Navegando por Autor "Delabie, Jacques Hubert Charles"

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A riqueza e composição de formigas como indicadores dos efeitos do manejo florestal de baixo impacto em floresta tropical no estado do Acre
(Revista Árvore, 2012-12-20) Miranda, Patricia Nakayama; Morato, Elder Ferreira; Oliveira, Marco Antonio; Delabie, Jacques Hubert Charles
A sustentabilidade da extração madeireira seletiva depende de avaliações de impacto e monitoramento dos fatores abióticos, vegetação e fauna. Os objetivos deste trabalho foram estimar e comparar a riqueza e composição de formigas em área de manejo florestal sustentável de baixo impacto, no Projeto de Assentamento Chico Mendes, no Acre. As coletas foram realizadas com armadilhas pitfall e extrator de Winkler, em 30 parcelas de 10 x 10 m. As parcelas foram igualmente distribuídas em três tratamentos: (1) manejo - base de árvores exploradas em 2007; (2) queda natural - base de árvores caídas naturalmente em área não manejada; e (3) controle - parcela sem queda de árvore na mesma área não manejada. Para a caracterização da vegetação, foram tomadas medidas das variáveis: densidade arbórea e arbustiva, área basal arbórea e de árvores caídas, espessura de serapilheira e cobertura de dossel. A densidade arbórea foi significantemente maior no tratamento controle que no manejo. Diferenças significativas foram encontradas em cobertura de dossel entre os tratamentos controle e manejo e controle e queda natural. Foram coletadas 88 espécies de formigas, distribuídas em sete subfamílias. Não houve diferença na riqueza de espécies entre os tratamentos. Embora menor similaridade tenha sido encontrada entre os tratamentos manejo e controle, não foram observadas grandes diferenças na composição entre eles. Esses resultados indicaram que, nessa área, a atividade de extração madeireira de baixo impacto não afetou a assembleia de formigas, portanto, funcionalmente, essa forma de manejo não acarretou alterações no ecossistema em relação aos serviços associados às formigas.
Banding patterns of three leafcutter ant species of the genus Atta (Formicidae: Myrmicinae) and chromosomal inferences
(Florida Entomologist, 2014-12) Barros, Luísa Antônia Campos; Teixeira, Gisele Amaro; Aguiar, Hilton Jeferson Alves Cardoso de; Mariano, Cléa Dos Santos Ferreira; Delabie, Jacques Hubert Charles; Pompolo, Silvia das Graças
Among Neotropical ants, the genera Acromyrmex and Atta are of great importance because they include the major agricultural pest species. Regarding the genus Atta, considered one of the most derived of the tribe Attini, cytogenetic data exists for 5 taxa that present 2n = 22 chromosomes; however, information regarding banding patterns is only available for Atta colombica. Cytogenetics has contributed to several aspects related to the family Formicidae, in particular to the understanding of its evolution. Therefore, the aim of this study was to increase the cytogenetic data on Atta sexdens rubropilosa, Atta laevigata and Atta bisphaerica belonging to populations in the state of Minas Gerais, Brazil. The 3 species were characterized as having 2n = 22 chromosomes with a karyotypic formula of 2n = 18m 2sm 2st. Using the C-banding technique, small heterochromatic markings were observed in the centromeres of most of the chromosomes. The presence of GC-rich blocks in the interstitial region on the long arm of the fourth pair of metacentric chromosomes was indicated by CMA3 fluorochrome. The data from this study enabled a comparison with Acromyrmex striatus, a phylogenetically close species possessing the same chromosome number as the Atta species studied in this work, although clear differences were evident in the morphologies of 2 chromosome pairs and in the distribution and composition of heterochromatin. These results show the constancy of the chromosome number, morphology and banding pattern for the species studied, highlighting the importance of measuring the chromosomes to enable accurate comparison and using banding techniques to compare species of genera with a conserved chromosome number.
Caracterização de ninhos e tamanho de colônia de Acromyrmex rugosus (F. Smith) (Hymenoptera, Formicidae, Attini) em restingas de Ilhéus, BA, Brasil
(Revista Brasileira de Entomologia, 2006-03) Soares, Ilka Maria Fernandes; Lucia, Terezinha Maria Castro Della; Santos, Adriana Anadir dos; Nascimento, Ivan Cardoso; Delabie, Jacques Hubert Charles
Oito ninhos de Acromyrmex rugosus foram escavados para estudar sua estrutura e estimar sua população. Esses ninhos eram sempre encontrados escondidos por plantas; apresentaram pequena quantidade de solo e tinham 1 ou 2 entradas; uma delas tinham a forma de um "U" invertido. Internamente, o número de câmaras foi variável e o volume de fungo foi pequeno(X=196 ml). O total da população do ninho foi aproximadamente, 895 indivíduos.
Cytogenetic data on six leafcutter ants of the genus Acromyrmex Mayr, 1865 (Hymenoptera, Formicidae, Myrmicinae): insights into chromosome evolution and taxonomic implications
(Comparative Cytogenetics, 2016-05-11) Barros, Luísa Antônia Campos; Aguiar, Hilton Jeferson Alves Cardoso de; Mariano, Cléa dos Santos Ferreira; Andrade-Souza, Vanderly; Costa, Marco Antonio; Delabie, Jacques Hubert Charles; Pompolo, Silvia das Graças
Cytogenetic data for the genus Acromyrmex Mayr, 1865 are available, to date, for a few species from Brazil and Uruguay, which have uniform chromosome numbers (2n = 38). The recent cytogenetic data of Acromyrmex striatus (Roger, 1863), including its banding patterns, showed a distinct karyotype (2n = 22), similar to earlier studied Atta Fabricius, 1804 species. Karyological data are still scarce for the leafcutter ants and many gaps are still present for a proper understanding of this group. Therefore, this study aimed at increasing cytogenetic knowledge of the genus through the characterization of other six species: Acromyrmex balzani (Emery, 1890), Acromyrmex coronatus Fabricius, 1804, Acromyrmex disciger (Mayr, 1887), Acromyrmex echinatior (Forel, 1899), Acromyrmex niger (Smith, 1858) and Acromyrmex rugosus (Smith, 1858), all of which were collected in Minas Gerais – Brazil, except for Acromyrmex echinatior which was collected in Barro Colorado – Panama. The number and morphology of the chromosomes were studied and the following banding techniques were applied: C-banding, fluorochromes CMA3 and DAPI, as well as the detection of 45S rDNA using FISH technique. All the six species had the same chromosome number observed for already studied species, i.e. 2n = 38. Acromyrmex balzani had a different karyotype compared with other species mainly due to the first metacentric pair. The heterochromatin distribution also showed interspecific variation. Nevertheless, all the studied species had a pair of bands in the short arm of the first subtelocentric pair. The fluorochrome CMA3 visualized bands in the short arm of the first subtelocentric pair for all the six species, while Acromyrmex rugosus and Acromyrmex niger also demonstrated in the other chromosomes. The AT-rich regions with differential staining using DAPI were not observed. 45S ribosomal genes were identified by FISH in the short arm of the first subtelocentric pair in Acromyrmex coronatus, Acromyrmex disciger and Acromyrmex niger. The uniform chromosome number in the genus Acromyrmex (2n = 38) suggests that Acromyrmex striatus (2n = 22) should be transferred to a new genus. Other aspects of the chromosome evolution in ants are also discussed.
Cytogenetic data on the threatened leafcutter ant Atta robusta Borgmeier, 1939 (Formicidae: Myrmicinae: Attini)
(Comptes Rendus Biologies, 2015-08-24) Barros, Luı́sa Antônia Campos; Aguiar, Hilton Jeferson Alves Cardoso de; Teixeira, Gisele Amaro; Mariano, Cléa dos Santos Ferreira; Teixeira, Marcos da Cunha; Delabie, Jacques Hubert Charles; Pompolo, Silvia das Graças
The karyotype of the threatened ant species Atta robusta is described so as to establish the evolutionary relationships of this taxon with other leafcutter ants. Standard Giemsa staining, C-banding, NOR banding, fluorochromes CMA3/DAPI, Hsc-FA technique and Fluorescence in situ Hybridization (FISH) using 18S rDNA probe were conducted on a population from Aracruz, state of Espírito Santo, Brazil, allowing for comparisons with data available on Atta and other fungus-growing ant species. The diploid chromosome number observed for A. robusta was 2n = 22, and the karyotypic formula was 18m + 2sm + 2st. Heterochromatic blocks were observed in the centromeric region of most chromosomes, where one pair of metacentric chromosomes is characterized by a GC-rich heterochromatic band in the interstitial region of its long arm. The detection of 18S rDNA using FISH confirmed the presence of single NOR for A. robusta. This is the first report of rDNA 18S detection using FISH for leafcutter ants. The cytogenetic results of this study confirm the information available for Atta and allow us to confirm the conserved chromosome number, morphology and banding pattern within the genus for the taxa studied to date, which included species from three out of the four groups of Atta indicated by molecular data. The accumulation of cytogenetic data on fungus-growing ants enhances the understanding of the genomic evolutionary patterns of Atta, since it belongs to a group of recent origin between the most well studied ants. Cytogenetic data does not indicate restrictions in relocation or reintroduction in areas where populations were extinct due to the conserved karyotype. This study allows for cytogenetic comparison of A. robusta with other ants of Atta, emphasizing the importance of chromosomal information for species conservation.
Cytogenetic studies on populations of Camponotus rufipes (Fabricius, 1775) and Camponotus renggeri Emery, 1894 (Formicidae: Formicinae)
(PLoS One, 2017-05-16) Aguiar, Hilton Jeferson Alves Cardoso de; Barros, Luísa Antônia Campos; Alves, Danúbia Rodrigues; Mariano, Cléa dos Santos Ferreira; Delabie, Jacques Hubert Charles; Pompolo, Silvia das Graças
Two valid ant species, Camponotus rufipes and Camponotus renggeri, have recently been the subject of a broad discussion with reference to taxa synonymization. Both species are quite common among the Neotropical myrmecofauna and share some unique traits, such as the shape of the scape and the pilosity patterns of the tibiae and scapes. A single morphological trait can help distinguish these species; however, only a combination of different approaches can enlighten our view of the complex phylogenetic relationships prevailing in the different populations of these two taxa. Therefore, focusing on the taxonomic issues concerning these two species, a cytogenetic survey including 10 populations of C. rufipes and two populations of C. renggeri was performed. In order to better understand the extent of the relationship between C. rufipes and C. renggeri, two common Neotropical Camponotus species, C. atriceps and C. cingulatus were taken as outgroups. All four species of Camponotus that were studied had 2n = 40 chromosomes (4sm+34st+2t); however, the abundance of chromosome rearrangements observed, combined with several chromosome markers, suggest that C. rufipes and C. renggeri are two good distinct species although closely related. The already reported chromosome translocation 2n = 39 (1m+4sm+32st +2t) for C. rufipes has been found in different populations as in the unprecedented chromosome inversions found both in C. rufipes and in C. renggeri populations. Within the C. renggeri chromosome inversions, both the heterozygous state 2n = 40 (1m+3sm+34st+2t) and the homozygous state, 2n = 40 (2m+2sm+34st+2t) were identified. However, only het- erozygous specimens for chromosome inversions were found among C. rufipes, with karyotype configurations distinct from those found in C. renggeri, with 2n = 40 (1m+4sm+34st +2t). None of the populations studied showed signs of mosaic individuals. With respect to rDNA clusters, the 18S rDNA seemed to be more restricted inside the genome, as C. renggeri showed four 18S rDNA clusters, whereas, C. rufipes, C. atriceps, and C. cingulatus showed only two clusters. The chromosome locations of the 5S rDNA clusters were pointed for the first time in Formicidae, and showed itself to be more widely spread over the genome. By combining different chromosome banding approaches it was possible to demonstrate the crucial importance that chromosome inversions played on the karyotype evolution within these ants. The results also showed that chromosome translocations might be a consequence of the chromatin dynamic condition observed among Camponotus species. The homozygosis condition found in a C. renggeri from a Brazilian savanna population for chromosome inversions and the contrasting heterozygous condition for a different kind of chromosome inversion in C. rufipes from the Brazilian coastal rainforest, opens the window for a chromosome race hypothesis within the group C. renggeri and C. rufipes. The wide distribution, rich ecological interactions, genetic diversity, and morphological variability among C. renggeri and C. rufipes justify questioning of the actual taxonomic status of these species. The answer of this puzzle is clear when observing the number of 18S rDNA clusters of these ants, as C. rufipes has only two clusters whereas C. renggeri has four.
Epidermal glands in the abdomen of a basal ant Dinoponera lucida (Formicidae: Ponerinae)
(Microscopy Research And Technique, 2008-09-24) Serrão, José Eduardo; Castro, Rafael Cunha A.; Zanuncio, José Cola; Mariano, Cléa Santos Ferreira; Delabie, Jacques Hubert Charles
The basal ant Dinoponera (Hymenoptera: Ponerinae) has lost the morphologic queen caste so that all females may be potential reproductive individuals, and the nestmate recognition results from cuticular hydrocarbons cues. However, data about the origin of that substance in Ponerinae ants are scarce. This study reports the occurrence of epidermal glands in the abdomen of the ant Dinoponera lucida. In this ant, the epidermis of the abdominal sternites has tall cells with well-developed nucleus contrasting with flattened and collapsed epidermis in the tergites, suggesting a glandular function in the epidermis of the sternites. The possible role of the glandular epidermis in the synthesis of cuticular hydrocarbons for the nestmate recognition is discussed. Microsc. Res. Tech., 2009. © 2008 Wiley-Liss, Inc.
Glandular epithelium as a possible source of a fertility signal in Ectatomma tuberculatum (Hymenoptera: Formicidae) Queens
(PLoS One, 2010-04-19) Hora, Riviane Rodigues da; Delabie, Jacques Hubert Charles; Santos, Carolina Gonçalves dos; Serrão, José Eduardo
The wax layer covering the insect's cuticle plays an important protective role, as for example, uncontrolled water loss. In social insects, wax production is well-known in some bees that use it for nest building. Curiously, mated-fertile queens of the ant Ectatomma tuberculatum produce an uncommon extra-wax coat and, consequently queens (mated-fertile females) are matte due to such extra cuticular hydrocarbon (CHC) coat that covers the cuticle and masks the brightness of the queens' cuticle while gynes (virgin-infertile queens) are shiny. In this study, histological analysis showed differences in the epidermis between fertile (i.e., queens or gynes with highly ovarian activity) and infertile females (gynes or workers with non developed ovaries). In fertile females the epidermis is a single layer of cubic cells found in all body segments whereas in infertile females it is a thin layer of flattened cells. Ultrastructural features showed active secretory tissue from fertile females similar to the glandular epithelium of wax-producing bees (type I gland). Different hypotheses related to the functions of the glandular epithelium exclusive to the E. tuberculatum fertile queens are discussed.
Impacto das capinas mecânica e química do sub-bosque de Eucalyptus grandis sobre a comunidade de formigas (Hymenoptera: Formicidae)
(Revista Árvore, 2004-02-17) Ramos, Lucimeire de Souza; Zanetti, Ronald; Marinho, Cidália Gabriela Santos; Delabie, Jacques Hubert Charles; Schlindwein, Marcelo Nivert; Almado, Roosevelt de Paula
O efeito das capinas mecânica e química do sub-bosque em plantações de eucaliptos e as conseqüências desses tratamentos sobre a comunidade de formigas foram avaliados no município de Bom Despacho, Minas Gerais, Brasil. As formigas foram coletadas com o extrator de Winkler. Coletou-se um total de 86 espécies, pertencentes a seis subfamílias. Oito dias após as capinas, o número de espécies reduziu-se de um quarto para os dois tipos de capina. Sessenta dias após, o número de espécies tendeu a retornar ao estágio inicial, verificando-se que a eliminação do sub-bosque causa efeito deletério imediato, de igual intensidade e de pouca duração sobre a comunidade de formigas. As razões das variações observadas serão discutidas.
Intramandibular glands in different castes of leaf‐cutting Ant, Atta laevigata (Fr. Smith, 1858) (Formicidae: Attini)
(Microscopy Research and Technique, 2015-04-18) Martins, Luiza Carla Barbosa; Della Lucia, Terezinha Maria Castro; Gonçalves, Wagner Gonzaga; Delabie, Jacques Hubert Charles; Zanuncio, José cola; Serrão, José Eduardo
Intramandibular glands have been poorly studied in polymorphic ants, where the differences between castes were unsufficiently scrutinized. Leaf-cutting ants possess one of the most complex systems of communication and labor division, which is polymorphic well as age polyethism, and makes them an ideal model for the study of intramandibular glands. This study has investigated the occurrence of intramandibular glands in female castes and subcastes of Atta laevigata. The mandibles of the queen, medium, and minor workers, and soldiers were sub- mitted to histological, histochemical, ultrastructural, and morphometric analyses. The class-3 gland cells and the epidermal gland with a reservoir were found in all the castes. The queens and soldiers showed a higher number of class-3 gland cells, distributed within the mandible as well as a greater gland size in comparison to the workers. The histochemical tests, periodic acidSchiff (PAS), mercury-bromophenol, and Nile blue, were similar for the class-3 gland cells and epidermal glands with a reservoir. However, the tests evidenced differences between the castes, with carbohydrates strongly positive in all of them, whereas neutral lipids were found in the queen and soldiers. The protein was weakly positive in the queen, whereas in the soldier, medium, and minor workers these reactions were strongly positive in the intramandibular glands. Our findings in A. laevigata suggest that intramandibular glands are directly involved in labor division and consequently in chemical communication between the castes.
Limited effects of low-intensity forest management on ant assemblages in southwestern Amazonian forests
(Biodiversity and Conservation, 2017-05-23) Oliveira, Marco Antônio; Miranda, Patrícia Nakayama; Baccaro, Fabricio Beggiato; Morato, Elder Ferreira; Delabie, Jacques Hubert Charles
One important strategy to conciliate forest conservation and economic development is the use of reduced-impact logging techniques. Here we evaluated the effects of low-intensity forest management on ant assemblages and vegetation structure in a managed area in the southeast of Acre State, Brazil. Ground-dwelling and arboreal ants, and several forest-structure descriptors were sampled in nine paired areas located in control (unlogged) and logged areas in 2005, 2007 and 2009. None of the forest structure predictors were related with either the treatment or the time since logging. However, some ant assemblage’ descriptors were related with logging activities. Arboreal and ground-dwelling ant species richness was similar between unlogged and logged areas, but more ground-dwelling ant species were found in areas logged in 2005 compared with areas logged in 2009. Ground-dwelling ant assemblage composition differed between treatments (logged and unlogged) and year of logging, but species composition heterogeneity was similar between areas. Arboreal ant assemblage composition was not related with treatment and year of logging, but assemblage composition was more heterogeneous in managed areas, suggesting that species that forage on the understory vegetation may be more resilient than ground-dwelling species. The general results of functional group approach suggest that changes of species composition between control and managed areas are more related with differences in ant species occurrence than ant species richness. Selective logging had limited effect on both vegetation descriptors and ant assemblage structure, suggesting that the conciliation of impact reduction techniques with low intensity extraction seems a promising alternative for sustainable logging activity in tropical forests.
Neuropile organization in the brain of Acromyrmex (Hymenoptera, Formicidae) during the post-embryonic development
(Brazilian Archives of Biology and Technology, 2004-08) Soares, Paula Andréa Oliveira; Delabie, Jacques Hubert Charles; Serrão, José Eduardo
Neuropile is the region of the central nervous system where the synapses an d neurons branching occur. During the development of an holometabolous insect can occurs break of the neurons fibers forming new axon and dendrites and their distribution in brain neuropile is organized so as to reflect specific nervous functions of adult insects. The components of this organization were observed and discussed in this study in the ant Acromyrmex octospinosus, evidencing similar features to those described for A. subterraneus subterraneus, among other insects for the which ones this information is available.
Occurrence of pre-nucleolar bodies and 45S rDNA location on the chromosomes of the ant Mycocepurus goeldii (Forel) (Formicidae, Myrmicinae, Attini)
(Hereditas, 2011-12-21) Barros, Luísa Antônia Campos; Aguiar, Hilton Jeferson Alves Cardoso De; Andrade-Souza, Vanderly; Mariano, Cléa Dos Santos Ferreira; Delabie, Jacques Hubert Charles; Pompolo, Silvia Das Graças
The ant Mycocepurus goeldii (Forel) is known for having a relict karyotype with low chromosome number and the present study help the understanding of this ant cytogenetics by describing the occurrence of pre-nucleolar bodies in their chromosomes using impregnation with silver nitrate (Ag-NOR) and the location of 45S rDNA sites by means of the FISH (fluorescent in situ hybridization) technique. Several spots were observed surrounding all chromosomes when submitted to the Ag-NOR technique. These unusual markings were observed in both chromatids of metaphase and early anaphase chromosomes, and are associated to the presence of pre-nucleolar bodies, allowing the observation of the phenomenon of nucleologenesis. Although recent studies have shown that all chromosomes of M. goeldii exhibit centromeric or pericentromeric markings for the CMA3 fluorochrome, the FISH technique indicated the presence of 45S rDNA in only one pair of chromosomes that differed in the number of CMA3 markings observed for this species, pointing that the other markings observed with this fluorochrome do not match the sequences in ribosomal genes.
Structural changes in arboreal ant assemblages (Hymenoptera: Formicidae) in an age sequence of cocoa plantations in the south‐east of Bahia, Brazil
(Austral Entomology, 2015-08) Della Lucia, Terezinha Maria Castro; Conceição, Eltamara Souza da; Delabie, Jacques Hubert Charles; Costa‐Neto, Antonio de Oliveira; Majer, Jonathan David
A study of succession of ant species in plantations of different ages and development may assist with our understanding of the dynamics of their assemblages. The aim of this study was to characterise the relationship between development of Brazilian cocoa plantations and the nature of their dominant ant assemblages. A chronosequence of cocoa plantations aged 1, 3, 4, 8, 15 and 33 years was sampled by several methodologies. Data were analysed in terms behavioural dominance and Berger‐Parker's dominance index (here based on frequency data), and also by principal component analysis and analysis of co‐occurrence. Apart from lower numbers of species being found in the 1‐year‐old plantation, there was no consistent trend in ant richness with plantation age. According to the criteria we adopted, only one species reached behavioural dominance in most age classes of plantation, although this increased to three in the 8‐year‐old one, before declining to zero in the oldest plantation. No species reached Berger‐Parker's dominance in the youngest plantation, whereas all other age classes contained one to three dominants. Particular species showed non‐age‐related variations in their degree of Berger‐Parker's dominance and this could in part be related to which species initially colonised the plantation. Principal component analysis axis 1 was partly related to plantation age, indicating an age‐related change in assemblage composition. Ant species co‐occurrence could only be effectively detected in cocoa plantations from 3 to 15 years of age. The arboreal ant assemblage is dynamic in nature, with the competitive hierarchy among species oscillating along the cocoa development chronosequence. The assemblage structure could be influenced by the initial founding ants, as well as by the invasive Monomorium floricola.
Temporal variation of vitellogenin synthesis in Ectatomma tuberculatum (Formicidae: Ectatomminae) workers
(Journal of Insect Physiology, 2011-04-15) Azevedo, Dihego Oliveira; Zanuncio, José Cola; Delabie, Jacques Hubert Charles; Serrão, José Eduardo
Workers of the ant species Ectatomma tuberculatum (Ectatomminae) have active ovaries and lay eggs that are eaten by the queen and larvae (trophic eggs). Vitellogenins are the main proteins found in the eggs of insects and are a source of nutrients. The aim of this study was to characterize the period of vitellogenin production in workers of E. tuberculatum. The vitellogenin was identified from queen and worker eggs by SDS-PAGE. Anti-vitellogenin antibodies were obtained and used to detect this protein in the fat body and haemolymph of workers at different ages. Vitellogenin from E. tuberculatum consists of two polypeptides of 31 and 156 kDa. In the eggs of queens, the 156 kDa polypeptide is cleaved into two subunits of 36 and 123 kDa. The analysis of the haemolymph of workers showed that the secretion of vitellogenin varies with age. The secretion is initiated around the fifth day after emergence, with peak production from days 20 to 60, and stops around day 100. The variation in production is related to the different activities performed by the workers within the colony, suggesting that vitellogenin may have an important role in maintaining age polyethism.