Dr. Natasha Mhatre
Postdoctoral Fellow
Department of Biological Sciences
University of Toronto at Scarborough

Abstract: Oecanthus henryi is a tree cricket and belongs to the phylogenetically most ancient group of insects known to use sound for attractign and findina mates. Among crickets, males sing and females find them using these songs. The two most important things that limit the distance over which such mate attraction is possible are the loudness of the male song and female sensitivity. Most crickets use a simple, ‘passive’ solution for this problem. Mechanical resonance is the tendency of a system to oscillate with greater amplitude at some frequencies than at others. Typically, the structures that males use for song production (wings) and that females use for auditory reception (ears) resonate at the same frequency. Thus they are both loudest and most sensitive at the same frequency, thus maximising mate attraction distance.

In my talk, however, I will show how insects are not limited to passive solutions. O. henryi males use an active behavioural strategy. They manufacture a near-optimal tool, an acoustic baffle, to make themselves louder than their passive structural solution would ever allow them to be. Not to be outdone, O. henryi females, have a physiological active amplification system in their ears, which they exploit to create frequency sensitivity that the passive structure does not possess. Both mechanisms increase the range of mate attraction much further than the passive system, but more importantly underline the wealth of biophysical innovation yet to be discovered even among ‘simple’ organisms.

Behaviour – Biophysical Innovation – Insects