The genome sequence of the tapered dronefly, Eristalis pertinax (Scopoli, 1763)

We present a genome assembly from an individual male Eristalis pertinax (the tapered dronefly; Arthropoda; Insecta; Diptera; Syriphidae). The genome sequence is 487 megabases in span. The majority of the assembly (95.23%) is scaffolded into seven chromosomal pseudomolecules, with the X and Y sex chromosomes assembled. The complete mitochondrial genome was also assembled and is 17.2 kilobases in length.


Introduction
The tapered dronefly, Eristalis pertinax, is a fairly large hoverfly separated from others in the Eristalis genus by the presence of yellow tarsi on their front and middle legs. E. pertinax mimics the general shape and colouring of a honeybee, Apis mellifera, to gain protection against bird predation through Batesian mimicry. Their mimicry of their model species extends beyond simple colouration, as E. pertinax has been shown to spend similar times foraging and flying to that of Apis mellifera (Golding & Edmunds, 2000), as well as acoustic mimicry through 'defence buzzes' (Moore & Hassall, 2016).
E. pertinax is widespread in the British Isles, occurring in a range of habitats, perhaps favouring woodlands and wetlands. They can be found on the wing between March and November. Throughout the year, E. pertinax shows seasonal polyphenism through two distinct morphs (a larger, long-haired morph in the spring, and a smaller, short haired morph in the summer), presumably adaptive to the different seasonal temperatures (Mielczarek et al., 2016).
Male E. pertinax hoverflies are highly territorial, defending sunny patches of woodland rides or gardens where females are likely to rest or forage for food. These hoverflies feed on nectar from a wide variety of flowers, but hogweed (Heracleum sp.) and bramble (Rubus sp.) are thought to be their preferences (Herkenrath, 2014).
Their larvae are colloquially known as rat-tailed maggots and live in a wide array of organically rich pools. The larvae feed on decaying organic matter and therefore play a highly important ecological role in terms of decomposition (Hurtado et al., 2008). This is the first production of a high-quality E. pertinax genome; we believe that the sequence described here, generated as part of the Darwin Tree of Life project, will further aid understanding of the biology and ecology of this hoverfly.

Amendments from Version 1
The species was incorrectly named in the Abstract and Data availability section -this has been corrected. Figure 1 initially mistakenly included an image of Epistrophe eligans. This has been replaced with images of E. pertinax.
Other minor corrections in response to reviewer and commenter statements have been made.
Any further responses from the reviewers can be found at the end of the article

Genome sequence report
The genome was sequenced from a single male E. pertinax collected from Wytham Great Wood, Oxfordshire, UK (latitude 51.772, longitude -1.339) (see Figure 1 for an example photograph of E. pertinax). A total of 29-fold coverage in Pacific Biosciences single-molecule long reads and 73-fold coverage in 10X Genomics read clouds were generated. Primary assembly contigs were scaffolded with chromosome conformation Hi-C data. Manual assembly curation corrected 181 missing/misjoins, reducing the scaffold number by 32.45%, and increasing the scaffold N50 by 185.38%.
The final assembly has a total length of 482 Mb in 257 sequence scaffolds with a scaffold N50 of 77.5 Mb ( Table 1). The majority, 95.23%, of the assembly sequence was assigned to seven chromosomal-level scaffolds, representing five autosomes (numbered by sequence length), and the X and Y sex chromosomes (Figure 2- Figure 5; Table 2). The assembly has a BUSCO v5.1.2 (Simão et al., 2015) completeness of 96.3% using the diptera_odb10 reference set. While not fully phased, the assembly deposited is of one haplotype. Contigs corresponding to the second haplotype have also been deposited.

Methods
A male (idEriPert2) and a female (idEriPert1) E. pertinax sample were collected from Wytham Great Wood, Oxfordshire, UK (latitude 51.772, longitude -1.339) by Will Hawkes, University of Exeter on 1 August 2019 (idEriPert2) and 7 August 2019 (idEriPert1). The specimens were caught with a net, snap-frozen on dry ice and stored using a CoolRack.
DNA was extracted at the Tree of Life laboratory, Wellcome Sanger Institute (WSI). The idEriPert2 sample was weighed and dissected on dry ice with tissue set aside for Hi-C sequencing. Head/thorax tissue was cryogenically disrupted to a fine powder using a Covaris cryoPREP Automated Dry Pulveriser, receiving multiple impacts. Fragment size analysis of 0.01-0.5 ng of DNA was then performed using an Agilent FemtoPulse. High molecular weight (HMW) DNA was extracted using the Qiagen MagAttract HMW DNA extraction kit. Low molecular weight DNA was removed from a 200-ng aliquot of extracted DNA using 0.8X AMpure XP purification kit prior to 10X Chromium sequencing; a minimum of 50 ng DNA was submitted for 10X sequencing. HMW DNA was sheared into an average fragment size between 12-20 kb in a Megaruptor 3 system with speed setting 30. Sheared DNA was purified by solid-phase reversible immobilisation using AMPure PB beads with a 1.8X ratio of beads to sample to remove the shorter fragments and concentrate the DNA sample. The concentration of the sheared and purified DNA was assessed using a Nanodrop spectrophotometer and   and Pretext. The mitochondrial genome was assembled using MitoHiFi (Uliano-Silva et al., 2021), which performed annotation using MitoFinder (Allio et al., 2020). The genome was analysed and BUSCO scores generated within the BlobToolKit environment (Challis et al., 2020). Table 3 contains a list of all software tool versions used, where appropriate.

Open Peer Review
Are the datasets clearly presented in a useable and accessible format? Yes