Genome assembly and completeness assessment
Long reads derived from Sequel System were assembled using the HGAP4 assembler (https://www.pacb.com/support/software-downloads/). To construct consensus sequences from draft contigs from HGAP4, Racon (Vaser, Sovic, Nagarajan, & Sikic, 2016) with minimap (Li, 2016) was employed. Racon treatment was repeated until the output FASTA file showed no difference from that of the previous run. In this case, four repeats were sufficient to obtain final results. Then, in order to polish the assembly, Pilon (Walker et al., 2014) was utilized with Illumina short reads. The final assembly was submitted to BUSCO v3 software (Waterhouse et al., 2018) to assess the completeness of the assembly. For comparison, the latest genome assembly of 4 lepidopteran species, including B. mori , Papilio xuthus , Danaus plexippus and Plutella xylostella , was also sumitted to BUSCO.