Alternative oviposition tactics in zygonyx torridus (kirby) (odonata: libellulidae): modes and sequential flexibility

Abstract

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 during flight; (B) the female placing the eggs while dipping in flight without physical contact with the male; and (C) the female placing the eggs when settled without physical contact with the male. On several occasions two modes, and in a single case all three types, were observed within one oviposition sequence. In odonates, such a high degree of plasticity in reproductive behaviour was not reported previously.