Dispersal of the collembolan, Folsomia Candida Willem, as a function of age

Abstract

The tendency of Folsomia Candida to disperse varies with age. In laboratory experiments, the youngest individuals rarely moved from the release sites in dispersal trays, while the older F. Candida showed a tendency to move into more distant areas. Distance travelled is an approximately linear function of body length, and length is a power function of age in this species. The same linear relationship between dispersal and age was apparent over short (2 h) and long (24 h) dispersal periods. When food was present on the release site, the dispersive behavior of the youngest and the oldest classes was unchanged. However, the presence of food restricted travel of medium-sized springtails, many of which remained in the release site to feed. Since these young adults begin oviposition while still growing at a relatively high rate, their food requirements are higher than younger and older springtails. This change in behavior significantly altered the relationship between size and distance travelled. In natural situations, it is advantageous for the youngest individuals to remain in the area in which they hatched, where ample food and moisture are likely to be found. Because of their greater tendency to disperse, the older individuals spread their eggs over a larger area.