PHONOTAXIS AND ACCURACY OF ACOUSTIC ORIENTATION IN THE BUSHCRICKET (DERACANTHA ONOS)
螽斯(Deracantha onos)的趋声性与定位精度

Phonotactic movements of female bushcrickets (Deracantha onos) towards the calling song of a conspecific male were investigated. Based on the phono-tactic tracks taken by female bushcrickets the accuracy of acoustic orientation was determined. Only the calling song of a conspecific male can elicit a pho-notactic response of the female bushcricket. The walking velocity increased by about ten times as compared with non-phonotactic walking. The pattern of pho-notactic approaches was zigzag. The polar orientation diagram can describe the directionality of phonotactic movements of the females. With calling song presentation the weight for zero degree with respect to sound source was maximal, ranged between 0.34 and 0.69. The azimuth of the calculated centroid for the diagram represents the accuracy of acoustic orientation and amouts to less than 3°. The mean walking directional angle of phonotactic approaches by the females was 0.4° with standard deviation of about 10°.