Rubidium marking of the rice pests Nilaparvata lugens (Stål) and Sogatella furcifera (Horváth) (Hemiptera: Delphacidae) for field dispersal studies

Abstract
The method and evaluation of a field application of rubidium chloride for the purpose of a mark-and-recapture experiment are described. In the Philippines, populations of the rice pests Nilaparvata lugens (Stål) and Sogatella furcifera (Horv.) were successfully marked by a foliar spray of rubidium chloride plus surfactant applied to a rice field at 1·03 g/hill. Individual insects marked with rubidium, which were easily distinguishable from unmarked individuals for at least seven weeks, were generated at this dose level, and even after one year elevated rubidium levels could be detected in pooled samples. Other phytophagous and entomophagous insects also became marked.