Navegando por Autor "Fernandes, Geraldo Wilson"

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Diversity of Hemiptera (Arthropoda: Insecta) and their natural enemies on Caryocar brasiliense (Malpighiales: Caryocaraceae) trees in the Brazilian Cerrado
(Florida Entomologist, 2016) Leite, Germano Leão Demolin; Veloso, Ronnie Von dos Santos; Zanuncio, José Cola; Alonso, Jatnel; Ferreira, Paulo Sérgio Fiuza; Almeida, Chrystian Iezid Maia; Fernandes, Geraldo Wilson; Serrão, José Eduardo
The Cerrado occupies about 23% of the Brazilian territory and is characterized by great diversity of plants and insects and a great degree of endemism, and Caryocar brasiliense A. St.-Hil. (Malpighiales: Caryocaraceae) is widely distributed in this region. The diversity and abundance of hemipterans and their natural enemies were studied on trees of C. brasiliense in the Cerrado, pasture, and anthropic area in Montes Claros, Minas Gerais State, Brazil. We observed 1 rare, 8 common, and 1 frequent species of sucking insects; and 2 rare, 7 common, and 6 frequent species of natural enemies. Sucking insects and their natural enemies were most abundant in the pasture and least abundant in the Cerrado. Increasing diversity indices and numbers of species and individuals of sucking insects were followed by similar trends in the populations of natural enemies. Increasing populations of sucking insects led to greater numbers of individuals of ants, green lacewings, predator thrips, and ladybeetles. Aluminum level positively affected the number of species and individuals, and the pH of the soil reduced those of sucking insects. Leafhoppers had greater numbers on plants on soils with low pH values and high aluminum levels, but the opposite was noted for the aphids.
Habitat complexity and Caryocar brasiliense herbivores (Insecta: Arachnida: Araneae)
(Florida Entomologist, 2012-12) Soares, Marcus Alvarenga; Fernandes, Geraldo Wilson; Zanuncio, José Cola; Almeida, Chrystian Iezid Maia E; pt-BRFerreira, Paulo Sérgio Fiúza; Soares, Marcus Alvarenga; Veloso, Ronnie Von dos Santos
Caryocar brasiliense Camb. (Malpighiales: Caryocaraceae) trees have a wide distribution in the cerrado. This plant is protected by federal laws and is left in deforested areas of the cerrado. This situation increases the damage to leaves, flowers, and fruits from chewing insects. We studied the effect of habitat complexity and plant architecture on the diversity and abundance of the Lepidoptera, Coleoptera, and Hymenoptera herbivores and their predators on trees of C. brasiliense in cerrado, pasture, and on the Campus of the Federal University of Minas Gerais. We observed 13 rare, 2 common, and 1 constant species of herbivores insects; and 3 rare, 8 common, and 1 constant species of predators on trees. Higher diversities and number of species of herbivores insects and their predators were observed in pasture than in the cerrado and on the campus of the Federal University of Minas Gerais. Herbivorous insects were most abundant in pasture and least abundant on the university campus. Predators were most abundant in pasture and least abundant in the cerrado. Ants, spiders, and predatory bugs are important in the reduction of the defoliators and leaf miners insects. The percentages of defoliation and populations of defoliators and ants were higher on C. brasiliense trees with wider crowns. We found a positive correlation of soil aluminum concentration with percent defoliation and numbers of lepidopteran leaf miners. On the other hand, increased soil pH was correlated with reduction in percent defoliation and numbers of lepidopteran leaf miners.
Seasonal abundance of galling Insects (Hymenoptera) on Caryocar brasiliense (Malpighiales: Caryocaraceae) trees in the cerrado
(Florida Entomologist, 2013-09) Veloso, Ronnie Von Dos Santos; Leite, Germano Leão Demolin; Zanuncio, José Cola; Fernandes, Geraldo Wilson; Almeida, Chrystian Iezid Maia; Pereira, José Milton Milagres; Serrão, José Eduardo; Soares, Marcus Alvarenga
Caryocar brasiliense Camb. (Malpighiales: Caryocaraceae) trees have a wide distribution in the Cerrado, a tropical Brazilian savanna, with high diversity and endemism. This plant is protected by federal laws and is untouched in deforested areas of the Cerrado. This situation increases the damage to leaves from galling insects (Hymenoptera). We studied populations of galling insects and their natural enemies on C. brasiliense trees for 3 successive yr during each season in the Cerrado. A globoid gall-inducing Eurytoma sp. (Hymenoptera: Eury- tomidae) and its parasitoid Sycophila sp. (Hymenoptera: Eurytomidae) adults and predator Zelus armillatus (Lepeletier and Serville) (Hemiptera: Reduviidae) on the leaves were most abundant in the winter. The numbers of vein galls correlated negatively with the numbers of discoid and spherical galls, and the numbers of spherical galls correlated negatively with the numbers of discoid galls on C. brasiliense leaflets. Increased percentages of defoliation were correlated with reductions in the percentages of leaflets with total galls and leaflet area with total galls. Increased numbers of Sycophila sp. and decreased numbers of Ablerus magistretti Blanchard (Hymenoptera: Aphelinidae) were correlated with reduction in the numbers of Eurytoma sp. Numbers of Quadrastichus sp. (Hymenoptera: Eulophidae) and A. magistretti correlated negatively with the numbers of Sycophila sp. Increased numbers of Z. armillatus were correlated with reduction in the numbers of Eurytoma sp. and its galls and parasitoids. We concluded that this differential temporal distribution of galling insects and their natural enemies was influenced by plant phenology and time of colonization on C. brasiliense leaves.
Seasonal abundance of hemipterans on Caryocar brasiliense (Malpighiales: Caryocaraceae) trees in the cerrado
(Florida Entomologist, 2012-12) Leite, Germano Leão Demolin; Zanuncio, José Cola; Fernandes, Geraldo Wilson; Almeida, Chrystian Iezid Maia; Ferreira, Paulo Sérgio Fiúza; Alonso, Jatnel; Serrão, José Eduardo; Veloso, Ronnie Von dos Santos
Caryocar brasiliense Camb. (Malpighiales: Caryocaraceae) trees have a wide distribution in the cerrado. This plant is protected by federal laws and is untouched in deforested areas of the cerrado. Under these circumstances, the damage to leaves, flowers, and fruits from sucking hemipterans has increased. We studied populations of sucking insects and their predators on C. brasiliense trees in the cerrado during each season for 3 successive years. The numbers of sucking insect individuals on C. brasiliense trees were similar among the seasons of the year. However, the highest number of species and greatest diversity occurred in winter. Predators were most abundant in spring and winter, with highest diversity and number of species in winter. We observed 7 rare, 2 common, and 1 constant species of sucking insects; and 4 rare, 8 common, and 1 constant species of predators on C. brasiliense trees. The greatest numbers of various sucking insect species were observed by seasons as follows: Aconophora sp. (Membracidae) on fruits and Frequenamia sp. (Cicadellidae) on leaves in the winter; Aphis gossypii (Glover) (Aphididae) and Mahanarva sp. (Cercopidae) in the spring; and Dikrella sp. (Hemiptera: Cicadellidae) on the leaves in the summer and autumn. For predators, Crematogaster sp. (Hymenoptera: Formicidae) had the lowest abundance on the leaves in the summer, and highest abundance in the flowers in the winter and spring, while in spring it was most abundant on the fruits, and in the autumn Trybonia sp. (Thysanoptera: Phlaeothripidae) on the leaves was the most abundant. Higher number of ants Crematogaster sp. was observed in Caryocar brasiliense trees that presented large numbers of Dikrella sp.. Higher numbers of predators Trybonia sp., Chrysoperla sp. (Neuroptera: Chrysopidae), and total of predator thrips were associated with decreasing numbers of Dikrella sp., A. gossypii, and total of sucking insects respectively. The increase in the numbers of individuals and species of predators were correlated with the reduction of these same ecological parameters of the sucking insects. We argue that this differential temporal distribution of sucking insects and their predators was influenced for phenology of plant and weather.
Sex-mediated herbivory by galling insects on Baccharis concinna (Asteraceae)
(Revista Brasileira de Entomologia, 2006-07) Carneiro, Marco Antonio A.; Fernandes, Geraldo Wilson; Souza, Og F. F. de; Souza, Wyller Vicente M.
The interaction patterns between the dioecious shrub Baccharis concinna Barroso (Asteraceae) and its speciose galling insect community were studied in southeastern Brazil. Two hypotheses were tested in this study: "the differential reproduction and growth hypothesis" that predicts that male plants present fewer reproductive structures and are larger than female plants; and the 'sex-biased herbivory hypothesis' that predicts that male plants support a larger abundance of insect galls than female plants. Plants did not show sexual dimorphism in growth (= mean leaf number). However, male plants had longer shoots and a lower average number of inflorescences than female plants. These results corroborate the hypothesis that male plants grow more and reproduce less than female plants. No statistically significant difference was found in the number of galls between male and female plants, but a sex by environmental effect on gall number was detected. When each species of galling insect was individually analyzed per population of the host plant, the rates of attack varied between sex and population of the host plant, and they were highly variable among the species of galling insects. These results highlight the importance of the interaction between sex and environment in the community structure of galling insects and indicate that other variables besides host sex may influence the patterns of attack by galling herbivores.
Topsoil depth influences the recovery of rupestrian grasslands degraded by mining
(Sociedade Brasileira de Ciência do Solo, 2021-09-20) Rezende, Lina Andrade Lobo; Fernandes, Geraldo Wilson; Braga, Ramon de Paula; Dias, Luiz Eduardo; Gomes, Vanessa Matos
Close association of iron mining and ferruginous rupestrian grassland places this ecosystem in a special condition of vulnerability, with a large number of degraded areas requiring restoration. Seedling transplantation and topsoil translocation can be used to recover native vegetation in degraded areas. This study aimed to experimentally test the application of two different topsoil depths (0.20 and 0.40 m) in a degraded area. We assessed the vegetation’s natural recovery and the survival of transplanted native species from rescue operations in four 200 m 2 plots established in each topsoil depth. There was no influence of topsoil depth on the plant species survival, while the vegetation cover was greater on the thicker topsoil. However, exotic species with invasive potential contributed substantially to this vegetation cover, requiring management planning. Some planted native species stood out for their survival ability in the topsoil 49 months after planting. Application of 0.20 m topsoil layer showed to be able to provide native species’ natural recovery and survivorship.