Dr. Moira van Staaden
office: LSC 304
phone: 2-0341
Email: mvs@caspar.bgsu.edu
o The cricket model: from Franz Huber to Barbara Webb
- one of the first model systems in neuroethology
- field behavior > lab physiology > recording in freely
moving animals
- simple system with a conspicuous behavior
o Contribution of animal communication studies
- adaptive function of behavior
- evolution of behavior
- signal generation by senders
- signal detection and analysis by receivers
o Cricket robot (Barbara Webb)
- electronic circuit to model cricket ears
- simulated spiking neuron network to process the signal
- Why bother?
- less complex neural controller performs as well as real female
- explore mechanisms controlling recognition & choice behavior
o Behavioral task of intraspecific communication
- to ensure individuals recognize & mate exclusively with
own species
signals - must conform to species-wide pattern
- the product of highly stereotyped FAP's
- be received, distinguished & recognized, localized
oApproaches
- physiology in lab
- physiology in field
- high tech robots
oAuditory examples
- humans are bad at other modalities
- sound is accessible (electronic recording and analysis equipment)
- easily synthesize sounds for use in behavioral and neurophysiological
experiments
Order Orthoptera
Family Tettigoniidae (bush crickets)
Family Gryllidae (field crickets)
Family Gryllotalpidae (mole crickets)
Female has 2 problems:
1. recognize the incoming signal as the call of a conspecific
male
2. locate the source of the sound
o Phonotaxis - motion with respect to the source of
a sound
intraspecific - primarily positive
interspecific - primarily negative
Elements of Calling Song
[FIG 1] Teleogryllus commodus (field cricket) vs Gryllotalpa
australis (mole cricket)
o Sound period/Carrier frequency
- interval from given point on one wave to equivalent point on
the next
- measured in thousands of cycles per second (kHz)
o Cycle period
- the interval between the onset of one syllable and the onset
of the next
- expressed in Hz as the syllable repetition rate
o Absolute duration
o Duty cycle - the proportion of each cycle period occupied by
sound
Sympatric species
Call times differ - australis at dusk, commodus
later
Calling songs differ:
- form
- syllable repetition rates (70 australis vs 25 commodus, at 23
oC)
- carrier frequency (2.5 vs 3.8 kHz)
Sound production by stridulation
Insects hard exoskeleton >> many different mechanisms
of stridulation
e.g. bladder grasshoppers and crickets use file and scraper mechanism
[FIG 2]
Same as flight muscles but
- accessory muscles hold wing hinge at different angle
- convert mechanical energy > acoustic energy
- concentrate energy into certain range of sound frequencies
Fundamental frequency = the rate at which scraper strikes the teeth
Harmonics - higher frequencies, simple multiples of fundamental, amplitudes decrease with increasing frequency
Stridulation mechanism distributes acoustic energy over a wide range of frequencies
Sound emitted modified by presence of a coupled resonator (harp)
- an object with strong tendency to vibrate at a particular frequency
(the resonant frequency) as a consequence of its physical properties
- test with laser vibrometer
- resonant frequency generally corresponds to CF of calling song
[FIG 3]
Last modified: 00/04/028