Sound reception and radiation in a small insect

Natasha Mhatre , Fernando Montealgre-Z , Rohini Balakrishnan , Daniel Robert

Insects are small; this is a fact of their life. In some contexts this is an advantage, such as insects do not injure themselves through the effects of gravity. In other contexts this is a disadvantage, especially in the context of sound production and reception. The wavelengths of sound that insects such as crickets produce and receive are several times larger than their body size. For sound production, this is particularly challenging and inefficient, as sub-wavelength radiation (size to lambda ratio > 1:100) requires great energy expenditure to produce sufficient sound pressure. In receiving sound, they face the reciprocal problem and are inefficient receivers. In addition, because of their size they cannot rely on cues other animals use to detect the direction of sound. Nonetheless, sound is extremely important to these insects as they use it for mate attraction and to evade predators. We investigate this problem by combining the technique of microscanning laser Doppler vibrometry with finite element modelling; and explain some of the biomechanical tricks a tiny tree cricket uses to overcome the disadvantages of size.

Mots clés: insects; biomechanics; vibrometry; FEM

Domaines: Acoustique [physics.class-ph]

Natasha Mhatre, Fernando Montealgre-Z, Rohini Balakrishnan, Daniel Robert. Sound reception and radiation in a small insect. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00811362⟩