Pour Une Théorie de la Description Chétotaxique Chez Les Collemboles

Abstract

In this work we try to show that chaetotaxic description of Arthropods can follow a theoretical process. We consider that the setae of one body area, when they are studied using a pool of specimens of one species of one instar and of one sex, constitute a chaetotaxic set. The chaetotaxic sets, through the medium of their items, can also be the matter of comparisons (between species, instars, etc.). Three approaches are proposed for studying these sets. At first, the setal characteristics are based on morphology (even on ultrastructure). The second approach uses the recognition of some geometrical setal orders. The third one establishes the existence of links between setae or groups of setae, as a malter of fact a change in one item is simultaneous of a change in another one. and that repetitively. At last, we propose a general proceedure for constructing chaetotaxic patterns. Chaetotaxy often off ers good tools for ontophylogenetic studies.