Chromosome level draft genomes of the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), an alien invasive pest in China

Abstract

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) is a severely destructive pest native to the Americas, but has now become an alien invasive pest in China, and causes significant economic loss. Therefore, in order to make effective management strategies, it is highly essential to understand genomic architecture and its genetic background. In this study, we assembled two chromosome scale genomes of the fall armyworm, representing one male and one female individual procured from Yunnan province of China. The genome sizes were identified as 542.42 Mb with N50 of 14.16 Mb, and 530.77 Mb with N50 of 14.89 Mb for the male and female FAW, respectively. We predicted about 22,201 genes in the male genome. We found the expansion of cytochrome P450 and glutathione s-transferase gene families, which are functionally related to the intensified detoxification and pesticides tolerance. Further population analyses of corn strain (C strain) and rice strain (R strain) revealed that the Chinese fall armyworm was most likely invaded from Africa. These strain information, genome features and possible invasion source described in this study will be extremely important for making effective strategies to manage the fall armyworms.

Adaptation by copy number variation increases insecticide resistance in fall armyworms

“…Our new assembly has a higher proportion of complete BUSCO genes than the assembly by Liu et al ( Table 1). In addition, our new assembly has a lower proportion of duplicated BUSCO genes (28/1658 = 1.69%) than the assemblies from Liu et al 25 (134/1658 = 8.08% for male assembly, 97/1658 = 5.86% for female assembly). From this BUSCO analysis, we concluded that our assembly has higher accuracy than the assemblies from Liu et al 25 .…”

“…In addition, our assembly has better contiguity because of a much smaller number of contigs and a much smaller L90 value than the assembly by Liu et al 25 (Table 1).…”

“…Recently, Liu et al published another new reference genome assemblies from invasive fall armyworms 25 . The assemblies are substantially larger than the expected genome size (530.77Mb -542.42Mb), raising the possibility of misassemblies.…”

“…Summary statistics of reference genome assembly and the result of BUSCO analysis from the assembles used in this study and in Liu et al25 .…”

Genomic features of the fall armyworm (Spodoptera frugiperda) (J.E. Smith) yield insights into its defense system and flight capability

“…Smith) (Lepidoptera: Noctuidae), an invasive pest native to tropical and subtropical America, is an economically destructive pest (Midega et al ). FAW has been dispersed from its native region invading Africa in 2016 (Goergen et al ) and many Asian countries in 2018 (Liu et al ). FAW attacks maize and other graminaceous crops, and its host range includes 186 plant species in 42 families (Casmuz et al ).…”