Plantas espontâneas favorecem crisopídeos em plantio de pimenta malagueta

• Ano de defesa: 2014
• Autor(a) principal: Diaz, Natália Salgado
• Orientador(a): Venzon, Madelaine
• Banca de defesa: Souza, Brígida de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Entomologia
• Departamento: Ciência entomológica; Tecnologia entomológica
• País: BR
• Palavras-chave em Português: Pimenta - Cultivo; Pimenta - Controle de pragas; Crisopídeos; Plantas espontâneas
• Palavras-chave em Inglês: Pepper - Growing; Pepper - Pest control; lacewings; weeds
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOSSANIDADE::ENTOMOLOGIA AGRICOLA
• Link de acesso: http://locus.ufv.br/handle/123456789/3985

Habitat diversification in agroecosystems by mantaining non-crop plants is a strategy which allows the increase of beneficial arthropods since it makes the environment more suitable for natural enemies, due to the availability of food resources, oviposition sites and refuge areas. Chili pepper Capsicum frutescens is a very important crop in Brasil, because of its profitability and social value. However, this crop needs phytosanitary stand and the growers use inadequate practices in attempt to control pests. Among the several beneficial arthropods, lacewings are highlighted by their natural occurrence in various agroecosystems and by their predatory ability. From this perspective, I carried out assessments in areas of chili pepper cultivation to determine: i) the influence of noncrop plants integrated to the field in the abundance of lacewings and of aphids compared to chili pepper crops without non-crop plants, ii) the identification of non-crop plants, present in the crop, associated to lacewings (food source, oviposition and/or refuge site) and to the absence or presence of aphids, and iii) intraguild predation in eggs of C. externa in the presence and in the absence of non-crop plants. Posteriorly, in chapter 2, I studied in laboratory the role of non-crop plant flowers of common occurrence in chili pepper crops (Bidens pilosa, Ageratum conyzoides and Sonchus oleraceus) in the survivor, development, fecundity and fertility of C. externa and Ceraeochrysa cubana. According to the results found in field, the abundance of lacewings in chili pepper crop areas was favoured by the presence of non-crop plants and there was no significant difference in the presence of aphids on chili pepper plants in the areas with or without non crop vegetation. Emilia sp. (average = 1 egg/plant) and Pennisetum sp. (average = 0.54 egg/plant) were the species with the greatest presence of lacewing eggs. In Pennisetum sp., Conyza bonariensis, Marsypianthes chamaedrys, Solanum lycocarpum, and Solanum americanum it was found the greatest presence of adults with average of 1.21, 1, 0.90, 0.85 and 0.83 adults/plant, respectively. Six out of 16 non-crop plants identified in chili pepper crops had aphids on them. Intraguild predation on eggs of C. externa was higher in the areas of chili pepper crops without non-crop plants (average = 2.91 predated eggs/card/plant) compared to the chili pepper crop areas with non-crop plants (average = 2.19 eggs/card/plant). In the laboratory assessments, both C. externa and C. cubana larvae survived for a longer time in the diets of A. conyzoides and B. pilosa with flowers compared to the remaining diets in which I offered non-crop plants without flowers. Larvae development was significantly affected by the offered diets, eight C. cubana larvae pupated in the diet of B. pilosa and two C. externa larvae pupated in the diet of S. oleraceus, the higher number of pupae being formed in the diets with flowers for each lacewing species. The diet with A. kuehniella eggs was the only treatment where more than 70% of the larvae survived, pupated and emerged as adults. The average survivorship of adults in all diets with non-crop plants was five days, with no oviposition. In the diet with yeast and honey, survivorship was higher than 60 days for both lacewing species tested, with total oviposition of 775.35 (±207.8) and 1108.12 (±106.8) eggs/female for C. externa and C. cubana, respectively. Maintaining non-crop vegetation in chili pepper crop areas favours the presence of lacewings and decreases the intraguild predation. The use of plant flowers as food for larvae of C. externa and C. cubana favours their survivorship and may be useful as complementary food in the diet of these predators. Therefore, maintaining non-crop plants in crop fields may improve natural enemy survivorhip e development.