Microsatellite and Morphological Analyses Reveal Unexpected Diversity in Lymantria dispar in China

Abstract

The gyspy moth Lymantria dispar Linnaeus, a widely distributed leaf-eating pest, is considered geographically isolated in the world, with two Asian gypsy moth subspecies, Lymantria dispar asiatica and Lymantria dispar japonica. In China, only one subspecies, L. d. asiatica, has been observed. In this study, we characterized gypsy moth diversity and divergence using 427 samples covering a wide range of the species distribution, with a focus on sampling along a latitudinal gradient in China. We combine the quantitative analysis of male genitalia and the genetic diversity analysis of nine microsatellite loci of nuclear genes nuclear genes to study the structure of gypsy moth individuals in 23 locations in the world and the male genitalia of gypsy moths in some areas. In mixed ancestry model-based clustering analyses based on nuclear simple sequence repeats, gypsy moths were divided into three well-known subspecies, a unique North American cluster, and a southern Chinese cluster with differentiation between the Asian gypsy moth and European gypsy moth. We also found individuals identified as European gypsy moths in two distant regions in China. The results of a quantitative analysis of male genitalia characteristics were consistent with an analysis of genetic structure and revealed the differentiation of gypsy moths in southern China and of hybrids suspected to be associated with L. d. japonica in the Russian Far East. Admixture in gypsy moths can be explained by many factors such as human transport. In China, we detected European gypsy moths, and found unexpectedly high genetic diversity within populations across a wide range of latitudes.

Range‐wide population genomics of the spongy moth, Lymantria dispar (Erebidae): Implications for biosurveillance, subspecies classification and phylogeography of a destructive moth

“…In continental East Asia, our analyses recovered five genetically different groups whereas earlier work led to the identification of only two to four such clusters (Chen et al, 2013 , 2016 ; Kang et al, 2017 ; Keena et al, 2008 ; Wu et al, 2015 ; Zhao et al, 2019 ; Zuo et al, 2019 ). These five groups displayed genetic distances that mirrored their geographic locations in continental east Asia, but, interestingly, the southernmost Chinese population (CN08 in the Anhui province) revealed genetic proximity with moths from central Asia and Siberia located more than 3000 km away.…”

Analyses of adult transcriptomes from four different populations of the spongy moth, Lymantria dispar L., from China and the USA

“…The L. dispar genome, at approximately 1.0 Gb 31 , 32 , dwarfs the majority of sequenced Lepidoptera genomes that, on average, range from 250 to 500 Mb in size 25 . Genetic analysis has shown that ASM populations are more genetically diverse than ESM populations 33 . These features pose challenges to the identification of genes whose expression may account for the distinctive flightworthiness of ASM females.…”

Effects of Rearing Density on Developmental Traits of Two Different Biotypes of the Gypsy Moth, Lymantria Dispar L., from China and the USA

“…Once received, European gypsy moths were reared in the quarantine facility at Beijing Forestry University. These three populations were used in previous studies documenting their genetic diversity [ 19 , 20 , 21 ].…”