Alternative oviposition tactics in Zygonyx torridus (Kirby) (Odonata: Libellulidae): modes and sequential flexibility

Zygonyx torridus inhabits waterfalls, rapids and riffle sections. Males patrol over these sites. After copulation the partners perform an extensive search while flying in tandem over a wide range. Behavioural studies in Mauritius 1997 and 2014 showed that there is considerable plasticity in oviposition behaviour. Three main modes could be distinguished: (A) egg-laying in tandem…

Hybridization between Calopteryx splendens and C. haemorrhoidalis confirmed by morphological and genetic analyses

Hybridization between Calopteryx haemorrhoidalis and any of its congeners has not been reported until now. We observed spontaneous matings between male C. splendens and female C. haemorrhoidalis at a locality in Central Italy, together with some putative hybrid individuals that had a mixed phenotype. Here, we report the morphological and molecular characterization of five suspected…

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…

Biting in dragonfly fights

Slow motion films of fight behaviour of five different species of Odonata were analysed. In all cases biting played a major role. The biting duration depended on the duration of a stable connection between the two opponents. Sitting odonates showed much longer biting than those that were flying. In fights of Anax junius and Calopteryx…

An emergence study of Petalura gigantea (Odonata: Petaluridae)

Emergence studies in Odonata provide information on the behaviour, ecology and fundamental demographic parameters in population studies. This paper reports on a study of sex ratio at emergence, pattern and duration of the emergence season, and potential cohort splitting in Petalura gigantea. Sex ratio at emergence varied among years, habitat patches and swamp types. Across

Macromidia donaldi pethiyagodai subsp. nov. from Sri Lanka (Odonata: Corduliidae)

Macromidia donaldi pethiyagodai subsp. nov. (holotype ♂: Sri Lanka, Ratnapura District, near Kudawe, 6.26°N, 80.25°E, 03 July 2007; paratype ♀, same location, 17 April 2008, to be deposited in the Sri Lanka National Museum, Colombo) is described and figured. Its phenotype differs from that of M. d. donaldi from India. This is the first record…

Odonata colour: more than meets the eye?

Interpretations of behavioural visual cues, based on human perception of colour, may mislead because of the difference in our visual range compared to other animals. Investigations into ultraviolet (UV) reflectance have shown that this can be an important mode of communication in many animals. The present study focused on 10 species of British Odonata. Digital