Correlations between stationary measurable parameters of wing movement and aerodynamic force production in the blowfly (Calliphora vicina R.-D.)

Abstract

With the aid of a mechanical aerodynamic two component balance, stroboscopes and photographic projections, the following dynamic and kinematic parameters were determined from short periods of stationary flight recorded in tethered blowflies which flew for several hours in a wind tunnel: weight, lift, flight speed, wing-beat frequency, nine angles characteristic for right and left wing-beat positions and a value characterizing the angle of the stroke plane. The data were subjected to a correlation analysis; the total correlation coefficients and the first order partial correlation coefficients were calculated with a significance of 5% and 1% respectively. The correlation between wing-beat frequency and lift was found to be strongly positive. Frequency, lift and flight speed are positively correlated with the sum of the wing-beat angles. Although under the given experimental conditions a significant tendency towards compatible adjustment has been demonstrated lift and thrust can be controlled independently in individual cases. Negative correlations of wing-beat angles of the right and left wing are generally caused by shifting the lower turning points and indicate a neuromotoric counter action of the two wings during turning reactions. A decreasing wing-beat amplitude is often coupled with an increase of the mean stroke plane angle. Numerous other correlations and detailed descriptions are given and compared to functional morphological and neuromotoric data.