Labelling Locusts with Radioactive Isotopes

Abstract

FOLLOWING successful attempts at marking Lepidopterous larvæ with radioactive sulphur with the object of investigating population dynamics, larval death-rate, and dispersal¹, an opportunity presented itself of applying similar principles to locusts (Locusta migratoria L. and Locustana pardalina Walk.). Accordingly, a series of laboratory experiments was carried out on (a) locust hoppers and (b) locust adults. In each case, phosphorus-32 was given and feeding permitted for twenty-four or forty -eight hours, and this was followed by their return to normal food; thereafter, each having been anæsthetized by carbon dioxide, the individual counts per minute were recorded with a Geiger counter, as also were those for their excreta and exuviæ.