The journey into the ecology and distribution of the genus Amblyomma in southern Africa

Abstract

The genus Amblyomma represents a fascinating and ecologically diverse group of hard ticks, widely distributed across southern Africa. Despite their importance as vectors of numerous pathogens, many species remain poorly studied, with limited ecological, seasonal, and distributional records. In this review we discuss observed patterns of sympatry and parapatry, noting that reproductive interference mediated by species-specific attraction-aggregation-attachment (AAA) pheromones may play a key role in shaping species boundaries. Molecular analyses using mitochondrial markers (12S rRNA, 16S rRNA, coi, and cytb) reveal high intraspecific variation within A. variegatum. The limited differentiation between A. pomposum and A. variegatum suggests recent divergence, motivating further genome-wide investigations. Additionally, we document the introduction of A. hebraeum and A. lepidum into established ranges of other species, emphasising the need for ongoing surveillance to assess the ecological consequences of such events. Finally, we outline an integrated, multi-pronged approach for advancing the understanding of Amblyomma ecology, species boundaries, and distribution, combining extensive field sampling, genome-wide molecular tools, pheromone studies, biological compatibility experiments, and curated voucher-linked data. This holistic framework aims to resolve taxonomic ambiguities, clarify evolutionary relationships, and guide future research on this medically and veterinary significant genus.

HIGHLIGHTS • Identifies gaps in pheromone and reproductive data for understudied species. • Highlights unresolved distributions and taxonomic ambiguities in Amblyomma. • Emphasises the lack of set standards for species delineation. • Underlines an approach to address current gaps in Amblyomma ecology, distribution and phylogenetics in southern Africa.