Exuviae collections have considerable value in population studies of Odonata, but methods for standardizing collections or estimating densities and detection probabilities have been little studied. I measured sampling rates for Anisoptera exuviae and used a maximum likelihood, four-pass, depletion population estimator to standardize collections and to estimate exuvial densities and detection probabilities along 10 riverbank…
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…
Territorial behaviour and mate guarding are important components of mating systems in various insect groups, including the Odonata. This paper reports observations of male territorial behaviour associated with potential ovipositing sites, and postcopulatory, non-contact mate guarding in Petalura gigantea. This is the first unambiguous and detailed report of mate guarding in the Petaluridae. Additional observations…
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…
The reproductive behaviour of the damselfly Neurobasis chinensis (Calopterygidae) was filmed at 300 and 600 frames per second in Thailand in spring 2009. This was subsequently viewed in slow motion for detailed analysis. Altogether we observed 26 matings at two different sites. Besides visual observations of behaviour of male–female encounters at the reproductive sites, we…
Recent findings suggest that postmating prezygotic isolation (i.e. gametic barriers) could be an important factor preventing hybrid formation. Competitive gametic barriers emerge when a female is inseminated by a conspecific and a heterospecific male. We examined whether sperm proportions after double matings and copulation duration impede hybrid formation. For this, we used females of Ischnura…
Phenes raptor is one of only two petalurid dragonflies with a documented non-fossorial larval lifestyle. There have been few reported observations of larvae and their habitat, and the behaviour and ecology of this unique South American species remain largely unknown. This paper provides a review of previously published and unpublished information, and new observations on…
Behavioral data on Neotropical coenagrionids is still scanty, with very few studies on their reproductive behavior. Here we present the first description of the reproductive behavior of A. truncatum in a high density population in the Brazilian Neotropical savanna. The observations were made at a pond in an ecological reserve. Males remain at the water…
The reproductive behaviour of Libellago semiopaca was studied on a swift-flowing shallow forest stream in Brunei. Females oviposited just below the water-line, commonly in groups, only on large, firm-textured, semi-submerged logs, usually guarded by males. Both sexes were very sedentary. Suitable sites, with good illumination and deep deposits of fine gravel and leaf mulch in…
In the premontane rain forests of northwest Costa Rica, patches of secondary forest can contain high densities of large Vriesea spp. bromeliads. Such patches contain an average of 6,470 ± 1,080 (s.e.) larvae ha-1 of the bromeliad-dwelling pseudostigmatid, Mecistogaster modesta, ca 3 6× higher than larval densities that we previously reported for adjacent primary forest.