Ontogenetic colour changes and male polymorphism in Mnais andersoni (Odonata: Calopterygidae)

Colour-based traits are widespread in flying species due to the importance of visual perception in their communication. Ontogenetic colour changes and reversible physiological colours occur in some species and are used as communication signals to conspecifics. The genus Mnais (Zygoptera: Calopterygidae) shows both genetic colour polymorphism and age-related colour changes, making challenging even the identification…

New status for Fraser’s forgotten Aciagrion approximans krishna, stat. nov. (Odonata: Zygoptera: Coenagrionidae) from the Western Ghats of India

Aciagrion Selys, 1891 is one of the taxonomically difficult and poorly known genera of Oriental damselflies. Aciargion hisopa race krishna Fraser, 1921 was described from Mahabaleshwar, Maharashtra, India. However, later Fraser (1933) doubted the taxonomic necessity of this taxon. His notion of Aciagrion hisopa (Selys, 1876) was erroneous, as evidenced by syntypes of this species…

Detection probabilities and sampling rates for Anisoptera exuviae along river banks: influences of bank vegetation type, prior precipitation, and exuviae size

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…

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…

Behaviour and body size: plasticity and genotypic diversity in larval Ischnura elegans as a response to predators (Odonata: Coenagrionidae)

Phenotypic plasticity represents an adaptive tool in organisms including odonates to cope with heterogeneous environmental conditions. However, while some odonate species can occupy various changing habitats, other species are adapted to a narrow range of environmental conditions. Commonly, behavioural modifications are applied to avoid detection and encounters with predators. But reduced behavioural activity results in…

Temperature response of growth of larval dragonflies – an overview

We review the knowledge about the thermal reaction norms of larval growth in Odonata with a focus on the temperature response function. We re-analyze literature data and present our own results on growth rates of larvae of 14 species of Libellulidae reared at different temperatures. Temperature response curves (TRC) were fitted in order to estimate…

New EPIC nuclear DNA sequence markers to improve the resolution of phylogeographic studies of coenagrionids and other odonates

While phylogeographic data provide valuable information to inform conservation plans, there are comparatively few Odonata phylogeographic studies. This lack of research is partially due to a lack of independent DNA markers with appropriate levels of polymorphism that PCR-amplify in a range of species. We followed an exon-primed, intron-crossing (EPIC) PCR strategy to develop five new,…