Abstract
Simple SummaryTenthredinidae is the most speciose family of the paraphyletic ancestral grade Symphyta, including mainly phytophagous lineages. The subfamilial classification of this family has long been problematic with respect to their monophyly and/or phylogenetic placements. This article reports four complete sawfly mitogenomes of Cladiucha punctata, C. magnoliae, Megabeleses magnoliae, and M. liriodendrovorax for the first time. To investigate the mitogenome characteristics of Tenthredinidae, we also compare them with the previously reported tenthredinid mitogenomes. To explore the phylogenetic placements of these four species within this ecologically and economically important sawfly family, we perform the mitophylogenomics reconstruction and divergence time estimation analyses using a mitogenome dataset of 45 species of the superfamily Tenthredinoidea. Although these newly reported four species have currently classified in the subfamily of Allantinae, the obtained tree topology reveals the sister-group placement of Cladiucha and Megabeleses outside of Blennocampinae, Heterarthrinae, Tenthredininae, and the rest of Allantinae as a distinct lineage. In conjunction with the occurrence of morphological and molecular synapomorphic characters, apparent matches the reported divergence times of their host plants from Magnoliaceae—supporting the proposal of Megabelesesinae as a subfamily. This study represents a broad framework and valuable information for future research on this small subfamily.Tenthredinidae represents one of the external feeders of the most diverse superfamily, Tenthredinoidea, with diverse host plant utilization. In this study, four complete mitochondrial genomes (mitogenomes), those of Cladiucha punctata, Cladiucha magnoliae, Megabeleses magnoliae, and Megabeleses liriodendrovorax, are newly sequenced and comparatively analyzed with previously reported tenthredinid mitogenomes. The close investigation of mitogenomes and the phylogeny of Tenthredinidae leads us to the following conclusions: The subfamilial relationships and phylogenetic placements within Tenthredinidae are mostly found to be similar to the previously suggested phylogenies. However, the present phylogeny supports the monophyly of Megabelesesinae as a subfamily, with the sister-group placement of Cladiucha and Megabeleses outside of Allantinae. The occurrence of the same type of tRNA rearrangements (MQI and ANS1ERF) in the mitogenomes of Megabelesesinae species and the presence of apomorphic morphological characters also provide robust evidence for this new subfamily. The divergence and diversification times of the subfamilies appear to be directly related to colonization of the flowering plants following the Early Cretaceous. The origin time and diversification patterns of Megabelesesinae were also well matched with the divergence times of their host plants from Magnoliaceae.
Highlights
The exclusively herbivorous larvae of Tenthredinidae are mostly simple external feeders that feed on a wide variety of leaves, but a few are leaf miners, gall causers, or stem borers [1]
Each mitogenome consisted of a typical set of 37 genes: Thirteen protein-coding genes (PCGs), twenty-two tRNAs, two rRNAs, and an A + T
The observed length variation among these mitogenomes was primarily due to variation in the A + termination codons (T-)rich region (Table S4)
Summary
The exclusively herbivorous larvae of Tenthredinidae are mostly simple external feeders that feed on a wide variety of leaves, but a few are leaf miners, gall causers, or stem borers [1]. The family is almost globally distributed and is more diverse in the Northern. The observed distribution pattern is affected by adults who are slow fliers; this trait limits the distribution of the larvae of this diverse family on host plants. In addition to contributing to the overall distribution pattern, the host plant preferences of tenthredinid larvae have led to an increase in speciation events by host switching, in sublineages that feed on only some angiosperms [4]. This family is the largest and a considerably complex family of Symphyta, comprising
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
