Submitted by (edna.saturno@ufrpe.br) on 2016-11-28T14:10:41Z No. of bitstreams: 1 Mariana Oliveira Breda.pdf: 588678 bytes, checksum: dfbffb2bf31e84d654f1e337dae28971 (MD5) / Made available in DSpace on 2016-11-28T14:10:41Z (GMT). No. of bitstreams: 1 Mariana Oliveira Breda.pdf: 588678 bytes, checksum: dfbffb2bf31e84d654f1e337dae28971 (MD5) Previous issue date: 2011-02-01 / Aphis gossypii Glover is one of the major pest of cotton in Brazil, causing direct and indirect damage through viruses transmission. In alternative production systems, the control of this pest is carried out by natural biological control and by application of botanical insecticides. However, the performance of A. gossypii, its natural enemies and insecticides may be affected by different features of cotton cultivars, as the tricomas density. The objectives of this study were examine the interactions between white (BRS 8H and BRS 201) and colored fiber cotton cultivars (BRS Verde, BRS Safira and BRS Rubi), botanical insecticide (Azamax®, castor bean oil emulsion, aqueous extract of neem seeds, Eucalyptus citrioda Hook and E. staigeriana essential oils), A. gossypii and its natural enemy Cycloneda sanguinea (L.).Tested cultivars did not influence the development and feeding preference of A. gossypii, the locomotion and search ability of C. sanguinea and the effectiveness of tested botanical insecticides. The essential oils of E. staigeriana e E. citriodora showed no decrease in pest population and caused severe phytotoxicity in all cotton cultivars. Azamax® showed A. gossypii mortality ranging between 64 and 100%, and negative instantaneous growth rate (ri), from the concentration of 1.25%. For aqueous extract of neem seeds aphid mortality ranged between 12 and 92% and the ri was negative from concentration above 2.5%. Castor bean oil emulsion had low toxicity, with mortality rates ranging between 8 and 68% and negative ri, from concentration of 3.0%. Azamax® 0.25 and 1.25%, aqueous extract of neem seeds 2.25% and castor bean oil emulsion 3.0% showed high mortality to larvae of the 1st and 4th instars of C. sanguinea preventing the emergence of adults. / Aphis gossypii Glover constitui uma das principais pragas do algodoeiro no Brasil, causando danos diretos e indiretos através da transmissão de viroses. Em sistemas alternativos de produção, o controle dessa praga é mediado pelo controle biológico natural e a aplicação de inseticidas botânicos. Entretanto, a ação desse inseto, dos seus inimigos naturais e dos inseticidas utilizados pode ser influenciada por características das cultivares de algodoeiro, como a densidade de tricomas. Os objetivos desse trabalho foram analisar as interações de cultivares de algodão de fibra branca (BRS 8H e BRS 201) e colorida (BRS Verde, BRS Safira e BRS Rubi), inseticidas botânicos (Azamax®, extrato aquoso de nim, óleo de mamona e óleos essenciais de Eucalyptus staigeriana Hook e E. citriodora), A. gossypii e Cycloneda sanguinea (L.), um dos principais inimigos naturais desse pulgão no Brasil. Observou-se que de maneira geral, as cultivares testadas não influenciaram o desenvolvimento e a preferência alimentar de A. gossypii, a locomoção e capacidade de busca de C. sanguinea e a eficiência dos inseticidas botânicos testados. Os óleos essenciais de E. staigeriana e E. citriodora não provocaram redução na população da praga e causaram intensa fitotoxidade em todas as cultivares de algodão. Azamax® apresentou mortalidade de A. gossypii, entre 64 e 100%, e taxa instantânea de crescimento (ri) negativa, a partir da concentração de 1,25%. Para o extrato aquoso de nim a mortalidade variou entre 12 e 92% e as ri foram negativas, a partir da concentração de 2,5%. O óleo de mamona teve baixa toxicidade, com mortalidade variando entre 8 e 68% e ri negativas a partir da concentração de 3,0%. Azamax® a 0,25 e 1,25%, extrato aquoso de nim a 2,25% e óleo de mamona a 3,0% causaram mortalidade elevada para larvas de 1° e 4° ínstares de C. sanguinea, inviabilizando a emergência de adultos.

Predatory Ground beetles (Coleoptera: Carabidae) and Lady beetles (Coleoptera: Coccinellidae) are two of the most diverse groups found in wheat agroecosystems, globally. These groups are important from both an economic and ecological perspective due to their natural services provision. The effect of wheat agroecosystem management on species diversity, abundance, biomass and composition in South Africa is not yet documented, and there is no existing data indicating which predatory carabid and coccinellid species provides essential ecosystem services and bioindicator roles. Therefore, we examined the effects of organic, conventional and intercropped agroecosystems on ground beetle and lady beetle abundance, dried weight (biomass), composition and diversity. Sampling of wheat agroecosystems was conducted in three systems i.e. organic, conventional and organic intercropped. Post-hoc Tukey test indicated a statistically significant difference between species diversity, biomass and abundance in organic and intercropped systems compared to the conventional systems. Regression analysis indicated significant positive correlation between aphid’s density and predatory carabid and coccinellid beetles in the intercropped systems. Amongst the weather factors temperature influenced aphid density and carabid and coccinellid beetles’ abundance. PCA (Principal Component Analysis) revealed significant positive correlation between individual biomass and cropping system. Conventional system showed a negative correlations with carabid and coccinellid individual biomass. We found that some carabid and coccinellid species can be used to measure the quality of agroecosystems. This study provides a fundamental basis for identification and monitoring of carabid and coccinellid species and their role as bioindicators of ecological disturbance. The identified bioindicator species in this study can assist in developing conservation and biomonitoring strategies within agroecosystems. / Agriculture and  Animal Health / M. Sc. (Agriculture)