Antennal sensory array in the Argentine ant, Linepithema humile, and two carpenter ants, Camponotus mus and Camponotus aethiops

Abstract

Ants play a crucial role in both natural settings, impacting ecosystem functions, and in human-altered environments, where they can potentially cause harm. The Argentine ant, Linepithema humile, is recognized globally as an important invasive species, known for its ability to colonize diverse habitats and causing significant ecological and economic damage. In contrast, species of the Camponotus genus, while sharing similar food habits, typically have more restricted ranges and are also highly adapted to human-modified environments. This study serves as a foundational investigation into the antennal morphology of L. humile and two Camponotus species—one native and one from the invasive range of L. humile. We employed a systematic sampling method to analyse the distribution and relative abundance of chaetic, basiconic, and trichoidea sensilla along the last antennomere. Our results indicate that Camponotus and .L. humile have similar proportions of the sensilla analysed, with chaetic and basiconic sensilla increasing towards the tip, while trichoidea sensilla tended to decrease. Notably, both native species of Argentina, L. humile and Camponotus mus, exhibited significantly higher abundances of chaetic and trichoidea curvata sensilla compared to Camponotus aethiops from France. This study establishes a framework for future research aimed at exploring the chemosensory responses associated with these sensilla, paving the way for deeper insights into how these ants interact with their environment.