Oviposition site selection by Coenagrion mercuriale (Odonata: Coenagrionidae)

The aim of the study was to determine oviposition site selection in the endangered damselfly Coenagrion mercuriale in its UK stronghold and to determine hatching success of eggs. This was achieved by watching the behaviour of marked pairs from the onset of copulation to the end of oviposition and recording the number and duration of…

Oviposition site preference and egg parasitism in Sympecma paedisca (Odonata: Lestidae)

Oviposition of Sympecma paedisca was observed in eastern Kazakstan. The main oviposition substrates were living Phragmites leaves. In comparison with European and Japanese populations we propose geographic variation in the proportional use of horizontal versus vertical oviposition substrates. Ovipositing females seemed to avoid the inner parts of Phragmites stands and there was a preference for…

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…

Oviposition behaviour of Sympetrum frequens (Selys) (Odonata: Libellulidae)

Oviposition behaviour by Sympetrum frequens, a species endemic to Japan, has been observed throughout its entire breeding season, which extended for about one month after the harvest of rice. Approximately 50% of oviposition events occurred during the first week of the reproduction period. Sunny oviposition sites were preferentially selected by ovipositing pairs. The starting time…

Parthenogenetic Ischnura hastata revisited: present status and notes on population ecology and behaviour (Odonata: Coenagrionidae)

Populations of Ischnura hastata found in the Azores archipelago represent the only known example of parthenogenesis in the order Odonata. In this paper, we present results from fieldwork done on the islands of São Miguel, Pico, Santa Maria, and Graciosa, aimed at characterizing population ecology and habitat preferences of this species. Sampling of several ponds…

Effects of male harassment on females’ oviposition behaviour in Libellulidae (Odonata)

I investigated whether the level of male harassment affects females’ oviposition behaviour, such that females oviposit unguarded under suboptimal conditions and/or vary oviposition duration, dip number, dip frequency or number of oviposition site changes. The study species were the libellulids Crocothemis erythraea, Ortbetrum chrysostigma, Pantala flavescens, Sympetrum fonscolombii, Trithemis annulata and T. kirbyi ardens. Only…