Influences of Parasitic Infection and Aging on Aedes aegypti Wingbeat Frequency

Abstract

While there are thousands of species of mosquitos, only a few hundred are responsible for transmitting disease-causing pathogens; however, certain of these species, such as Aedes aegypti and Aedes albopictus, are responsible for the transmission of many urban arboviruses like dengue, chikungunya, and Zika. Due in part to the used tire trade and marine traffic, these mosquitoes can now be found on six continents and in the majority of major urban centers. Mosquitoes have been described as the deadliest animals on earth due to public health concerns; however, many questions remain regarding the ecology and behavior of mosquito as vectors of disease-causing agents. For decades, scientists have noted the acoustic signatures of mosquitoes. These unique wingbeats allow mosquitoes of the same species to locate one another for mating. In recent years scientists have shown that using sensitive acoustic devices like mobile phones, these wingbeat signatures can be used to identify mosquito species without the necessity of complex morphological identifications using taxonomic keys. In this research, I expand upon findings of unique acoustic signatures in mosquito wingbeats and address how additional aspects of mosquito biology may influence wingbeat frequencies. The aim of this work is to understand whether acoustic tools can be used not to identify mosquito species and determine whether mosquitoes are infected with pathogens of veterinary concern. Information on mosquito sex, age and other entomological indicators are essential for public health surveillance of mosquito borne diseases-causing agents. Here we confirm that wingbeat recordings can be used to identify Ae. aegypti. We present data on laboratory-reared Ae. aegypti infected with the causative agent of canine heartworm, Dirofilaria immitis, and show that while there are no clear wingbeat frequencies that can be used to identify mosquitoes infected with D. immitis from non-infected mosquitoes, wingbeat frequency can be used helpful in determining heavy burdens of infective (L3) larvae. We also show that male and female mosquitoes have unique wingbeat signatures. This contribution is important because only female mosquitoes take a bloodmeal and therefore act as vectors of disease-causing agents. We also observed a weak correlation between age and wingbeat frequencies in female mosquitoes, suggesting that wingbeats may be used to identify life history stages such as pre-feeding and post-ovipositing. Results obtained herein provide compelling justification for the integration of acoustic wingbeat recordings in public health entomology. Acoustic recordings may also aid in species identification and as a complementary tool to gather data on infection status, age, and sex.