This CT scan is a close-up of the structural features of a male mosquito’s antennae. Purdue University researchers are studying these features to see if they could inform the design of acoustic sensors. (Credit:
Purdue University image/Phani Saketh Dasika)

WEST LAFAYETTE, Ind. — Most of us know mosquitoes primarily as unwelcome summer guests, but these tiny insects possess extraordinary sensory abilities that could inspire tomorrow’s technology. A recent study from Purdue University reveals how mosquito antennae function as sophisticated sound detectors that could someday inspire sensors for earthquake detection and disaster response.

Unlike humans who hear through ears, mosquitoes hear through their antennae, those delicate, feather-like structures extending from their heads. What makes this remarkable is how well mosquitoes hear specific sounds despite the constant noise created by their own beating wings. It’s a bit like being able to follow a whispered conversation while using a leaf blower.

The research team, published in Acta Biomaterialia, studied two mosquito species with different hearing needs: Aedes aegypti, which uses sound to find mates, and Uranotaenia lowii, which tracks frog calls to locate its next blood meal.

“By modeling and contrasting the response of the antenna of species of mosquito using sound for different purposes, hearing mates or eavesdropping on frogs, we were able to tease apart features modulating hearing sensitivity and tuning,” says study author Ximena Bernal, a professor of biological sciences at Purdue University, in a statement. “Understanding how these structures work is the first step toward developing acoustic sensors inspired by their sensitive antennae.”

For male Aedes aegypti mosquitoes, finding females is critical for reproduction. They locate potential mates by detecting the distinctive sound of female wing beats amid the buzzing of other males in the swarm. Their antennae have evolved to be extremely sensitive to these specific frequencies.

Female Uranotaenia lowii mosquitoes, on the other hand, need to track down frogs for blood meals. They’ve developed antennae that can pick up frog mating calls across relatively long distances, even with their own wings beating.

The research team created detailed computer models to understand how these antennae work. They found that mosquito antennae aren’t just passive receivers but sophisticated structures finely tuned to specific frequencies.

“Using advanced micro-CT imaging to create high-fidelity CAD models for finite element analysis, we found that the architectural features of mosquito antennae enable species- and sex-specific acoustic target detection, even amid nontarget signals like their own wingbeats,” says study author Phani Saketh Dasika. “Our findings also suggest that mosquito antennae are capable of detecting a broader range of frequencies than previously thought, though not all of these may be actively utilized.”

A mosquito antenna consists of a central shaft (the flagellum) made up of segments of different sizes stacked together. From these segments extend thin sensory hairs called fibrillae that radiate outward. The interplay between these structures creates such effective hearing.

The team discovered that these sensory hairs dramatically boost sensitivity. For male Aedes aegypti, the presence of hairs increased sound sensitivity by an astounding 90 times compared to a basic rod-shaped antenna. Female Aedes aegypti experienced a seven-fold increase, while male and female Uranotaenia lowii showed 10-fold and nine-fold increases, respectively.

This boost comes from the increased surface area that captures sound waves—similar to how a larger solar panel captures more sunlight. But sensitivity alone isn’t enough for effective hearing.

The researchers also found that the tapering shape created by variable segment sizes acts as a natural frequency filter. This helps males focus on female flight tones and helps Uranotaenia lowii females detect frog calls. Each type of mosquito antenna is precisely tuned to frequencies that matter most for their survival and reproduction.

When tested with recordings of actual mosquito wingbeats and frog calls, the results were striking. Male Aedes aegypti antennae could detect female wingbeats even at very low volumes despite the noise from their own wings. Similarly, female Uranotaenia lowii could pick up frog calls through their own wingbeat interference.

This specialization wasn’t universal, though. When exposed to sounds they didn’t evolve to detect (like frog calls for Aedes aegypti females), the antennae only responded well at higher volumes and otherwise mainly detected their own wingbeat frequency. The research team is now working to recreate these antennae through 3D printing, using different materials and sizes to test frequency responses.

“Taking inspiration from nature and using it to advance scientific research has been a core feature of engineering since the very beginning,” says study author Pablo Zavattieri from Purdue’s College of Engineering. “We’re still in the early stages but we’re pretty optimistic that we’ll at least learn a great deal.”

The potential applications go well beyond understanding mosquitoes. The principles behind these antennae could lead to new technologies for acoustic sensing, smarter noise-canceling materials, and specialized sensors for detecting subtle vibrations.

“Imagine urban environments equipped with bio-inspired sensors, akin to ‘big ears,’ capable of discerning specific sounds amid the hustle and bustle of city life,” says Zavattieri. “In times of crisis — such as earthquakes or other disasters — these sensors become invaluable, swiftly detecting faint signals of distress and guiding rescue efforts to those in need.”

For disease-carrying mosquitoes like Aedes aegypti, this research might even lead to better control methods. By understanding how they find mates through sound, scientists might develop ways to disrupt this communication and reduce mosquito populations without relying solely on insecticides.

As for Uranotaenia lowii, their ability to eavesdrop on frog calls shows how evolution can produce highly specialized sensory systems. These mosquitoes have essentially tapped into the frogs’ communication channel for their own benefit, a remarkable adaptation that illustrates the interconnectedness of sensory systems in nature.

That annoying whine of a mosquito flying past your ear represents one of nature’s most sophisticated acoustic systems, a flying marvel of biological engineering perfected over millions of years. While that sound might make you reach for the swatter, its mechanics could inspire new technologies in acoustic sensing, from improved noise cancellation to potentially aiding in disaster response.