How mosquitoes hover after tripling their bodyweight with blood

Mosquitoes are a nuisance. The female insects feed on human blood, often going undetected until the itchy raised bump on the victim’s skin reveals their visit. They can also spread disease as they fly from person to person for their next meal. Yet the mosquito’s stealthy flight is a feat of biology, keeping them aloft after a hefty snack.

Liu and Du investigated the mosquito flight dynamics to understand how they hover before and after feeding. Using high-speed cameras, they captured the insects in action and used computational fluid dynamics to analyze the wing-flapping aerodynamics.

“Mosquitoes are well-known for their voracious blood-feeding habits, where a single feeding can amount to several times their own body weight,” said author Gang Du. “Despite this, they demonstrate a remarkable ability to effectively evade their victim’s attempts to swat them once they are noticed, prompting our nuanced exploration of the aerodynamic characteristics after blood-feeding.”

The researchers photographed each mosquito as it fed on mouse blood. After feeding, they weighed the mosquitos and measured the shape of the wings. They fit their data into a computational fluid dynamics model that allowed them to understand the observed flight dynamics.

“From the standpoint of flapping-wing kinematics and aerodynamics, mosquitoes exhibit distinct characteristics compared to any other insect group, marked by a relatively high wing-flapping frequency, typically ranging from several hundred Hertz up to one thousand Hertz, and a small wing stroke amplitude of approximately 50 degrees,” said Du.

After feeding, mosquitoes increase their stroke amplitude and velocity and change the flip angles.

The researchers will next investigate mosquito forward flight.

Source: “Effects of blood-feeding on mosquitoes hovering kinematics and aerodynamics,” by Yanpeng Liu and Gang Du, Physics of Fluids (2024). The article can be accessed at https://doi.org/10.1063/5.0198040 .