Distribution spatiale des larves de trois Anisoptères (Aeshnidae, Libellulidae)

The interspecific and ontogenetic variations in the larval distribution of Aeshna cyanea, Anax imperator and Libellula depressa were estimated on the basis of monthly samples in a pond in Brittany, France. The aeshnids co-occurred, but L. depressa usually inhabits the shallow parts only. The younger A. cyanea instars tend to congregate. In the FO and F-l aeshnid instars, the spatial overlap index decreases from April to May. No relationship between larval age and water depth could be evidenced.