The Antenna Base Plays a Crucial Role in Mosquito Courtship Behavior

Abstract

Mosquitoes are vectors of pathogens that cause diseases like malaria, dengue fever, yellow fever, chikungunya and Zika. For mosquito control it is crucial to understand their hearing system, as mosquitoes’ courting behavior is mostly auditory. Many nonlinear characteristics of the mosquito hearing organ have been observed through behavioral studies and neural measurements. These enable mosquitoes to detect and synchronize to other mosquitoes. Many hypotheses concerning the role of the flagellum and the fibrillae of the antenna in mosquito hearing have been made, and neural processes have been considered as the origin of the nonlinearities. In this study we introduce a geometric model based on the morphology of the mosquito antenna base. The model produces many of the observed nonlinear characteristics, providing evidence that the base of the antenna plays a crucial role in mosquito hearing. Even without neural processing, the antenna response to sound produces behaviorally relevant cues that can inform about the presence, location, and sex of other mosquitoes.

Mapping the auditory space ofCulex pipiensfemale mosquito in 3D

“…As sound fields are usually strongly divergent close to small sound sources, bilateral particle velocity receivers such as the mosquito's antennae may experience vastly different vector fields depending on the distance from the sound source, which may affect their ability to extract directionality data from the sound, i.e., the velocity field may or may not directly point to the sound source (Robert, 2005). For the sake of simplicity, one may assume that each antenna is functionally omnidirectional, and only the inter-antennal amplitude differences (IADs) based on the nonlinearities that produce difference frequencies are used to provide the localization cues (Ziemer et al, 2022). Although the modelling experiments in that study demonstrated that IADs in mosquito may be sufficient for the task, we consider it quite unnatural that the information on directionality that is mapped in the activity of the numerous auditory units of the JO may be lost on its way to the brain, even if it does not allow to unequivocally discriminate between the two opposite directions.…”

Mapping the Auditory Space of Culex pipiens Female Mosquitoes in 3D

“…One may assume that each antenna is functionally omnidirectional and only the inter-antennal amplitude differences (IADs) are used to provide the localization cues, thus converging the functionality of particle velocity receivers to that of pressure receivers. Although the modelling experiments demonstrated that IADs in mosquito may be sufficient for the task of the sound localization [ 9 ], the main evidence in favour of a more complex mechanism of auditory directionality in mosquitoes is an extremely large number of sensory neurons in the JO [ 10 ], compared to insect tympanal ears [ 11 ].…”