Dissection and internal observation of the giant tropical bont tickAmblyomma variegatum

Ticks are ectoparasites that feed on the blood of animals and humans and are among the arthropods responsible for numerous human and animal diseases worldwide. The tropical bont tick,Amblyomma variegatum, is a significant natural vector ofEhrlichia ruminantium, the causative agent of heartwater. This disease is endemic in many countries, including those in sub-Saharan Africa and certain Caribbean islands. Due to the potential of heartwater and its vector to pose an economic and health threats to non-endemic regions, they have been designated as high-consequence foreign animal diseases and pests by the United States Department of Agriculture’s Animal and Plant Health Inspection Service. Understanding the ecology and biology ofA. variegatumis critical for developing effective control methods to limit its spread to other geographic regions. A key step in this process is the isolation of tick organs and further elucidation of their functions (i.e. vector competence). However, the literature contains limited documentation of the complete internal structure ofAmblyommatick species. In this study, we describe the internal structure of unfed nymphs, partially engorged males, and unfed and partially engorged females of the tick speciesA. variegatum. The objective is to facilitate the identification and the localization organs of interest while highlighting the morphological differences between the tropical bont tick and other tick species. This foundational work will support the development of various applications following the isolation of tick organs. These findings not only deepen our understanding ofAmblyomma variegatumanatomy but also provide a critical foundation for tackling the broader challenges of tick-borne diseases and advancing vector control strategies in both endemic and non-endemic regions.