Polarized vision in the eyes of the most effective predators: dragonflies and damselflies (Odonata).

Polarization is a property of light that describes the oscillation of the electric field vector. Polarized light can be detected by many invertebrate animals, and this visual channel is widely used in nature. Insects rely on light polarization for various purposes, such as water detection, improving contrast, breaking camouflage, navigation, and signaling during mating.

Binding Molecules in Tick Saliva for Targeting Host Cytokines, Chemokines, and Beyond.

Ticks have coevolved with their hosts over millions of years, developing the ability to evade hemostatic, inflammatory, and immunological responses. Salivary molecules from these vectors bind to cytokines, chemokines, antibodies, complement system proteins, vasodilators, and molecules involved in coagulation and platelet aggregation, among others, inhibiting or blocking their activities. Initially studied to understand the complexities of tick-host interactions, these molecules have been more recently recognized for their potential clinical applications.

Ultrablack color in velvet ant cuticle.

We studied the ultrastructure of the ultrablack cuticle in , an enigmatic and visually striking species of velvet ants (Hymenoptera, Mutillidae). Using a combination of scanning electron microscopy (SEM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), and optical spectroscopy, we conducted a comprehensive analysis of the cuticle to elucidate its unique optical properties. SEM imaging provided a detailed surface morphology, while TEM provided insights into the internal structure.

Two new genera of Neotropical Dasymutillini (Hymenoptera, Mutillidae, Sphaeropthalminae): Goncharovtilla gen. nov. from Brazil and Dasyphuta gen. nov. from Panama.

Two new monotypic genera are described within the tribe Dasymutillini: Goncharovtilla Williams, Bartholomay & Lopez, gen. nov. (type species: G.

The mechanistic origin of amber pigmentation of Perithemis tenera (Say, 1840) wings (Odonata: Libellulidae) and its function in conspecific signalling.

Animal coloration serves various signaling and non-signaling functions. In damselflies and dragonflies (Odonata), such colors may not only play photoprotective and/or thermoregulatory roles but also serve as visual signals during courtship and/or agonistic interactions. Here, we analyzed the coloration of Perithemis tenera wings, a potential secondary sexual ornament, applying spectrophotometry and visual modeling to gain a deeper understanding of their color mechanisms and functions.

Hot males: thermal biology of males and females during coercive mating in water striders Gerris lacustris.

Sexual conflict theory predicts that males that adopt coercive mating strategies impose costs to females during copulation. Nevertheless, conflicting mating strategies may also affect males, although such effects on males are often neglected in the literature. Here, we seek to understand whether male water striders (Gerris lacustris) experience higher body temperatures than females during coercive mating behavior.

How to train your dragon: absolute conditioning in larval dragonflies.

Insects, despite possessing relatively small brains, exhibit noteworthy adaptive behaviors, making them intriguing subjects for understanding learning mechanisms. This study explores the learning capabilities of dragonfly larvae (Anisoptera: Aeshnidae) in conditioning experiments, shedding light on the cognitive processes that underpin their remarkable abilities. As apex predators, dragonflies play a crucial role in ecosystems, necessitating a diverse range of learning behaviors for survival and reproductive success.

Last instar larva of the critically endangered Oxyagrion franciscoi Machado & Bede, 2016 (Odonata: Coenagrionidae) from Serra da Canastra National Park.

Oxyagrion franciscoi Machado & Bede, 2016 is a critically endangered damselfly species endemic to the Serra da Canastra National Park, Brazil, a vital environmental reserve within the Cerrado hotspot for biodiversity conservation. Here we reared, illustrated, and described the last instar larva of O. franciscoi.

Vector species richness predicts local mortality rates from Chagas disease.

Vector species richness may drive the prevalence of vector-borne diseases by influencing pathogen transmission rates. The dilution effect hypothesis predicts that higher biodiversity reduces disease prevalence, but with inconclusive evidence. In contrast, the amplification effect hypothesis suggests that higher vector diversity may result in greater disease transmission by increasing and diversifying the transmission pathways.

Scorpion envenomation in the neotropical savannah: Environmental predictors and years of lost life.

Scorpion stings envenomation (SSE) is a growing medical concern in Brazil, particularly in the state of Minas Gerais, which has recorded a significant number of incidents. This study aimed to investigate the potential predictors of scorpion sting incidence and evaluate the cost-effectiveness of interventions in Minas Gerais. Generalized Estimating Equations (GEE) models were constructed using socioeconomic and environmental variables as predictors and scorpion sting incidence as the response variable.

Argia koroivarum sp. nov. (Odonata: Coenagrionidae) from Minas Gerais state, Southeastern Brazil.

Argia koroivarum sp. nov. (BRAZIL, Minas Gerais state, São Roque de Minas, Parque Nacional Serra da Canastra, 9.

A new species of Gomphoides Selys, 1854 (Odonata: Gomphidae) from the Environmental Protection Area of the Uberaba River, Brazil.

A new species of the Neotropical dragonfly genus Gomphoides Selys, 1854 (Odonata: Gomphidae) is erected from the Cerrado of central Brazil, distinguished by epiproct morphology, body coloration and wing venation. Gomphoides davi Datto-Liberato Guillermo-Ferreira sp. nov.

Detecting Darwinian Shortfalls in the Amazonian Odonata.

Among the oldest winged insects, odonates are a monophyletic order that have become important models for ecological studies because of their highly diverse reproductive behaviors and their role as top predators and bioindicators. However, knowledge on evolutionary relationships within the order is still scarce compared to other taxa, and this situation is even more complicated in areas with high biodiversity, such as in the Amazon. Here, we sought to identify knowledge gaps on Amazonian Odonata regarding three main aspects: (i) how the inclusion of Amazonian taxa affects our interpretation of the evolutionary relationships of Zygoptera and Anisoptera; (ii) the position of Amazonian taxa in the existing supertree of the Odonata; (iii) dating evolutionary divergence between nodes using fossil records; (iv) assessing whether more species-rich basins (e.

Ontogenetic colour change of a sexual ornament in males of a damselfly: female mimicry, crypsis or both?

Female mimicry by males is a widespread phenomenon in several taxa and may be involved in aggression avoidance or facilitated access to resources. In early developmental stages, female mimicry may be a mechanism involved in signalling sexual immaturity or, when coupled with strategies related to visual camouflage, may be involved in the avoidance of male-male agonistic interactions. Here, we addressed whether the delayed colour maturation of a sexual ornament in males of Mnesarete pudica damselflies might be a case of crypsis, female mimicry or both.

New Species of Entypus (Hymenoptera: Pompilidae) and notes on the natural history of some Atlantic Forest spider wasps.

We describe the new species Entypus renata, sp. nov., from the Brazilian Atlantic Forest and report on its host.

Color lightness of velvet ants (Hymenoptera: Mutillidae) follows an environmental gradient.

Color traits are highly influenced by environmental conditions along the distributional range of many species. Studies on the variation of animal coloration across different geographic gradients are, therefore, fundamental for a better understanding of the ecological and evolutionary processes that shape color variation. Here, we address whether color lightness in velvet ants (Hymenoptera: Mutillidae) responds to latitudinal gradients and bioclimatic variations, testing three ecogeographic rules: The Thermal melanism hypothesis; the Photoprotection hypothesis; and Gloger's rule.

Heteragrion/ gorbi/ sp. nov. (Odonata: Heteragrionidae) from southeastern Brazil.

Heteragrion gorbi sp. nov. (Zygoptera: Heteragrionidae) is described and diagnosed based on six ♂♂ and one ♀.

Do latitudinal and bioclimatic gradients drive parasitism in Odonata?

Prevalence of parasites in wild animals may follow ecogeographic patterns, under the influence of climatic factors and macroecological features. One of the largest scale biological patterns on Earth is the latitudinal diversity gradient; however, latitudinal gradients may also exist regarding the frequency of interspecific interactions such as the prevalence of parasitism in host populations. Dragonflies and damselflies (order Odonata) are hosts of a wide range of ecto- and endoparasites, interactions that can be affected by environmental factors that shape their occurrence and distribution, such as climatic variation, ultraviolet radiation and vegetation structure.

Revision of the genus Minagrion Santos, 1965 (Odonata: Coenagrionidae).

Endemic to Brazil, the genus Minagrion Santos, 1965 is revised for the first time. The genus contains five species, and here we establish diagnostic characters, keys and drawings for both sexes. Furthermore, we propose the synonymy of M.

The female of Epipleoneura spatulata Rácenis, 1960 (Odonata: Protoneurinae).

Here we describe the hitherto unknown female of Epipleoneura spatulata Rácenis, 1960 and present a table of characters (all illustrated) to distinguish it from other known congeneric females. We suggest that the main diagnostic character of the female of E. spatulata is the shape of posterior margin of prothorax, which is flat medially with smoothly curved erect lateral projections.

Females of the red damselfly Mnesarete pudica are attracted to more ornamented males and attract rival males.

Male calopterygid damselflies often exhibit colourful wings used during aggressive contests and courtship displays. Evidence suggests that male wing coloration is a secondary sexual character assessed by males and females to identify male quality. In some species, males adopt a lekking strategy, where females visit exhibition arenas and choose the best mate.