Estimating Movement of the Processionary Caterpillar Ochrogaster Zunifer Herrich‐Schäffer (Lepidoptera: Thaumetopoeidae) between Discrete Resource Patches

Larval dispersal is an important component of the population ecology of many lepidopteran species. However, measuring dispersal in the field is notoriously difficult, labour‐intensive and often expensive. An indirect method for estimating larval dispersal is outlined. Frass and exuviae of processionary caterpillars, O. lunifer, present at the base of host trees are used to estimate the number of migration events to and from trees in a season. Estimates using this method compared favourably with estimates from a mark‐recapture method. The technique can be used to estimate rates of dispersal at a large number of localities by a single researcher, allowing dispersal to be compared between different populations