Geographical variation in size of the three final stadia of Cordulegaster boltonii (Donovan, 1807) larvae in the Iberian Peninsula (Odonata: Cordulegastridae)

A two-variable analysis of male and female Cordulegaster boltonii larvae (head width and hindwing sheath length) in specimens from five Iberian populations was carried out with the objective of ascertaining whether these traits differ between populations. The results indicate that the southernmost population (Los Alcornocales, Andalusia) have larger sizes for both variables and a lower growth rate between the penultimate and final stadia. Winter water temperatures, which may cause a longer arrest of larval growth in northern populations, and possible differences in the number of larval stadia could be the origin of the size divergences.