Active hearing process in mosquitoes

Nov 20, 2009
This is a mosquito hearing organ. Credit: University of Bristol

A mathematical model has explained some of the remarkable features of mosquito hearing. In particular, the male can hear the faintest beats of the female's wings and yet is not deafened by loud noises.

The new research from the University of Bristol is published in the Journal of the Royal Society: Interface.

Insects have evolved diverse and delicate morphological structures in order to hear the naturally low energy of a transmitting sound wave. In , the hearing of acoustic energy, and its conversion into neuronal signals, is assisted by multiple individual sensory units called scolopidia.

The researchers have developed a simple microscopic mechanistic model of the active amplification in the Tanzanian mosquito species Toxorhynchites brevipalpis.

The model is based on the description of the antenna as a forced-damped oscillator attached to a set of active threads (groups of scolopidia) that provide an impulsive force when they twitch. The twitching is controlled by channels that are opened and closed if the antennal oscillation reaches critical amplitude. The model matches both qualitatively and quantitatively with recent experiments: spontaneous oscillations, nonlinear amplification, hysteresis, 2:1 resonances, frequency response, gain loss due to hypoxia.

The also generate new hypotheses. In particular, the model seems to indicate that scolopidia located toward the tip of the Johnston's organ are responsible for the entrainment of the other scolopidia, and that they give the largest contribution to the mechanical amplification.

Dr Daniele Avitabile, Research Assistant in the Bristol Centre for Applied Nonlinear in the Department of Engineering Maths, said: "The numerical results presented also generate new questions. In our description of the system, for instance, all threads have the same material properties, but their impact on the dynamics of the antenna varies according to the spatial location of the threads: intuitively, an external thread induces a much larger torque than an internal one.

"However, the true physiology of the threads is more complex, due to the curved arrangement of Johnston's organ, and further research into the effect of the subsequent mechanical variation of each thread needs to be carried out."

Source: University of Bristol (news : web)

Explore further: Local education politics 'far from dead'

add to favorites email to friend print save as pdf

Related Stories

How to catch a mosquito

Nov 09, 2006

Male mosquitoes increase their chances of mating with a passing female by enhancing their ability to hear her flying past. Much like the human ear, the mosquito ear is able to amplify the sounds it hears, making ...

How a locust's eardrum could lead to tiny microphones

Mar 31, 2006

Being able to hear the smallest of noises is a matter of life or death for many insects, but for the scientists studying their hearing systems understanding how insect ears can be so sensitive could lead to ...

Why spiders' silk threads don't twist

Mar 30, 2006

Unlike a mountain climber swinging from a rope, a spider suspended from its silk thread hardly ever twists. Although the flexibility and strength of a spider’s dragline outperforms the best synthetic fibres, ...

Recommended for you

Local education politics 'far from dead'

20 hours ago

Teach for America, known for recruiting teachers, is also setting its sights on capturing school board seats across the nation. Surprisingly, however, political candidates from the program aren't just pushing ...

First grade reading suffers in segregated schools

20 hours ago

A groundbreaking study from the Frank Porter Graham Child Development Institute (FPG) has found that African-American students in first grade experience smaller gains in reading when they attend segregated schools—but the ...

Violent aftermath for the warriors at Alken Enge

21 hours ago

Denmark attracted international attention in 2012 when archaeological excavations revealed the bones of an entire army, whose warriors had been thrown into the bogs near the Alken Enge wetlands in East Jutland ...

Why aren't consumers buying remanufactured products?

23 hours ago

Firms looking to increase market share of remanufactured consumer products will have to overcome a big barrier to do so, according to a recent study from the Penn State Smeal College of Business. Findings from faculty members ...

Expecting to teach enhances learning, recall

23 hours ago

People learn better and recall more when given the impression that they will soon have to teach newly acquired material to someone else, suggests new research from Washington University in St. Louis.

User comments : 0