Orientador: Luiz Carlos Forti / Banca: Odair Correa Bueno / Banca: Ivone Paschoal Garcia / Abstract: The objective of this paper was to have a better understanding of plant-ant-symbiotic fungus interaction focusing on foraging behavior of Atta sexdens rubropilosa workers during plant selection. Physical and chemical substrate factors were approached which can have a role on foraging material selection for symbiotic fungus cultivation besides defoliating localization in artificial plants. Tested hypothesis was that besides chemical characteristics physical stimulus and leaves localization in a plant also play a very important role in substrate selection by A. sexdens rubropilosa workers. Different shape and thickness material was used (different leaves, paper leaves with different shapes and thickness impregnated in plant extract and artificial plants). The aim was to verify the existence of physical and chemical resistance, leaf palatability and defoliating localization. Wood plants Actinostemon communis, Alchornea triplinervea, Croton floribundus, Faramea cyanea, were offered to workers and evaluated 4 according to mechanical resistance of cut and palatability. Each plant was offered individually in big disc shape (2,5cm diameter), small disc shape (0,5cm diameter) and whole leaves. Other studies were carried out for detecting physical and chemical stimulus through simulated cuts and impregnation of plant extract in paper leaves with different thickness making it possible to evaluate the combinations between physical and chemical substrate characteristics. Defoliating localization in plants was studied when offering artificial plants with four levels where either wood plant or Ligustrum sp. leaves was attached. Defoliating intensity was measured by the number of fallen leaves by ants. In order to study wood plant attractiveness small disc shaped leaves (0,5cm diameter) were offered at the same time for ants in laboratory. The end of the experiment was determined either by the carrying... (Complete abstract, click electronics address below). / Mestre

Made available in DSpace on 2014-06-11T19:28:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-02-10Bitstream added on 2014-06-13T20:37:43Z : No. of bitstreams: 1 noronhajunior_nc_me_botfca.pdf: 814511 bytes, checksum: f0ba517a59245727f01aed36f56871ba (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Empresa Privada / The objective of this paper was to have a better understanding of plant-ant-symbiotic fungus interaction focusing on foraging behavior of Atta sexdens rubropilosa workers during plant selection. Physical and chemical substrate factors were approached which can have a role on foraging material selection for symbiotic fungus cultivation besides defoliating localization in artificial plants. Tested hypothesis was that besides chemical characteristics physical stimulus and leaves localization in a plant also play a very important role in substrate selection by A. sexdens rubropilosa workers. Different shape and thickness material was used (different leaves, paper leaves with different shapes and thickness impregnated in plant extract and artificial plants). The aim was to verify the existence of physical and chemical resistance, leaf palatability and defoliating localization. Wood plants Actinostemon communis, Alchornea triplinervea, Croton floribundus, Faramea cyanea, were offered to workers and evaluated 4 according to mechanical resistance of cut and palatability. Each plant was offered individually in big disc shape (2,5cm diameter), small disc shape (0,5cm diameter) and whole leaves. Other studies were carried out for detecting physical and chemical stimulus through simulated cuts and impregnation of plant extract in paper leaves with different thickness making it possible to evaluate the combinations between physical and chemical substrate characteristics. Defoliating localization in plants was studied when offering artificial plants with four levels where either wood plant or Ligustrum sp. leaves was attached. Defoliating intensity was measured by the number of fallen leaves by ants. In order to study wood plant attractiveness small disc shaped leaves (0,5cm diameter) were offered at the same time for ants in laboratory. The end of the experiment was determined either by the carrying... (Complete abstract, click electronics address below).

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The growing demand for forest products has enabled the increase in areas planted to trees in Brazil. Eucalyptus is a fast growing tree species being cultivated on a large scale, however, with increasing of Eucalyptus sp. plantation, entomological problems tend to increase. The defoliating caterpillars represent an important group of insects that are harmful to forest plantations. Thus, this study aims at characterize an outbreak of the Nystalea nyseus (Cramer, 1775) species, as well as its biology aspects and natural enemies. This study was conducted in a seminal plantation of Eucalyptus saligna Smith in the city of São Sepé, Rio Grande do Sul, Brazil. To evaluate the outbreak, a sampling was carried out by using the transect method. Defoliating caterpillars were collected from different instars and pupae of this species and they were sent to the laboratory under conditions at 25°C ± 1°C, 80% relative humidity and 12- hour photophase. The biological aspects evaluated were: color and morphology of eggs, duration of pre-pupal and pupae stage, sex ratio and lifespan adults. A visual inspection of eucalyptus plantation was conducted to catch potential natural enemies. The results showed the presence of attack on all the stands. The eggs are greenish, and after 24 hours, became light red. They have an average length of 1.17 (± 0.387) mm and a width of 1.20 (± 0.229) mm, and as an average incubation period of six days. Pre-pupal stage lasted 3.53± 0.53 days and pupal stage lasted 14.02 (±1.23) and 15.12 (±1.08) days for females and males, respectively. The length (mm), width (mm) and weight (g) of pupae were higher for females, however, with no significant difference. The adult sex ratio was 0.62 females per male and lifespan was 7.63 days for females and 5.47 for males. The following predatory species were registered: Podisus nigrispinus (Dallas, 1851), Brontocoris tabidus (Signoret, 1863) and Alcaeorrhynchus grandis (Dallas, 1851) all belonging to the Heteroptera order, Pentatomidae family. The present paper for this first time reports an outbreak of this species of eucalyptus to Rio Grande do Sul, State, Brazil and extends the range of information about the biology of Nystalea nyseus. For the first time, predatory species are registered as natural enemies. / A crescente demanda por produtos florestais tem propiciado o aumento das áreas plantadas no Brasil. O eucalipto é uma espécie florestal de rápido crescimento e é cultivado em larga escala, porém com o aumento das áreas de plantio com Eucalyptus sp., os problemas entomológicos tendem a aumentar. As lagartas desfolhadoras representam um grupo importante de insetos daninhos em plantios florestais. Nesse sentido, o objetivo deste trabalho foi caracterizar um surto da espécie Nystalea nyseus (Cramer, 1775), bem como aspectos da sua biologia e inimigos naturais. Este estudo foi realizado em um plantio seminal de Eucalyptus saligna Smith localizado no município de São Sepé, Rio Grande do Sul. Para avaliar o surto foi realizada uma amostragem utilizando o método do transecto. Foram coletadas lagartas de diferentes ínstares e pupas dessa espécie e encaminhadas para o laboratório, sob condições controladas temperatura de 25°C ± 1°C, umidade relativa de 80 % e fotofase de 12 horas. Os aspectos biológicos avaliados foram: coloração e morfologia dos ovos, duração do período de pré-pupa e pupa, razão sexual e longevidade de adultos. Realizou-se uma inspeção visual no plantio de eucalipto objetivando a captura de possíveis inimigos naturais. Como resultados constatou-se a presença de ataque em todos os talhões avaliados. Os ovos obtidos em laboratório apresentaram coloração esverdeada e após 24 horas, tornaram-se vermelho claro. Apresentam, em média, comprimento de 1,17 (± 0,387) mm e largura de 1,20 (± 0,229) mm, assim como um período médio de incubação de seis dias. A fase da pré-pupa teve duração de 3,53 (±0,53) dias e a de pupa 14,02 (±1,23) e 15,12 (±1,08) dias para fêmeas e machos, respectivamente. O comprimento (mm), largura (mm) e peso (g) das pupas foram maiores para fêmeas, porém sem diferença significativa. A razão sexual de adultos obtida em laboratório foi de 0,62 fêmeas para cada macho e a longevidade média foi de 7,63 dias para fêmeas e 5,47 para machos. Foram registradas a ocorrência das seguintes espécies predadoras: Podisus nigrispinus (Dallas, 1851), Brontocoris tabidus (Signoret, 1863) e Alcaeorrhynchus grandis (Dallas, 1851) todas pertencentes à ordem Heteroptera, família Pentatomidae. O presente trabalho registra pela primeira vez um surto dessa espécie em eucalipto para o Rio Grande do Sul e amplia o conjunto de informações a respeito da biologia de Nystalea nyseus. Registram-se pela primeira vez espécies predadoras como inimigos naturais.