Da cozinha para o campo: potencial de óleos essenciais de condimentos para o controle de lepidópteros e a seletividade sobre o seu predador

• Autor(a) principal: Ribeiro, Rafael Coelho
• Data de Publicação: 2014
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1243
• topic: Lepidoptera - Controle biológico; Controle alternativo; Proteção de plantas; Óleos essenciais; Manejo integrado de pragas; Lepidoptera - Biological Control; Alternative control; Protection of plants; Essential oils; Integrated pest management; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA

Anticarsia gemmatalis Hubner and Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), polyphagous insects that damage plants of economic importance in Brazil and are controlled by a wide variety of chemical insecticides. The aim of this study was to verify the effectiveness of alternative control on eggs, immatures, pupae and adults of A. gemmatalis and S. frugiperda, and lethal effect on the stink bug predator Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae). The experiments were carried out in the Laboratory of Biological Control of Insects (LBCI) and greenhouse of Department of Plant Science of the Federal University of Viçosa (UFV) in Viçosa, Minas Gerais. Individuals of A. gemmatalis, S. frugiperda and adult the predator, were obtained from the mass rearing of LCBI of UFV. Eggs, larvae (third instar) and pupae of S. frugiperda and A. gemmatalis were exposed to concentrations to 1, 5, 10, 15 and 20% (v/v) essential oils and commercial products to obtain the values LC50 and LC90 needed for indices of relative toxicity (TXR50) and relative tolerance (TLR50). Acute toxicity (72 hours) of nymphs and adults (males and females) of the predator P. nigrispinus were exposed on the same treatments (essential oils and commercial products), under the same conditions (contact and topical application) described above for pest species, were measured and used the indices of TXR90, TLR90 and relative susceptibility (SLR90) between predator and pest species. Soybean Glycine max (L.) (Fabaceae) plants were treated, and the leaf discs were immersed in the LC25 treatments (obtained in toxicity test) to evaluate the repellency of egg laying and deterrence food for caterpillars of A. gemmatalis respectively. The essential oils of thyme and mint were more toxic to eggs of S. frugiperda, garlic oil and neem emulsible were toxic for eggs of both species. The higher control efficiency was observed with the essential oils of garlic, cinnamon, clove and oregano with contaminated food in third instar larvae of A. gemmatalis (velvetbean moth) and S. frugiperda. (fall armyworm). Most of the essential oils had a similar mortality in pupae of lepidopterans evaluated. The essential oils of garlic, oregano and emulsible neem were more efficient for the velvetbean moth and fall armyworm in the methods of topical and contact exposure with lower relative toxicity values (TXR90) compared to synthetic chemical. The chemical insecticide deltamethrin and oils of thyme, ginger and neem had greater danger to the males and nymphs of the stink bug. Sublethal concentrations (CL25) essential oils of cinnamon, clove, ginger, mint and thyme exhibited high repellency of egg laying (ODI > 80%) of A. gemmatalis. The effects of moderate feed deterrence (ADI > 50%) of the velvetbean moth were attributed to essential oils of garlic, cinnamon, mint and thyme. Thus, the essential oil of garlic was the most effective against the pest species A. gemmatalis and S. frugiperda and highly selective for the predator; at sublethal concentrations reduce feeding caterpillars and egg laying of females of A. gemmatalis and therefore has potential for use in Integrated Pest Management and Ecological.