Abstract (auf Englisch):
Both mosquitoes and fruit flies use sounds to identify, locate, and communicate with, their mating partners (1). In mosquitoes, the corresponding signalling takes place during mid-flight, often within large, male-dominated swarms.During the acoustic interactions, the mosquitoes’ wingbeats - inevitable sound emissions of flying mosquitoes – are modulated and co-opted as courtship signals. Fruit flies also produce sounds with their wings. In contrast to mosquitoes, however, flies stay ‘grounded’ during their acoustic courtship: Males chase females whilst unilaterally (or occasionally bilaterally) flapping their wings to produce species-specific courtship songs.
On the sensory side, both flies and mosquitoes use their antennae as external sound receivers. The antennal receivers transmit sound-associated forces to specialized mechanoreceptor neurons within Johnston’s Organ (JO). JO is a multicellular chordotonal organ (ChO) that forms part of the flight control machinery across insects. In both flies and mosquitoes, JO is an active sensory organ in that it injects mechanical energy into sound-induced stimulation, that means it displays energy gain.
The Drosophila JO contains ~500 neurons. In male mosquitoes, however, it can harbour up to 16,000 mechanosensory neurons making it the largest and - most sensitive- ChO in the insect kingdom, exceeding energy gains (and displacement sensitivities) of vertebrate inner ear hair cells by a factor of ~ 100 (2).
This seminar will present some recent results, and emerging hypotheses, on the function, sensory ecology and evolution of hearing and acoustic communication in Dipteran insects. The seminar will explore the auditory systems of (Drosophila) fruit flies, as well as those of three biomedically important mosquito vector species (the malaria mosquito Anopheles gambiae, the yellow and dengue fever mosquito Aedes aegypti and the West Nile fever vector Culex quinquefasciatus). Using the fruit fly ear as a model, the sensory performance of male and female ears will be compared across the taxa, in an attempt to reconstruct the auditory (and reproductive) ecology of Dipteran insects from the biophysical operation of their ears.
1.Albert JT, Kozlov AS. “Comparative Aspects of Hearing in Vertebrates and Insects with Antennal Ears”. Current Biology 26: R1050-R1061 (2016)
2.Su MP, Andrés M, Boyd-Gibbins N, Somers J, Albert JT. “Sex and species specific hearing mechanisms in mosquito flagellar ears”. Nature Communications 9: 3911 (2018)