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1.
Zootaxa ; 5169(1): 26-30, 2022 Jul 27.
Article de Anglais | MEDLINE | ID: mdl-36101257

RÉSUMÉ

Two new species of Oxyethira from Brazil are described: Oxyethira (Dampfitrichia) jiquitaia sp. nov., and Oxyethira (Tanytrichia) librina sp. nov. Illustrations of male genitalia are provided with each description. These results increase the number of Oxyethira species in Brazil from 37 to 39.


Sujet(s)
Neoptera/classification , Animaux , Brésil , Système génital de l'homme/anatomie et histologie , Mâle , Neoptera/anatomie et histologie , Neoptera/physiologie
2.
Zootaxa ; 4950(3): zootaxa.4950.3.9, 2021 Mar 31.
Article de Anglais | MEDLINE | ID: mdl-33903432

RÉSUMÉ

A new species of Timnewia from the Brazilian state of Amazonas, is here described, illustrated and named as: Timnewia amazonense n. sp. This new species differs from T. greeni and T. jeaneae in details of the hypandrium and phallosome. New observations on variation in the forewing venation of T. jeaneae are also presented.


Sujet(s)
Neoptera , Répartition des animaux , Animaux , Insectes , Neoptera/classification , Neoptera/physiologie , Ailes d'animaux
3.
PLoS One ; 15(1): e0220275, 2020.
Article de Anglais | MEDLINE | ID: mdl-31929552

RÉSUMÉ

Many freshwater ecosystems worldwide, and particularly Mediterranean ones, show increasing levels of salinity. These changes in water conditions could affect abundance and distribution of inhabiting species as well as the provision of ecosystem services. In this study we conduct laboratory experiments using the macroinvertebrate Smicridea annulicornis as a model organism. Our factorial experiments were designed to evaluate the effects of geographical origin of organisms and salinity levels on survival and behavioral responses of caddisflies. The experimental organisms were captured from rivers belonging to three hydrological basins along a 450 Km latitudinal gradient in the Mediterranean region of Chile. Animals were exposed to three conductivity levels, from 180 to 1400 µS/cm, close to the historical averages of the source rivers. We measured the behavioral responses to experimental stimuli and the survival time. Our results showed that geographical origin shaped the behavioral and survival responses to salinity. In particular, survival and activity decreased more strongly with increasing salinity in organisms coming from more dilute waters. This suggests local adaptation to be determinant for salinity responses in this benthic invertebrate species. In the current scenario of fast temporal and spatial changes in water levels and salt concentration, the conservation of geographic intra-specific variation of aquatic species is crucial for lowering the risk of salinity-driven biodiversity loss.


Sujet(s)
Adaptation physiologique , Longévité/effets des médicaments et des substances chimiques , Neoptera/effets des médicaments et des substances chimiques , Chlorure de sodium/pharmacologie , Animaux , Biodiversité , Chili , Écosystème , Eau douce , Géographie , Neoptera/physiologie , Salinité
4.
An Acad Bras Cienc ; 91(3): e20180692, 2019.
Article de Anglais | MEDLINE | ID: mdl-31618411

RÉSUMÉ

The assessment of biotic-habitat relationships provides key information to predict biotic responses to perturbations and important tools for river management and monitoring. This study aimed to assess the spatial distribution of Ephemeroptera and Trichoptera in mountain streams of central Argentina. We evaluated the effect of seasonality and identified the variables conditioning the abundance of the assemblages and the habitat with the highest taxonomic richness. Sampling was carried out in four streams (Carcarañá River basin) during high and low water periods. Three lotic habitats were sampled: riffles, coarse substrate runs, and fine substrate runs; and physicochemical and habitat variables were measured. We found differences in assemblage composition, among the 25 genera of Ephemeroptera and Trichoptera, at the habitat level. The most important variables affecting distribution patterns were substrate and flow type, but macroalgae and organic matter (twigs, leaves, and detritus) were also important predictors. Riffles maintained the highest richness but when considering only the Ephemeroptera taxa, fine substrate runs emerged also as an important habitat for these taxa. Our study provided valuable ecological information related to habitat preference of taxa with a key role in stream functioning and of great usefulness for the monitoring of lotic systems.


Sujet(s)
Écosystème , Surveillance de l'environnement/méthodes , Ephemeroptera/physiologie , Neoptera/physiologie , Rivières , Animaux , Argentine , Ephemeroptera/classification , Neoptera/classification , Analyse en composantes principales , Spécificité d'espèce
5.
Protoplasma ; 256(3): 839-856, 2019 May.
Article de Anglais | MEDLINE | ID: mdl-30643985

RÉSUMÉ

The effects of biopesticides on insects can be demonstrated by morphological and ultrastructural tools in ecotoxicological analysis. Azadirachtin-based products are widely used as biopesticides, affecting numerous insect populations. Through morphological biomarkers, this study aimed to characterize the fat bodies of both the southern armyworm Spodoptera eridania and the predator Ceraeochrysa claveri after chronic exposure to azadirachtin. Larvae of S. eridania and C. claveri were fed with fresh purple lettuce leaves (Lactuca sativa) and egg clusters of Diatraea saccharalis treated with azadirachtin solution of 6 mg active ingredient (a.i.)/L and 18 mg a.i./L for 7 days, respectively. The biological data showed a significant reduction in survival and body mass in S. eridania and cytotoxic effects in the parietal and perivisceral fat bodies in both species. Ultrastructural cell damage was observed in the trophocytes of both species such as dilated cisternae of the rough endoplasmic reticulum and swollen mitochondria. Trophocytes of S. eridania and C. claveri of the parietal and perivisceral layers responded to those injuries by different cytoprotective and detoxification means such as an increase in the amount of cytoplasmic granules containing calcium, expression of heat shock protein (HSP)70/HSP90, and development of the smooth endoplasmic reticulum. Despite all the different means of cytoprotection and detoxification, they were not sufficient to recover from all the cellular damages. Azadirachtin exhibited an excellent performance for the control of S. eridania and a moderate selectivity for the predator C. claveri, which presents better biological and cytoprotective responses to chronic exposure to azadirachtin.


Sujet(s)
Corps gras/physiologie , Limonines/pharmacologie , Neoptera/physiologie , Lutte biologique contre les nuisibles , Comportement prédateur , Spodoptera/physiologie , Animaux , Dosage biologique , Corps gras/cytologie , Corps gras/effets des médicaments et des substances chimiques , Corps gras/ultrastructure , Larve/effets des médicaments et des substances chimiques , Larve/ultrastructure , Neoptera/effets des médicaments et des substances chimiques , Neoptera/ultrastructure , Spodoptera/effets des médicaments et des substances chimiques , Spodoptera/ultrastructure
6.
Neotrop Entomol ; 48(1): 57-70, 2019 Feb.
Article de Anglais | MEDLINE | ID: mdl-30066276

RÉSUMÉ

The continuous pursuit of welfare and economic development through the exploitation of natural resources by human societies consequently resulted in the ongoing process of climate change. Changes in the distribution of species towards the planet's poles and mountain tops are some of the expected to biological consequences of this process. Here, we assessed the potential effects of future climate change on four cool-adapted Gripopterygidae (Insecta: Plecoptera) species [Gripopteryx garbei Navás 1936, G. cancellata (Pictet 1841), Tupiperla gracilis (Burmeister 1839), and T. tessellata (Brauer 1866)] from Southeastern Brazilian Atlantic forest. As species adapted to cold conditions, in the future scenarios of climate change, we expected these organisms to shrink/change their distributions ranges towards areas with suitable climatic conditions in Southern Brazilian regions, when compared with their predicted distributions in present climatic conditions. We used seven principal components derived from 19 environmental variables from Worldclim database for the present scenario and also seven principal components obtained from 17 different Atmosphere-Ocean Global Circulation Models (AOGCMs), considering the most severe emission scenario for green-house gases to predict the species' distributions. Depending on the climatic scenario considered, there were polewards distribution range changes of the species. Additionally, we also observed an important decrease in the amount of protected modeled range for the species in the future scenarios. Considering that this Brazilian region may become hotter in the future and have its precipitation regime changed, as observed in the severe 2013-2014 drought, we believe these species adapted to high altitudes will be severely threatened in the future.


Sujet(s)
Adaptation physiologique , Changement climatique , Neoptera/physiologie , Animaux , Biodiversité , Brésil , Basse température , Conservation des ressources naturelles , Forêts , Modèles biologiques
7.
J Therm Biol ; 74: 133-139, 2018 May.
Article de Anglais | MEDLINE | ID: mdl-29801618

RÉSUMÉ

Two strategies have been described for cold tolerance in arthropods: (1) freeze-tolerant organisms, which can survive the formation of ice crystals and (2) freeze-avoidant organisms, which prevent the ice crystal formation by super cooling their internal fluids. We studied two arthropods from the Andean Range in central Chile (2400 m a.s.l.), the stick insect Agathemera crassa commonly named as "Chinchemolle", and the tarantula spider Euathlus condorito commonly named as "Araña pollito", in order to evaluate how they respond to low temperatures at the physiological and molecular levels. We sampled the soil temperature during one year to track the temperature changes that these organisms must overcome. We found minimum temperatures around -6 °C in autumn, while the temperature were stable at 0 °C in winter due to the snow. The average field-cooling rate was 0.01 ±â€¯0.006 °C min-1. For both arthropods we determined the super cooling point (SCP) at a cooling rate of 1 °C min-1 and its subsequent survival, finding that A. crassa is a freezing tolerant organism with a SCP of -3.8 ±â€¯1.8 °C and 100% survival, while E. condorito is a freezing avoidant organism with a SCP of -3.0 ±â€¯1.3 °C and 0% survival. The SCP and survival were not affected by the season in which individuals were collected, the SCP was significantly affected by the cooling rate of the experiment. Both species had low molecular weight cryoprotective in their hemolymph that could explain their cold-tolerance behavior. Glucose, glycerol, and trehalose were found in A. crassa's hemolymph, only glucose and glycerol were found in E. condorito's. We analyzed the hemolymph proteins and found no seasonal differences in composition for either species and also we detected protein antifreeze activity in the hemolymph from both arthropods.


Sujet(s)
Neoptera/physiologie , Araignées/physiologie , Acclimatation , Animaux , Protéines antigel/métabolisme , Chili , Basse température , Hémolymphe/métabolisme , Protéines d'insecte/métabolisme , Sol
8.
Neotrop Entomol ; 47(1): 118-130, 2018 Feb.
Article de Anglais | MEDLINE | ID: mdl-28664528

RÉSUMÉ

Chrysoperla externa (Hagen) larvae prey on pest insects and mites in agroecosystems, and adults mainly feed on pollen, nectar, and honeydew. Therefore, preserving this lacewing in crop systems depends on having plants that provide these resources. The objectives of this research were to identify pollen grains ingested by Ch. externa adults collected in a diversified organic agroecosystem and to evaluate whether there is a difference in the amount of ingested pollen grains between males and females. The adults of Ch. externa were collected in four different crops during 13 months in Seropédica, state of Rio de Janeiro, Brazil, using a collecting net. The adults were killed and underwent acetolysis, in order to recover the pollen in the gut. A total of 37,441 pollen grains from 19 Angiospermae families were found, besides 16 Pteridophyte spores. Among the recognized pollen grains, those of Poaceae were the majority, both in frequency of occurrence (87.5%) and in quantity (33496), and were found and recovered in every month of collection. Females and males ingested, respectively, 71.9 and 28.1% of the total number of Angiospermae pollen grains consumed by both sexes. The highest number of Poaceae pollens was obtained from the females (72.1% of the total number of Poaceae pollen, recovered from females + males). Taken as a whole, this study showed that adults of Ch. externa find possibilities to maintain throughout the year, in different crops, but the main source of pollen to males and females was Poaceae plants.


Sujet(s)
Régime alimentaire/médecine vétérinaire , Neoptera/physiologie , Pollen , Animaux , Brésil , Produits agricoles , Femelle , Larve , Mâle
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