23736 research outputs found
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An oviposition trap to collect immatures of coprophagous moth flies (Diptera: Psychodidae)
Full text linkLarvae of Psychodidae develop in a variety of breeding sites, including vertebrate feces. As searching for the larvae can be an extremely difficult task, immatures of many species are little known, with descriptions of coprophagous moth flies all from outside the Neotropics. In an attempt to mitigate this challenge, we tested an oviposition trap using cattle dung as attractant, measured the efficiency and specificity of the traps and the most efficient period of exposition in the field. With 60 traps installed in one fragment of ombrophilous forest, 344 immatures were collected, distributed in four species of Psychoda and one of Feuerborniella. Psychodidae accounted for 75% of the collected Diptera. The high specificity of the trap to Psychodidae contrasts with other studies on coprophagous fauna where they appear in low abundance. Based on the metrics in this study, the most efficient period of trapping exposition was between five to eight days, but the difference was not significant probably due to the high number of zero observations among the traps. Many questions pertaining to coprophagous moth flies remain unanswered. Further research is needed to improve trapping efficiency, elucidate the effects of attractants and determine how environmental factors influence the attractiveness of bait
Seven new species of spider-attacking hymenoepimecis viereck (Hymenoptera, ichneumonidae, pimplinae) from Ecuador, French Guiana, and Peru, with an identification key to the world species
No full textSeven new species of Hymenoepimecis Viereck are described from Peruvian Andes and Amazonia, French Guiana and Ecuador: H. andina Pádua & Sääksjärvi, sp. nov., H. castilloi Pádua & Sääksjärvi, sp. nov., H. dolichocarinata Pádua & Sääksjärvi, sp. nov., H. ecuatoriana Pádua & Sääksjärvi, sp. nov., H. longilobus Pádua & Sääksjärvi, sp. nov., H. pucallpina Pádua & Sääksjärvi, sp. nov., and H. rafaelmartinezi Pádua & Sääksjärvi, sp. nov. In addition, the male of the Hymenoepimecis kleini Pádua & Sobczak, 2015 is described, new faunistic records for the genus provided, as well as an illustrated identification key to all known species of the genus. © 2020, Pensoft Publishers. All rights reserved
Defining a termite sampling protocol for ecological studies: An effective method to increase statistical power
Full text linkProtocols for sampling soil fauna are usually designed to increase the number of species found when one or a few plots are heavily sampled. However, no previous study has evaluated how the number of plots sampled affect the power of statistical tests associating community composition and the environment. We test the effect of the number of transects (plots) and the sampling effort in each transect on the representation of trophic groups and on the association of termite species composition with environmental variables. Data were collected in 30 250m-long transects located in central Amazonia. Each transect was subdivided into 10 non-contiguous sections of 5 m × 2 m each (separation of 22 m between sections). We rarefied the data to determine arrangement of transects and sections that 1) best characterizes the distribution of species in trophic groups and 2) maximizes the chances to detect true associations between termite species composition and environmental predictor variables. When more than six transects (plots) were sampled with at least five non-contiguous sections each, the distribution of trophic groups was similar to the known distribution for the area. However, the detection of the association between termite species composition and environmental variables was more easily detected by increasing the number of transects sampled (plots) than the sampling effort per transect. Our results suggest that spreading sampling effort into at least 15 transects (plots) improves the ability to detect trophic groups and the performance of regression tests associating the composition of species with the environment. © 2019 Elsevier Masson SA
Small forest losses degrade stream macroinvertebrate assemblages in the eastern Brazilian Amazon
Full text linkGenerally, habitat loss and fragmentation negatively affect biota, often in nonlinear ways. Such nonlinear responses suggest the existence of critical limits for habitat loss beyond which taxa experience substantial changes. Therefore, we identified change points for aquatic macroinvertebrate assemblages at both local-riparian and catchment extents in response to a forest-loss gradient in agriculture-altered landscapes of 51 small (1st to 3rd Strahler order) eastern Amazon streams. We used Threshold Indicator Taxa Analysis (TITAN) to identify change points for individual taxa and segmented regression analysis for assemblage richness. Considering the patterns of the cumulative frequency distributions of sum(Z−) maxima across bootstrap replications, peak changes in macroinvertebrate assemblages were at ∼9% (5–95 percentiles = 1–15%) of forest-loss at the catchment extent, and at ∼1.4% (5–95 percentiles = 0–35%) of forest-loss at the local-riparian extent. Although the assemblage change point at the site extent was less than that detected at the catchment extent, the markedly lower percentile range indicates that biotic assemblages are more clearly responsive to forest-loss at the catchment/network-riparian extents than the site extent. For catchment and site extents, segmented regression analysis determined a change point for assemblage richness at 57% and 79% of forest-loss, respectively. This indicates the low capacity of total richness to separate early and synchronous decreases of sensitive taxa from gradual increases of tolerant taxa. Our results also show that it is not enough to focus management and conservation actions on riparian zones, but that conservation strategies should be expanded to entire catchments as well. The sharp decline of sensitive taxa in response to removal of a small portion of forest cover, even at catchment extents, indicates that the Brazilian Forest Code is insufficient for protecting stream macroinvertebrates. Consequently, we recommend strategies to reverse the potential collapse of aquatic biodiversity, particularly through avoiding deforestation and forest degradation, encouraging socio-economic incentives for restoring degraded areas, creating protected areas, and maintaining the current protected areas. We argue that reducing habitat loss should be a top priority for conservation planners in tropical forests because the sensitivity of aquatic biodiversity to removal of riparian forest-cover in Amazon rainforests is higher than previously thought. Therefore, the Forest Code regulatory framework needs complementary regulation that may be achived by more restrictive State and biome policies. © 2019 Elsevier Lt
New Neotropical species of Lachesilla Westwood, in species group forcepeta (Psocodea: ‘Psocoptera’: Lachesillidae)
No full textEight species of Lachesilla, in species group forcepeta, are described and illustrated: three species from Costa Rica (Lachesilla herediana n. sp., Lachesilla raravis n. sp., and Lachesilla ticana n. sp.), one species from Costa Rica and Panama (Lachesilla odontiforceps n. sp.), one species each from Brazil (Lachesilla oriximinaensis n. sp.), Mexico (Lachesilla concaensis n. sp.) and Panama (Lachesilla albrookensis n. sp.), and one species from Guatemala, Mexico and Panama (Lachesilla tenuidenticulata n. sp.). The location of the types is indicated in each description. Copyright © 2020 Magnolia Pres
A cladistic approach for generic delimitation of paracloeodes day, rivudiva lugo-ortiz & McCafferty, and varipes lugo-ortiz & McCafferty (ephemeroptera: Baetidae).
No full textThe taxonomic knowledge of Baetidae has been greatly improved in the last decades in South America. Despite the advances, there are problems that need to be addressed. One of these problems is doubt concerning the systematics of species assigned to the genera Paracloeodes Day, Rivudiva Lugo-Ortiz & McCafferty, and Varipes Lugo-Ortiz & McCafferty, and the evolution of long setae on femora. In the present paper, the monophyly of these three genera is tested using a cladistic approach. The matrix included 53 species and 151 morphological characters: 127 for nymphs and 24 for adults. The dataset was analyzed under equal and implied weights with nine values of k. Group support was estimated with relative Bremer and frequency differences. The results corroborate (i) the paraphyly of Paracloeodes and Varipes, which become monophyletic without P. caldensis + V. singuil, proposed as a new genus Rhopyscelis gen. n., (ii) the long setae on femora as an independent acquisition between Rhopyscelis gen. n. + Varipes and Rivudiva, (iii) the transversal rows of setae on femora as an independent acquisition between Rhopyscelis gen. n. + Varipes and Rivudiva, (iv) the spine on subgenital plate as an independent acquisition between Paracloeodes, Rivudiva and Gen. A. © Koninklijke Brill NV, Leiden, 2018
A molecular assessment of species diversity in Tympanopleura and Ageneiosus catfishes (Auchenipteridae: Siluriformes)
No full textIn order to test the congruence of genetic data to the morphologically defined Neotropical catfish genera Tympanopleura and Ageneiosus and explore species diversity, we generated 17 DNA barcodes from five of six species of Tympanopleura and 12 of 13 species of Ageneiosus. To discriminate limits between species, an automatic barcode gap discovery (ABGD), a generalised mixed yule-coalescent model (GYMC) and fixed distance thresholds Kimura two-parameter (K2P; 3%) were used to discriminate putative species limits from the DNA barcodes. The ABGD, GMYC and K2P methods agreed by each generating 13 clusters: six in Tympanopleura (five nominal plus one undescribed species) and seven in Ageneiosus. These clusters corresponded broadly to the described species, except in the case of the Ageneiosus ucayalensis group (A. akamai, A. dentatus, A. intrusus, A. ucayalensis, A. uranophthalmus and A. vittatus). Haplotype sharing and low divergences may have prevented molecular methods from distinguishing these species. We hypothesise that this is the result of a recent radiation of a sympatric species group distributed throughout the Amazon Basin. One putative new species of Tympanopleura was also supported by the molecular data. These results taken together highlight the utility of molecular methods such as DNA barcoding in understanding patterns of diversification across large geographic areas and in recognising overlooked diversity. © 2019 The Fisheries Society of the British Isle
The evolution of Zoraptera
Full text linkZoraptera is one of the most enigmatic and least understood orders in insects. Based on a wide taxon sampling from all continents where the group is known, we applied a phylogenetic approach using multiple DNA sequences to elucidate species-level relationships. The resulting phylogeny shows that Zoraptera is divided into three major clades, and that two comprise species distributed on different continents. The monophyly of these clades is at least partly supported by shared derived morphological features. The divergence age estimation and ancestral distribution area reconstruction suggest an ancient origin and early radiation initiated in the Permian. Plate tectonics theory suggests that the present distribution of Zoraptera was mainly established by vicariance, rather than dispersal. The three major clades probably originated on the Pangaea supercontinent, or alternatively on the linked Gondwana and Laurasia supercontinents. Their ancient origin explains previously found conspicuous interspecific variation of the genital apparatus, sperm structure and mating behaviour, in striking contrast to a highly conserved general body morphology. We compiled data of available reproductive features and reconstructed the character evolution. Our analyses revealed repeated acquisitions and/or losses of a hyperelongated intromittent organ, mating hooks and tergal protuberances. © 2019 The Authors. Systematic Entomology published by John Wiley & Sons Ltd on behalf of The Royal Entomological Society
Activity pattern, budget and diurnal rhythmicity of the brown-throated three-toed sloth (Bradypus variegatus) in northeastern Brazil
No full textPrevious studies exploring the rhythmic activity of sloths of the Bradypus genus in undisturbed forests revealed cathemeral patterns of activity. In the current study we wished to examine sloth behavior in a highly disturbed secondary forest habitat. We evaluated activity pattern, time budget and rhythmic activities of brown-throated three-toed sloths (B. variegatus) living in the border of a highly disturbed forest fragment in northeastern Brazil. Three adults (2 females and 1 male) and 2 infants were studied over 29 days. Observational data were collected in 15 min increments over the 24-h day in the following categories: resting, moving, travelling, eating and grooming. Time series data were subjected to X2 periodogram, Fourier (Fast Fourier Transformation, FFT), cosinor and CircWave circadian rhythm analysis, and revealed significant 24-h rhythms in all behaviors in most circumstances. Unlike sloths located in an undisturbed forest, this population exhibited primarily diurnal activity patterns of behavior, with the center of gravity for each behavior occurring in the middle of the day. Furthermore, several behaviors were expressed in a bimodal pattern, with a morning and a late afternoon peak of activity. These data suggest that with decreased predator presence and with a more ubiquitous food source, sloths adjust their temporal niche to daytime. © 2020, Deutsche Gesellschaft für Säugetierkunde
