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…

Local extinctions and range contraction of the endangered Coenagrion mercuriale in North Africa

Freshwater biodiversity is currently threatened worldwide. In North Africa, 24.4% of Odonata are regionally threatened with extinction. In this region, freshwater resources are particularly scarce and an increasing shortage of water is expected. To better understand the current threats to the endangered North African damselfly Coenagrion mercuriale we updated information on extinct and extant populations…

Melanic individuals in color polymorphic Enallagma damselflies result from phenotypic, not genetic, variation

Genetically determined color polymorphisms have a long history in the study of evolutionary change acting on populations. The Odonata exhibit relatively high levels of sex-specific color polymorphisms in mature adults. In Ischnura and Coenagrion, female-specific polymorphisms are known to be controlled by Mendelian genes. Nearly half of Enallagma species have polymorphic females, but the inheritance…

Behavior of the Amazonian damselfly Chalcopteryx scintillans McLachlan (Zygoptera: Polythoridae) and comments on its morphological distinction from C. rutilans (Rambur)

Polythorid damselflies are Neotropical stream dwellers, whose behavior has rarely been recorded. Here we describe the territorial and courtship behavior of Chalcopteryx scintillans McLachlan, an Amazonian damselfly with shiny copper-colored hind wings. Territorial behavior consists of aerial contests, when males engage in threat displays and mutual pursuits in ascending and rocking flights. During courtship, males…

Odonata of Curaçao, southern Caribbean, with an update to the fauna of the ABC islands

A three-year field study (January 2011–December 2013) of the Odonata of Curaçao, supported by photos and exuvial collections, recorded a total of 21 species from the island, almost doubling its previously known fauna. The lists of Odonata known from Aruba and Bonaire were also updated by specimen and photo records, and 24 species are now…

Are community patterns in flight height driven by antagonistic interactions?

Large libellulid dragonflies often fly higher than smaller libellulids. We hypothesized that this size-related pattern in flight height might be caused by aggressive displacement. We tested this hypothesis by using a 30 m “dragonfly zip-line” to reel dead dragonfly decoys of four species of different sizes (Erythemis simplicicollis, Libellula incesta, Pachydiplax longipennis, and Perithemis tenera) along…

Variation in fluctuating asymmetry among nine damselfly species

Fluctuating asymmetry (FA), measured as random deviations from bilateral symmetry, likely results from developmental disturbances by internal or environmental stresses. However, comparisons of FA in single damselfly species (Odonata: suborder Zygoptera) from stressed environments have often been inconclusive. We measured levels of FA among multiple species of damselflies from the same environment to determine the…

Two new species of Pyrrhargiolestes, with a key to the males (Odonata: Argiolestidae)

Two new species belonging to the endemic New Guinea genus Pyrrhargiolestes are described from Papua New Guinea: P. lamington sp. nov. (holotype: Mount Lamington, Oro Province, dep. in RMNH) and P. yela sp. nov. (holotype: Rossel Island, Milne Bay Province, dep. in USNM). The presumed male of P. aulicus is described for the first time….

The levis group of Orthemis revisited: a synopsis including a synonymy and description of six new species of Orthemis from South America (Odonata: Libellulidae)

The levis and ferruginea groups of Orthemis are redefined. Six new species of Orthemis are described: O. aciculata sp. nov. (♂ holotype: Surinam, Para Dist., road near forest, Zanderij I (5°32′ N, 55°10′ W), 17 January 1957, leg. J. Belle [RMNH]), O. celata sp. nov. (♂ holotype: Brazil, Pará State, Rio Gurupí, Canindé (0°30′57′ ′…