ANALYSIS OF ACCELERATION OF CHASING FLIGHT IN THE MALE HOUSEFLY
雄蝇追逐飞行的加速度分析

The acceleration of chasing fly was investigated by analyzing the traje dories of chasing flight in their free flight conditions which were recorded by a high speed film camera. The results of our experiments are as follows.1 .There is a nonlinear relation between the angular acceleration component of the chasing fly and the corresponding angular position of the leading fly in the whole visual field. It presents a good linear relation between the horizontal acceleration component of the chasing fly and the horizontal position of the leading fly when the leading fly locates in the front visual field. The pitch acceleration component of the chasing fly increases linearly with the pitch error angle increasing when the leading fly locates in the upper-half visual field and the pitch error angle is smaller than 50 degree.2.The angular velocity of the leading fly influences the corresponding acceleration component of the chasing fly also.3.The distance and/or its change between the chasing fly and the leading fly influence the magnitude of the acceleration vector of the chasing fly. A positive peak of the correlation coefficient between the magnitude of acceleration vector of the chasing fly and the distance (or distance change) of two flies appears earlier if the leading fly locates in the front visual field than that if the leading fly locates in the back visual field.4.The chasing fly uses the front dorsal part of compound eye to chase a leading female fly. The histological investigation which supports the behaviour results has shown that there are special central retinular cells in this region.5.How the parameters of the position and the velocity of the leading fly can be abstracted in the visual system of the chasing fly has been discussed.