Path integration in cockroach larvae, Blattella germanica (L.) (insect : Dictyoptera): Direction and distance estimation
Résumé
The question of how an insect finds its way between foraging areas and its shelter has been investigated in cockroaches, Blattella germanica. Our aim was to demonstrate that they integrate the characteristics of their outward trip to estimate direction and distance, which enable them to return to their shelter, relying on path integration mechanisms using kinesthetic cues. The return path pattern was characterized by a nearly linear oriented-to-the-goal trajectory, an arrest, and a systematic search at a much slower speed. The arrest position indicated that the insect's home vector was back to zero and that it was the estimated shelter position. If the shelter failed to be at the arrest position, cockroaches started a nonrandom systematic search directed mainly around the arrest. They looped back and forth around the arrest position and increased the size of their loops with time. The pattern of this search seems to be an ubiquitous trait in insects.