10 research outputs found
INFLUÊNCIA DE VARIÁVEIS AMBIENTAIS NAS FUNÇÕES ECOLÓGICAS DE ESCARABEÍNEOS EM SISTEMAS DE USO DO SOLO NO CAPARAÓ CAPIXABA
As funções ecológicas realizadas pelos besouros escarabeíneos, ou “rola-bostas”, foram estudadas nos três principais sistemas de uso do solo da região do Caparaó Capixaba: lavouras de café, pastagens e fragmentos florestais. Nos ambientes de florestas foi observada uma maior quantidade média de fezes enterradas em relação aos cafezais, já nas pastagens não houve diferenças significativas com os demais sistemas de uso do solo. As correlações entre as variáveis ambientais e as funções ecológicas estudadas puderam nos mostrar a influência da composição do solo e do tipo de vegetação sobre o enterrio de fezes e revolvimento do solo realizados pelos besouros. A complexidade da vegetação, medida através da dimensão fractal da vegetação indicou uma maior complexidade estrutural na floresta em relação à pastagem. O trabalho auxiliou no entendimento do funcionamento dos principais sistemas de uso do solo da região do Caparaó Capixaba
Indutores de resistência à mosca-branca Bemisia tabaci Biótipo B (GENN., 1889) (Hemiptera: Aleyrodidae) em soja
Stridulations Reveal Cryptic Speciation in Neotropical Sympatric Ants
The taxonomic challenge posed by cryptic species underlines the importance of using multiple criteria in species delimitation. In the current paper we tested the use of acoustic analysis as a tool to assess the real diversity in a cryptic species complex of Neotropical ants. In order to understand the potential of acoustics and to improve consistency in the conclusions by comparing different approaches, phylogenetic relationships of all the morphs considered were assessed by the analysis of a fragment of the mitochondrial DNA cytochrome b. We observed that each of the cryptic morph studied presents a morphologically distinct stridulatory organ and that all sympatric morphs produce distinctive stridulations. This is the first evidence of such a degree of specialization in the acoustic organ and signals in ants, which suggests that stridulations may be among the cues used by these ants during inter-specific interactions. Mitochondrial DNA variation corroborated the acoustic differences observed, confirming acoustics as a helpful tool to determine cryptic species in this group of ants, and possibly in stridulating ants in general. Congruent morphological, acoustic and genetic results constitute sufficient evidence to propose each morph studied here as a valid new species, suggesting that P. apicalis is a complex of at least 6 to 9 species, even if they present different levels of divergence. Finally, our results highlight that ant stridulations may be much more informative than hitherto thought, as much for ant communication as for integrative taxonomists
Diversité Cryptique, Bioacoustique et Interactions Intra et Interspécifiques dans le Complexe d Espèces Primitives Néotropicales Pachycondyla apicalis (Hymenoptera : Formicidae : Ponerinae)
La région Néotropicale abrite une extraordinaire diversité biologique, dont une grande partie encore non identifiée. En outre, parmi les espèces déjà inventoriées, plusieurs groupes sont soumis à des classifications imparfaites. Ceci est particulièrement dû à l'existence d'espèces cryptiques formant des complexes d'espèces qui empêchent l évaluation correcte de la biodiversité. Les fourmis primitives du complexe Pachycondyla apicalis sont un bon exemple de ce fait et leur taxonomie n est pas consensuelle. Etant donné que l'identification exacte des espèces est essentielle à la fois à la recherche dans tous les domaines de la biologie et à la conservation de la biodiversité, l un des objectifs premiers de ce travail a été la détermination de la diversité cryptique au sein de ce complexe d espèces. L étude des organes producteurs de son et des signaux stridulatoires ont démontré que ces espèces morphologiquement semblables possèdent des différences spécifiques nettes dans leurs systèmes de communication acoustique respectifs. Les résultats acoustiques ont été corroborés par des analyses moléculaires, confirmant ainsi que la bioacoustique est un outil potentiel pour la détermination des espèces cryptiques dans ce groupe de fourmis. Ce résultat est la première indication d'un tel degré de spécialisation dans les signaux stridulatoires des fourmis, ce qui suggère que les stridulations peuvent présenter un rôle encore plus important dans la vie de ces espèces. Bien qu indiscernables pour l'œil humain, ces espèces cryptiques sont évidemment dissemblables les unes des autres. De ce fait, nous avons pu au travers d études bioacoustiques, génétiques, chimiques, écologiques et comportementales caractériser des éléments de la biologie de ces espèces pouvant être considérés comme indicateurs de l espèce, et ceci également dans le but de mieux comprendre les interactions intra- et interspécifiques dans ce groupe d espèces phylogénétiquement proches.The Neotropical region is home to an extraordinary biological diversity, much of which still unidentified. In addition, among the species already described, several groups are subject to imperfect classifications. This is particularly due to the existence of cryptic species which form species complex that prevent the correct assessment of biodiversity. The primitive ants from the Neotropical Pachycondyla apicalis complex are a good example of this fact and their taxonomy is still unsolved. Since the correct identification of species is essential both for research in all fields of biology and the conservation of biodiversity, one of the primary objectives of this work was the determination of cryptic diversity within this species complex. The study of the stridulatory organs and signals showed that these morphologically similar species have clear specific differences in their respective acoustic communication systems. The acoustic results were corroborated by molecular analysis, confirming bioacoustics as a potential tool for the determination of cryptic species in this group of ants. This is the first indication of such a degree of specialization in the stridulatory signals of ants, suggesting that stridulations may have an even more important role in the lives of these species. Even if indistinguishable to the human eye, these cryptic species are obviously dissimilar from each other. Thus we were able through acoustic, genetic, chemical, ecological and behavioural studies to characterize biological elements of these species that can be considered as indicators of the species, and this also in order to better understand intra and interspecific interactions in this group of phylogenetically related species.PARIS13-BU Sciences (930792102) / SudocSudocFranceF
Indutores de resistência à mosca-branca Bemisia tabaci Biótipo B (GENN., 1889) (Hemiptera: Aleyrodidae) em soja Resistance inducers to the whitefly Bemisia tabaci Biotype B (GENN., 1889) (Hemiptera: Aleyrodidae) in soybeans
Objetivou-se, neste trabalho, avaliar o efeito da aplicação de indutores na resistência de duas cultivares de soja à mosca-branca Bemisia tabaci biótipo B. O experimento foi conduzido no Departamento de Entomologia - UFLA. As sementes de soja, cultivar IAC-19 e MONSOY-8001, foram previamente tratadas com o fungicida captan. Foram testados os seguintes tratamentos: T1- irrigação no solo, ao redor das plantas de cada vaso, de 250 mL de solução de ácido silícico a 1%; T2- pulverização das plantas, até o ponto de escorrimento, com solução a 0,3% de acibenzolar-s-methyl; T3- pulverização das plantas, até o ponto de escorrimento, com calda a 0,24% de pyraclostrobin+epoxiconazole e T4- testemunha. As plantas foram infestadas com 100 adultos da mosca-branca por vaso que liberados oito dias após a aplicação dos tratamentos. Avaliaram-se o número de ovos na face abaxial de cada folha, que foi marcada para posterior avaliação de ninfas; teores de taninos e de lignina; peso seco das raízes e da parte aérea. Não houve diferença para número de ovos e ninfas entre as cultivares de soja, porém, a viabilidade média de B. tabaci foi menor a cultivar IAC-19. O cultivar de soja IAC-19 demonstrou moderada resistência ao biótipo B de B. tabaci. A aplicação de silício ou acibenzolar-s-methyl induz um aumento no teor de lignina na cultivar de soja IAC-19.The objective of this paper was to evaluate the effect of the application of inducers on the resistance of two soybean cultivars to the whitefly B. tabaci Biotype B. The experiment was carried out at the Entomology Department - UFLA. The soybean seeds of cultivars IAC-19 and MONSOY-8001 were previously treated with Captan fungicide. The following treatments were tested: T1- irrigating the soil around the plants of each pot with 250 mL of solution of 1% silicic acid; T2- spraying of the plants, to the 'point of dripping', with a solution of 0.3% acibenzolar-s-methyl; T3- spraying of the plants, to the 'point of dripping', with a solution of 0.24% pyraclostrobin+epoxiconazole, and T4- control. The plants were infested with 100 adult whiteflies that were released eight days after applying the treatments. The number of eggs on the abaxial face of each leaf, which was marked for further evaluation of nymphs, tannin and lignin contents, dry weight of the aerial parts and roots, was evaluated. There was no difference for the number of eggs and nymphs among the soybean cultivars. Nevertheless, the average survival rate of B. tabaci was lower on cultivar IAC-19. The application of silicon or acibenzolar-s-methyl induces an increase in lignin content in the soybean cultivar IAC-19
Behavioural Contexts of Sound Production inPachycondyla Ants (Formicidae: Ponerinae)
International audienc
Temporary prey storage along swarm columns of army ants: an adaptive strategy for successful raiding?
While pillaging the brood of other ant colonies, Eciton army ants accumulate prey in piles, or caches, along their foraging trails. Widely documented, these structures have historically been considered as by-products of heavy traffic or aborted relocations of the ants' temporary nest, or bivouac. However, we recently observed that caches of the hook-jawed army ant, Eciton hamatum, appeared independently from heavy traffic or bivouac relocations. In addition, the flow of prey through caches varied based on the quantity of prey items workers transported. As this suggested a potential adaptive function, we developed agent-based simulations to compare raids of caching and non-caching virtual army ants. We found that caches increased the amount of prey that relatively low numbers of raiders were able to retrieve. However, this advantage became less conspicuous-and generally disappeared-as the number of raiders increased. Based on these results, we hypothesize that caches maximize the amount of prey that limited amounts of raiders can retrieve, especially as prey colonies coordinately evacuate their brood. In principle, caches also allow workers to safely collect multiple prey items and efficiently transport them to the bivouac. Further field observations are needed to test this and other hypotheses emerging from our study.Nanyang Technological UniversityA CNPq Productivity grant (PQ-2017 grant no. 311790/2017-8) to N.C.; a CAPES PROEX Psicologia Experimental 2016/1964 to N.C., H.P.d.L., R.S.F.-C., R.L.C.d.L. and PROCAD Amazônia; a Presidential Postdoctoral Fellowship (M408080000) from Nanyang Technological University to S.T. CNPq provided H.P.d.L.’s PhD scholarship
Permanent genetic resources added to Molecular Ecology Resources Database 1 October 2010-30 November 2010
This article documents the addition of 277 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Ascochyta rabiei, Cambarellus chapalanus, Chionodraco hamatus, Coptis omeiensis, Cynoscion nebulosus, Daphnia magna, Gerbillus nigeriae, Isurus oxyrinchus, Lates calcarifer, Metacarcinus magister, Oplegnathus fasciatus, Pachycondyla verenae, Phaethon lepturus, Pimelodus grosskopfii, Rotylenchulus reniformis, Scomberomorus niphonius, Sepia esculenta, Terapon jarbua, Teratosphaeria cryptica and Thunnus obesus. These loci were cross-tested on the following species: Austropotamobius italicus, Cambarellus montezumae, Cambarellus puer, Cambarellus shufeldtii, Cambarellus texanus, Chionodraco myersi, Chionodraco rastrospinosus, Coptis chinensis, Coptis chinensis var. brevisepala, Coptis deltoidea, Coptis teeta, Orconectes virilis, Pacifastacus leniusculus, Pimelodus bochii, Procambarus clarkii, Pseudopimelodus bufonius, Rhamdia quelen, Sepia andreana, Sepiella maindroni, Thunnus alalunga, Thunnus albacares, Thunnus maccoyii, Thunnus orientalis, Thunnus thynnus and Thunnus tonggol