New insights into the genetic structure of the outbreak-prone migratory locust

Abstract

The genetic structure of species is shaped by several natural and non-natural factors. Although geographical isolation and natural barriers are important causes of genetic structure formation of species, the effects of dispersal potential and population outbreaks remain controversial. Here, we explored this issue in a migratory locust, Ceracris kiangsu, which is an important pest that feeds on bamboo in East and Southeastern Asia. Based on 187 newly sequenced and 286 previously sequenced mitochondrial COI fragments, and 8 nuclear microsatellite loci, we studied the genetic diversity and population genetic structure of C. kiangsu. Both molecular markers revealed high genetic diversity of the geographic populations that possibly resulted from the high flight capacity of the locust. The degree of genetic differentiation among populations was also high, and Mantel test showed that it was significantly correlated with geographical distance. Principal coordinate analysis and STRUCTURE results revealed two genetically different groups, a South China (S-China) Group and a Southeast Asia (SE-Asia) Group. Climate variables well explained the population genetic structure. The demographic history showed that the S-China Group experienced population expansion in the Holocene, whereas the SE-Asia Group was consistently stable. A southeast population (Guangxi) might have been a refuge prior to Holocene expansion. Our study demonstrates a distinct population structure maintained in this migratory insect and reveals the potential effect of past climatic change, geographical isolation, and ecological factors on the evolution of their genetic structure.

New insights into the genetic structure of the outbreak-prone bamboo grasshoppers

“…We express our sincere gratitude to Yuyang Cheng, Shuanghui Li, and Wei Zhang for sample collection, to Xianliang Huang for his technical guidance and suggestions, and to Mallory Eckstut for editing the English text of this manuscript. The preprint entitled "New insights into the genetic structure of the outbreak-prone migratory locust" was published on Authorea Team (Song et al, 2022(Song et al, ). 10.3389/fevo.2023 Frontiers in Ecology and Evolution 12 frontiersin.org…”