Acoustic mating in malaria mosquitoes: From signalling logic to vector control

Aerial mating swarms of malaria mosquitoes (Anopheles gambiae s.l.) are a common sight across tropical and subtropical regions of the world. Each dusk, 100s – or 1,000s – of males are gathering, mostly at the same locations and for years on end. Anopheline swarming is well characterised in the field and appears to be stereotypical across different species. Yet, despite its importance, little is known about the biology of the swarm and as a target for mosquito control, it has remained largely unexploited.

We will study the Anopheline acoustic courtship, which takes place in the spatially and acoustically crowded airspace of the swarm. Despite the acoustic challenges, males and females manage to communicate through changes of their flight tones. However, being ectotherms, mosquito flight tones might be prone to change with external temperature. Moreover, our preliminary data show that the time of day also impacts flight tone frequency.
In a first objective, our project will use environmental controlled incubators to carry out a detailed inventory of the acoustic signal space in Anopheles coluzzii under single- and mixed-sex conditions. In a second objective, we will conduct a complementary biophysical inventory of the mosquito flagellar ear, testing its dependency on external and internal states (e.g. temperature/mating state). Specific attention will be given to two phenomena: (i) the male-specific, self-sustained oscillations (SOs), which have been proposed as a key mechanism enabling males to identify single females within the swarm; (ii) distortions products (DPs), which result from the nonlinear mixing of pure tones (e.g. flight tones or SOs) and are thought to be key to hearing in mosquitoes.
The results from these two objectives will be integrated to formulate hypotheses regarding the underlying signalling logic, which can be tested within our setup and inform the design of novel acoustic devices or control interventions.

Project details

Vector-based Strategies

Aug 2021 — Aug 2024

$696,726

United Kingdom