AUTHOR=Sun Huiquan , Jia Feiran , Zhao Wenxia , Zhou Zhongfu , Li Chengjin , Wang Jianjun , Yao Yanxia 

TITLE=Population Genetics Reveals That the Western Tianshan Mountains Populations of Agrilus mali (Coleoptera: Buprestidae) May Have Not been Recently Introduced

JOURNAL=Frontiers in Genetics

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2022.857866

DOI=10.3389/fgene.2022.857866

ISSN=1664-8021

ABSTRACT=<p><italic>Agrilus mali</italic> Matsumura is a wood-boring beetle that aggressively attacks species of the genus <italic>Malus,</italic> that has recently caused serious damage to the wild apple tree <italic>M</italic>. <italic>sieversii</italic> (Lebed.) in the western Tianshan Mountains in Xinjiang. It was first detected there in the early 1990s and spread rapidly, being thus considered a regional invasive pest. To explore the possible outbreak mechanism of the local population and characterize the genetic differentiation of <italic>A. mali</italic> across different regions of China, we used three mitochondrial genes (<italic>COI</italic>, <italic>COII</italic>, and <italic>CytB</italic>) to investigate the genetic diversity and genetic structure of 17 <italic>A. mali</italic> populations containing 205 individuals collected from five Chinese provinces. Among them, nine populations were from the western Tianshan Mountains. Ultimately, of the 136 pairwise <italic>F</italic><sub><italic>st</italic></sub> comparisons, 99 showed high genetic differentiation among overall populations, and Tianshan populations exhibited significant differentiation with most of the non-Tianshan populations. Furthermore, <italic>A. mali</italic> populations represented relatively abundant haplotypes (54 haplotypes). Nine populations from the Tianshan Mountains showed 32 haplotypes (26 of which were unique), displaying relatively high genetic diversity. Additionally, the Mantel test revealed population genetic differentiation among either overall populations or the Tianshan Mountains populations, likely caused by geographical isolation. Phylogenic relationships showed that all populations clustered into three clades, and Tianshan Mountains populations, including CY, occupied one of the three clades. These results suggest that <italic>A. mali</italic> in the western Tianshan region has possibly been present in the area for a long period, and may not have been introduced recently. Highly frequent gene flows within Tianshan populations are possibly caused by human activities and may enhance the adaptability of <italic>A. mali</italic> along the western Tianshan Mountains, leading to periodic outbreaks. These findings enhance our understanding of jewel beetle population genetics and provide valuable information for pest management.</p>