human activities threaten considerable numbers of species and natural populations that, in turn, significantly affect ecosystem functioning 1,2. Each species contains immense amounts of genetic information within its geographical populations, and this intra-specific genetic diversity not only is a repository of past geological, climatic, and environmental information, but also influences population persistence and evolutionary potential 3. Thus, the resulting permanent loss of genetic information due to local extinctions not only affects evolutionary potential under changing environmental conditions, but also impedes a full understanding of the evolutionary history of species. Natural history collections have long been used by morphologists and taxonomists to probe the evolutionary process and describe biological diversity. These biological archives also offer great opportunities for genetic research in taxonomy, conservation, systematics, and population biology and they represent an invaluable resource for studying extinct taxa. Next Generation Sequencing (NGS) has revolutionized nearly every field of genetics, but few have profited from it as much as ancient DNA research. NGS has increased the amount of DNA sequence data available from extinct organisms by several orders of magnitude and is extensively used in phylogenetic studies using museum specimens [e.g. 4,5 ]. The Black-veined White, Aporia crataegi, is a well-known butterfly widespread in orchards and bushy places in the Palearctic region, from northwestern Africa to Japan, across Europe and Asia, although very localized and uncommon in some areas 6-8. Its larvae feed on Rosaceae such as Prunus, Pyrus, and especially Crataegus.

Is Aporia crataegi unsuitable host of Wolbachia symbionts?

“…The other mtDNA haplotype was found in infected and uninfected samples from Yakutia, and in uninfected samples from the Khabarovsk Krai. This haplotype belongs to the haplogroup previously described in Central and East Asia and Yakutia (Todisco et al, 2020), and it is probably typical for Asian populations of A. crataegi.…”

“…2A, B). One of these mtDNA haplotypes associated with Wolbachia haplotypes belongs to the most common and widespread «Eurasian» haplogroup (Todisco et al, 2020). This mtDNA haplotype was found in infected samples from Sverdlovsk and Kaliningrad Provinces and in uninfected samples from Novosibirsk, Kemerovo and Tomsk Provinces, Altai Krai, Republic of Buryatia and Altai Republic.…”

“…Phylogenetic reconstructions were performed in MEGA 6 by the maximum likelihood algorithm. The data on other populations of A. crataegi (Park et al, 2013;Kim et al, 2020;Todisco et al, 2020) with A. hippia as an outgroup taxon were used for mtDNA tree reconstruction.…”

“…Decreasing A. crataegi populations (Fokin, Korovin, 2001;Kim et al, 2015;Jugovic et al, 2017), have been observed in the territories of Northern, Central, Eastern and Southern Europe, and North Africa, primarily due to human activity (van Swaay et al, 2010;Todisco et al, 2020). Extinction of A. crataegi has been reported in England, Czech Republic, The Netherlands, and South Korea (Asher et al 2001;van Swaay et al, 2010;Park et al, 2013;Kim et al, 2020).…”

Long-distance dispersal of migrant butterflies to the Arctic Ocean islands, with a record of Nymphalis xanthomelas at the northern edge of Novaya Zemlya (76.95°N)

“…0°N, 69.5°E; 1976-1979] (Olschwang 1980), and several records throughout the Bolshezemelskaya Tundra [up to 68.17°N;-2004 (Tatarinov and Kulakova 2005). This migrant species shares a shallow phylogeographic structure throughout Northern Eurasia, including extinct populations in the United Kingdom and Korea (Todisco et al 2020).…”