The genome sequence of the yellow-legged clearwing, Synanthedon vespiformis (Linnaeus, 1761)

We present a genome assembly from an individual male Synanthedon vespiformis (the yellow-legged clearwing; Arthropoda; Insecta; Lepidoptera; Sesiidae). The genome sequence is 287 megabases in span. Of the assembly, 100% is scaffolded into 31 chromosomal pseudomolecules with the Z sex chromosome assembled. The complete mitochondrial genome was also assembled and is 17.3 kilobases in length.


Background
The yellow-legged clearwing, Synanthedon vespiformis (Linnaeus, 1761), is a day flying, clearwing moth belonging to the family Sesiidae. Adults exhibit wasp mimicry, as with many others in the Sesiidae family. It is widespread in the Palearctic, including England and eastern Wales, but its range does not extend to the north of the British Isles or Ireland S. vespiformis is characterised as a woodland species, principally inhabiting the host-plant genus Quercus in northern latitudes, as well as other genera such as Populus, Aesculus and Salix ("Synanthedon Vespiformis (Linnaeus, 1761)" n.d.). The larvae are internal feeders, as with other Sesiidae, and are considered forestry pests in many of its southern ranges, including of the European chestnut, Castanea sativa, native to Turkey (Ülgentürk & Dokuyucu, 2019). S. vespiformis DNA has not previously been barcoded in the UK and the assembly could be used for further research into haplotype diversity from European DNA barcodes (BOLD:AAD7411). Loci could be evaluated for known traits, such as wasp mimicry.

Genome sequence report
The genome was sequenced from a single male S. vespiformis collected from Wytham Woods, Berkshire, UK ( Figure 1). A total of 94-fold coverage in Pacific Biosciences single-molecule HiFi long reads and 129-fold coverage in 10X Genomics read clouds were generated. Primary assembly contigs were scaffolded with chromosome conformation Hi-C data. Manual assembly curation corrected 6 missing/misjoins, reducing the assembly size by 0.01% and the scaffold number by 13.89%, and increasing the scaffold N50 by 1.03%.
The final assembly has a total length of 287 Mb in 31 sequence scaffolds with a scaffold N50 of 10.4 Mb ( Table 1). Of the assembly sequence, 100% was assigned to 31 chromosomal-level scaffolds, representing 30 autosomes (numbered by sequence length) and the Z sex chromosome (Figure 2- Figure 5; Table 2). Chromosome 23 contains a possible heterozygous inversion (1.45-4.5Mb). We cannot be sure of the orientation of the chromosome between these coordinates.
The genome sequence is released openly for reuse. The S. vespiformis genome sequencing initiative is part of the Darwin Tree of Life (DToL) project. All raw sequence data and the assembly have been deposited in INSDC databases. The genome will be annotated and presented through the Ensembl pipeline at the European Bioinformatics Institute. Raw data and assembly accession identifiers are reported in Table 1.

CNRS -Université de Tours,, Tours, France
The genome report of the Lepidoptera synanthedon vespiformis begins with an introduction describing the natural history of the species, followed by technical aspects of genome sequencing performed to obtain high-quality genome chromosome scale assembly as in other data notes from the Darwinian tree of life project. The introduction is well written and will be of interest for a broad audience, whereas the detailed protocol and figures will be understood by specialists in genomics. The genome obtained using a combination of the best available approaches is of high quality and at chromosomal scale. The values assessing quality are all very good. This genome will provide a strong reference for future studies provided that some effort is put on the study of the genetic of mimicry that makes this and related lepidopteran species look like wasps which is quite fascinating. It will also be of interest to check for horizontal transfers of genes from their parasites, that have been shown to impact many lepidopteran genomes 1,2 .
By searching on the internet to find information potentially missing I did not find much to add: the scientific literature is scarce on this species. The only criticism I can provide is on the rather obscure sentence on whether the species distribution may have decreased in the UK since 1970 since as stated the sampling method now using pheromones is completely different from that used for old records. The reference cited for this sentence is not "open access" which prevent a better understanding of this point. Concerning the pest status one can also mention that it appears to be a pest also for stone fruits in Israël 3 , which is probably one of the reasons why pheromone lures have been developed. On the other hand, the adult has probably a beneficial role as pollinator, as most Lepidoptera, as suggested by many pictures showing them foraging on flowers, but I did not find any reference on this potential role. There might be also sexual dimorphism interesting to mention but again I did not find a reference on that topic.