Ontogenetic Development of Spatial Orientation in First- and Second-instar Cockroach Larvae (Blattella germanica (L.), Dictyoptera)


Université de Rennes I, Laboratoire d'Ethologie, CNRS URA 373, Campus de Beaulieu, F-35042 Rennes Cedex, France.


Changes in spatial orientation related to aging were investigated during the first two instars in Blattella germanica (L). Spatial orientation was tested through shelter return under various experimental conditions in order to understand how kinesthetic path integration and visual cues intervene in the construction of this behaviour. We were able to distinguish two types of changes: experience during the first instar and maturation between instars. Young larvae need 2–3 d to develop the appropriate shelter-return behaviour when they can only use visual cues. By contrast, they can use kinesthetic path-integration cues efficiently to return to the shelter as soon as they hatch.