Molecular systematics of the subfamily Limenitidinae (Lepidoptera: Nymphalidae)

Measuring and Modelling Structural Colours of Euphaedra neophron (Lepidoptera: Nymphalidae) Finely Tuned by Wing Scale Lower Lamina in Various Subspecies

The nymphalid butterfly Euphaedra neophron (Hopffer, 1855) is the only structurally coloured species representing the genus along the Indian Ocean coast in East Africa and Southern Africa, with a distribution from southern Somalia to the Kwa-Zulu-Natal region of South Africa. The range of E. neophron is subdivided to several, geographically distinct populations, currently recognised as subspecies by taxonomists on the basis of violet, blue, and green-coloured morphs. We investigated the optical mechanism of all these morphs by various materials science techniques. We found that the structural colour is generated by the lower lamina of the cover scales and the different colours are tuned according to their thickness, which was also proved by modelling. The colour tuning of the different subspecies does not reflect any clinal pattern, be it geographical or altitudinal.

Complete mitochondrial genome data and phylogenetic analysis of the Great Marquis, Bassarona dunya (Doubleday, 1848) (Lepidoptera: Nymphalidae: Limenitidinae) from Malaysia

The Great Marquis or Bassarona dunya is a butterfly species commonly found in the tropical regions of Asia, America, and Africa. This butterfly is a member of the subfamily Limenitidinae and the classification within this subfamily has been unstable. Here, we report the first complete mitochondrial genome (mitogenome) of B. dunya sampled from Malaysia. The mitogenome is 15,242 bp long, comprising a set of 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs), and an A + T rich region. All PCGs were initiated by the typical ATN codon, except for COX1 which started with a CGA start codon. Nine PCGs were terminated with a TAA or TAG stop codon, while COX1, COX2, NAD4, and NAD5 ended with an incomplete T. The 12S and 16S rRNAs were 716 bp and 1269 bp in length, respectively. Phylogenetic analysis supported the placement of B. dunya within Limenitidinae with a high support value.

The Complete Mitochondrial Genomes of Four Species in the Subfamily Limenitidinae (Lepidoptera, Nymphalidae) and a Phylogenetic Analysis

Simple Summary

As it is currently delineated, the subfamily Limenitidinae (Lepidoptera: Nymphalidae) is comprised of 50 genera with approximately 1100 species. The classification of this subfamily has always been unstable. There are tribes and genera whose status is doubtful. Their phylogenetic relationships are far from being clarified and the monophyly of some of them is under question. To provide further insight into the relationships among included tribes, four newly-completed mitochondrial genomes of Limenitidinae (Neptis thisbe, Athyma zeroca, and Aldania raddei) have been sequenced and analyzed. Results indicate that the gene orientation and arrangement are similar to typical mitogenomes in Lepidoptera. The inferred phylogenetic analysis shows that tribe levels are well-supported monophyletic groups. Taken together, this work will provide a well-resolved framework for future study of this subfamily.

Abstract

The complete mitogenomes of four species, Neptis thisbe, Neptis obscurior, Athyma zeroca, and Aldania raddei, were sequenced with sizes ranging from 15,172 bp (N. obscurior) to 16,348 bp (Al. raddei). All four mitogenomes display similar nucleotide content and codon usage of protein-coding genes (PCGs). Typical cloverleaf secondary structures are identified in 21 tRNA genes, while trnS1 (AGN) lacks the dihydrouridine (DHC) arm. The gene orientation and arrangement of the four mitogenomes are similar to that of other typical mitogenomes of Lepidoptera. The Ka/Ks ratio of 13 PCGs among 58 Limenitidinae species reveals that cox1 had the slowest evolutionary rate, while atp8 and nad6 exhibited a higher evolutionary rate. The phylogenetic analysis reveals that tribe-levels are well-supported monophyletic groups. Additionally, Maximum Likelihood analysis recovered the relationship (Parthenini + ((Chalingini + (Cymothoini + Neptini)) + (Adoliadini + Limenitidini))). However, a Bayesian analysis based on the same dataset recovered the relationship (Parthenini + (Adoliadini + ((Cymothoini + Neptini) + (Chalingini + Limenitidini)))). These results will offer valuable data for the future study of the phylogenetic relationships for Limenitidinae.

A glide over the Indo-Australian geological maze: repeated transgressions of Lydekker’s and Wallace’s Lines in archdukes, barons and dukes (Nymphalidae: Limenitidinae: Adoliadini)

Archdukes, barons, counts, dukes and marquises are forest-dwelling butterflies found in mainland Asia and most islands of the Indo-Australian archipelago west of Wallace’s Line, with only a few species occurring as far east as the Bismarck Archipelago. This pattern is unusual among butterfly groups of the region, which often present more widespread geographical ranges bearing little signature of Lydekker’s and Wallace’s Lines. Using a molecular multimarker matrix, we infer the first dated phylogeny for this clade and estimate its biogeographical history. We recover the Oriental genus Euthalia as polyphyletic, although other genera are monophyletic. The clade originated in continental Indomalaya in the late Oligocene ~24 Mya, when the Indo-Australian archipelago was at one of the most dynamic stages of its orogeny. Multiple independent colonization events towards the Lesser Sunda Islands, Moluccas, Australia and New Guinea suggest the relative permeability of Lydekker’s and Wallace’s Lines to these butterflies. Colonization of Melanesia took place twice, probably before the recent formation of Sulawesi. The study of Indo-Australian Adoliadini provides additional evidence that biogeographical barriers long thought to prevent exchange between the Asian and Australian biotas are, in fact, permeable especially to vagile insect lineages in the region.

Unravelling relationships among the shared stripes of sailors: Mitogenomic phylogeny of Limenitidini butterflies (Lepidoptera, Nymphalidae, Limenitidinae), focusing on the genera Athyma and Limenitis

The phylogenetic relationships of the nymphalid butterfly tribe Limenitidini are best known for the genera Limenitis and Adelpha, model taxa for evolutionary processes such as Batesian mimicry and rapid adaptive radiations. Whereas these American limenitidines have received the most attention, phylogenetic relationships of their Asian relatives are still controversial and largely unexplored. Even one of the largest genera in Asia, Athyma, is polyphyletic. To clarify the phylogenetic relationships of these Asian Limenitidini, a total of 53 representatives were sampled; 37 have their mitogenomes sequenced for the first time. Our phylogenetic results confirm that mitogenomic data provides well-resolved relationships at most major levels of the phylogeny, even using different partition schemes or different inference methods. Interestingly, our results show that some Athyma taxa are embedded within the genus Limenitis, whereas the genus Tacola, previously considered to be a synonym of Athyma, needs to be recognized as a valid clade. Additionally, the other Limenitidini genera in Asia (namely Tarattia, Litinga, Sumalia, Pandita and Patsuia) are now grouped either within Athyma or Limenitis, so these genera need to be sunk. Importantly, we also show that the mainly Old World Limenitis and entirely New World Adelpha are sister groups, confirming the relevance of Asian lineages to global studies of Limenitis evolution.

A simple method for data partitioning based on relative evolutionary rates

BACKGROUND

Multiple studies have demonstrated that partitioning of molecular datasets is important in model-based phylogenetic analyses. Commonly, partitioning is done a priori based on some known properties of sequence evolution, e.g. differences in rate of evolution among codon positions of a protein-coding gene. Here we propose a new method for data partitioning based on relative evolutionary rates of the sites in the alignment of the dataset being analysed. The rates are inferred using the previously published Tree Independent Generation of Evolutionary Rates (TIGER), and the partitioning is conducted using our novel python script RatePartitions. We conducted simulations to assess the performance of our new method, and we applied it to eight published multi-locus phylogenetic datasets, representing different taxonomic ranks within the insect order Lepidoptera (butterflies and moths) and one phylogenomic dataset, which included ultra-conserved elements as well as introns.

METHODS

We used TIGER-rates to generate relative evolutionary rates for all sites in the alignments. Then, using RatePartitions, we partitioned the data into partitions based on their relative evolutionary rate. RatePartitions applies a simple formula that ensures a distribution of sites into partitions following the distribution of rates of the characters from the full dataset. This ensures that the invariable sites are placed in a partition with slowly evolving sites, avoiding the pitfalls of previously used methods, such as k-means. Different partitioning strategies were evaluated using BIC scores as calculated by PartitionFinder.

RESULTS

Simulations did not highlight any misbehaviour of our partitioning approach, even under difficult parameter conditions or missing data. In all eight phylogenetic datasets, partitioning using TIGER-rates and RatePartitions was significantly better as measured by the BIC scores than other partitioning strategies, such as the commonly used partitioning by gene and codon position. We compared the resulting topologies and node support for these eight datasets as well as for the phylogenomic dataset.

DISCUSSION

We developed a new method of partitioning phylogenetic datasets without using any prior knowledge (e.g. DNA sequence evolution). This method is entirely based on the properties of the data being analysed and can be applied to DNA sequences (protein-coding, introns, ultra-conserved elements), protein sequences, as well as morphological characters. A likely explanation for why our method performs better than other tested partitioning strategies is that it accounts for the heterogeneity in the data to a much greater extent than when data are simply subdivided based on prior knowledge.