A preliminary study on female-limited colour polymorphism in Lestes sponsa

Female-limited colour polymorphisms are widespread in Odonata, usually showing an androchrome and one or more gynochromes. Androchromes have been hypothesized to function as male mimics with a consequent decrease of male harassment, although males may also learn to recognize the different female colour morphs. In the Eurasian damselfly Lestes sponsa, the occurrence of two female…

Group oviposition in three platycnemidid species (Odonata: Platycnemididae)

The European Platycnemis acutipennis and P. latipes and the African Mesocnemis singularis aggregate during oviposition. Choice experiments show that, in all three species, groups develop because tandems preferentially land where conspecifics already show oviposition behaviour. Just a single motionless male in the typical vertical position of a tandem male stimulates aggregation and oviposition behaviour in…

Repeated predation of Odonata by the hornet Vespa crabro (Hymenoptera: Vespidae)

Predation of aggregated, ovipositing tandems of Sympetrum sanguineum and S. vulgatum by the hornet Vespa crabro was observed in Belarus. The same species of hornet was seen killing territorial males and copulating females of Calopteryx haemorrhoidalis in Italy. Numerous remains of these odonates at the oviposition sites suggest that attacks occur frequently. A short review…