Haplotype diversity and population genetic structure of Aethina tumida, an emerging global beekeeping pest in India

The small hive beetle (SHB) ( Aethina tumida Murray) is an invasive pest of apiculture globally that has invaded many regions over the past three decades. In India, it was first reported in 2022 from honey bee colonies in North 24 Parganas, West Bengal. Investigating the population structure and genetic diversity of A. tumida is essential for tracing invasion pathways, identifying its origin and facilitating the formulation of effective integrated pest management approaches. In this study, we collected SHB populations from different geographical regions of India to assess their genetic diversity. A total of 460 specimens were collected from 44 distinct localities across eight SHB-infested states. Mitochondrial cytochrome c oxidase subunit I (COI) gene was employed to unveil the genetic diversity, phylogenetic relationships and probable invasion source of A. tumida in India. Global analysis of 393 COI sequences identified 92 distinct haplotypes, with haplotype H61 emerging as the most widespread and occurring across three continents. Haplotype diversity was highest in Africa and lowest in South America, whereas nucleotide diversity was highest in Asia and lowest in South America. Within India, three haplotypes were detected with H1 being predominant. East India exhibited the highest haplotype (Hd:0.127) and nucleotide diversity (Pi:0.00016). Molecular phylogenetic and haplotype network analyses revealed a shared haplotype between Bangladesh and Indian populations, suggesting a possible genetic connection and highlighting Bangladesh as a plausible source of A. tumida invasion into India. The present study provides the first comprehensive evaluation of A. tumida genetic variation in India within a global context.