A comparison of structural size and condition in two female morphs of the damselfly Nehalennia irene (Hagen) (Zygoptera: Coenagrionidae)

Female colour polymorphism in coenagrionid damselflies is genetically determined for the 4 spp. so far studied. No size differences between 2 morphs have been reported. In another sp., size differences between morphs do exist but the genetic basis of the polymorphism has not been explored. In N. irene, 2 2 morphs exist: one is similar to the c? in both colour and pattern (the androchrome), whereas the other differs from the 6 (the more common gynochrome). No differences are shown in lengths of wing, femur or tarsus between androchromes and gynochromes, nor any differences in multivariate estimates of size or in wet mass corrected for these size estimates were found. The study controls for time of season, which is known to influence the size of emerging temperate damselflies. The results concur with results from other spp. where the genetic basis of colour polymorphism is known.