Efeitos de fungicidas utilizados em pepino sobre Aphis gossypii Glover, 1877 (Hemiptera: Aphididae) e Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae)

• Ano de defesa: 2007
• Autor(a) principal: Costa, Ronelza Rodrigues da
• Orientador(a): Carvalho, César Freire
• Banca de defesa: Silva, Rogério Antônio, Carvalho, Geraldo Andrade
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: UNIVERSIDADE FEDERAL DE LAVRAS
• Programa de Pós-Graduação: DEN - Programa de Pós-graduação
• País: BRASIL
• Palavras-chave em Português: Cucurbitaceae; Pulgão-do-algodoeiro; Fungicidas; Crisopídeo; Cucumis sativus; Cotton aphid; Fungicide; Green lacewing
• Área do conhecimento CNPq: CNPQ_NÃO_INFORMADO
• Link de acesso: https://repositorio.ufla.br/handle/1/2741

The effect of some fungicides utilized in cucumber crop on the aphid Aphis gossypii Glover and the predator Chrysoperla externa (Hagen) was evaluated. Leaf disks of cucumber arranged on Petri dishes received the products via spraying by means of the Potter tower and on each one, a first-instar nymph was put. The toxicity of the fungicides to C externa was evaluated as related with the ways of contact application or ingestion of the compounds by second-instar, which was fed nymphs of A. gossypii. The experiments were conducted under controlled conditions at 25±2oC; RH: 70±10% and 12h photophase in a completely randomized design with four treatments, with 45 replicates for the experiment of aphid biology and for C. externa, six replicates, each plot being made up of four larvae. The fungicides utilized and the dosages in g a i.L-1 were: sulphur 800 PM (1.6), mancozeb 800 PM (1.6) and copper oxichloride 840 PM (1.49). The control was composed of water. The chemicals evaluated did not influence the nymphal duration and survival rate, duration of the adult stage, pre-reproductive and reproductive periods of A. gossypii, however, caused the increase of the duration of the biological cycle, except mancozeb. There was an effect of the application of sulfur and copper oxichloride on the post-reproductive period of A. gossypii, an increase of 4.5 times relative to the control and mancozeb taking place. Fecundity was influenced by the tested fungicides, an increase of 1.25 times in the total production of nymphs being found. The total effect of the fungicides from treated second-instar larvae of C. externa were established according to the classes of toxicity of IOBC, where sulphur proved harmless (class 1) via contact or ingestion. Mancozeb and copper oxichloride by ingestion were harmless and slightly harmful (class 2) when applied via contact.