The Pick-up of Spray Droplets by flying Locusts

Abstract

Measurements of the Horizontal Equivalent Area (HEA) of flying locusts and the toxic efficiency of Mk. IV DNC solution, as a function of spray droplet size, have been made using Schistocerca gregaria (Forsk.) flying “ naturally ” in a wind tunnel. The experimental conditions, including visual stimuli, for “ natural ” flight were determined by means of a flight balance. The observed values of locust airspeed varied from 2·5 to 6·5 metres per second with a mean value of about 3·2 metres per second.