Rota, J. | bioRxiv Science

bioRxiv2022

Evolutionary history of Euteliidae (Lepidoptera, Noctuoidea)

The Euteliidae stand apart in the Noctuoidea as the second smallest family, but most highly specialized in terms of larval hostplant relationships, favouring plant families with high levels of resin or latex, including the family dominant in Oriental lowland forests, the Dipterocarpaceae. Given the proportionally large foliage biomass represented by dipterocarps, exploitation of this abundant resource by lepidopteran defoliators is surprisingly low, and the Euteliidae may have achieved this through pre-adaption to dipterocarp chemical defences. Therefore, to assess this, we performed a molecular phylogenetic analysis on the family Euteliidae to clarify deep divergences and elucidate evolutionary relationships at the level of the subfamily, tribe, and genus. Our dataset consists of 6.3 kbp of one mitochondrial and seven nuclear DNA loci and was analyzed using model-based phylogenetic methods, i.e., maximum likelihood and Bayesian inference. We attempted to diagnose apomorphic morphological character states for Euteliidae and each monophyletic group within the family. Additionally, the evolution of hostplant use was reconstructed and a molecular-dating approach was conducted to assess the ages of major lineages within Euteliidae. We present an updated phylogenetic hypothesis for Euteliidae consisting of two strongly supported subfamilies: Euteliinae and Stictopterinae. Within Stictopterinae there are two tribes: Stictopterini and Odontodini. Several genera (e.g., Targalla, Paectes, Marathyssa, Eutelia) were found to be polyphyletic and require taxonomic revision. Two new genera (Niklastelia and Pellinentelia) are described and several taxonomic changes (e.g., new combinations and new synonymies) are made. The Neotropical genus Thyriodes, currently included in Euteliidae, is found to be associated with Erebinae (Erebidae). The divergence time estimate for the split between the Euteliidae and Noctuidae is at 53 my, and the Euteliidae split into the subfamilies Euteliinae and Stictopterinae at 42 my. In Stictopterinae, the tribes Stictopterini and Odontodini split at 31 my and the Euteliinae began a much more complex diversification at 34 my. Ancestral hostplant reconstruction identified Malpighiales (e.g., Clusiaceae) as the ancestral larval hostplant order for the family Euteliidae. The ancestors of Stictopterinae also appear to have been Malpighiales feeders, but then split into exclusive specialisms on Malvales (Odontodini) and Malpighiales (Stictopterini) hostplants. Larvae of Stictopterini appear to be restricted to Clusiaceae, apart from a few records from Dipterocarpaceae. In Euteliinae, Anacardiaceae are predominant as larval hosts. Thus, all hosts in the family are lactiferous, possibly providing some degree of pre-adaptation for exploiting Dipterocarpaceae.

evolutionary biology↗

bioRxiv2021

The unresolved phylogenomic tree of butterflies and moths (Lepidoptera): assessing the potential causes and consequences

The field of molecular phylogenetics is being revolutionised with next-generation sequencing technologies making it possible to sequence large numbers of genomes for non-model organisms ushering us into the era of phylogenomics. The current challenge is no longer how to get enough data, but rather how to analyse the data and how to assess the support for the inferred phylogeny. We focus on one of the largest animal groups on the planet - butterflies and moths (order Lepidoptera). We clearly demonstrate that there are unresolved issues in the inferred phylogenetic relationships of the major lineages, despite several recent phylogenomic studies of the group. We assess the potential causes and consequences of the conflicting phylogenetic hypotheses. With a dataset consisting of 331 protein-coding genes and the alignment length over 290 000 base pairs, including 200 taxa representing 81% of lepidopteran superfamilies, we compare phylogenetic hypotheses inferred from amino acid and nucleotide alignments. The resulting two phylogenies are discordant, especially with respect to the placement of the superfamily Gelechioidea, which is likely due to compositional bias of both the nucleotide and amino acid sequences. With a series of analyses, we dissect our dataset and demonstrate that there is sufficient phylogenetic signal to resolve much of the lepidopteran tree of life. Overall, the results from the nucleotide alignment are more robust to the various perturbations of the data that we carried out. However, the lack of support for much of the backbone within Ditrysia makes the current butterfly and moth tree of life still unresolved. We conclude that taxon sampling remains an issue even in phylogenomic analyses, and recommend that poorly sampled highly diverse groups, such as Gelechioidea in Lepidoptera, should receive extra attention in the future.

evolutionary biology↗