Bioatividade de inseticidas botânicos sobre Ascia monuste orseis (Lepidoptera: Pieridae)

• Autor(a) principal: Biermann, Ana Cristina Sapper
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Manancial - Repositório Digital da UFSM
• Texto Completo: http://repositorio.ufsm.br/handle/1/5010
• topic: Plantas inseticidas; Azadirachta indica; Nicotiana tabacum; Melia azedarach; Insecticidal plants; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA

Given the great importance of Ascia monuste orseis as insect-pest of Brassicaceae, this work was carried out to evaluate, under laboratory conditions, the action of botanical insecticides on larvae and egg masses, as well as the food consumption of larvae and test, in field conditions, the efficiency of control, of botanical insecticides which showed better results in laboratory tests, on larvae of A. monuste orseis in kale plants (Brassica oleracea L. var. acephala DC). In laboratory tests were evaluated, at a temperature of 25 ± 2ºC, relative humidity of 60 ± 10% and photophase of 14 hours, the effects of aqueous extracts of 10% w/v of tobacco powder (Nicotiana tabacum L.), of leaves of Melia azedarach L., Eucalyptus tereticornis Sm., Cedrella fissilis Vell. and Trichilia claussenii C. DC., of leaves and twigs of Ateleia glazioveana Baill and Ruta graveolens L., as well as DalNeem®, commercial product based on ripe fruits of neem (Azadirachta indica A. Juss) at 1, 5 and 10% v/v. After being offered discs of kale leaves treated with different treatments to larvae of three days of age, the mortality, the viability of the larval stage and food consumption were evaluated. Also the action of the extracts on egg masses was tested. From topical applications of the extracts on larvae of three days the effect of contact was evaluated through observation of the viability and duration of the larval stage, pupal viability and weight of pupae, and the number of adults with defect. Finally, in experiment conducted in the field, the efficiency of control of products that had better performance on tests in laboratory (tobacco powder, DalNeem to 1% and M. azedarach), compared with the standard treatment, product-based deltamethrin (Decis 25 EC) was estimated. It was found that, in laboratory, the tobacco powder was the treatment that best showed ovicidal activity; after ingestion of the extracts tested, the tobacco powder, followed by DalNeem were better in relation to mortality caused to the larvae; DalNeem, tobacco powder and M. azedarach affected their viability; the contact of DalNeem and tobacco powder caused total mortality of larvae and extracts of M. azedarach resulted in little more than half of viable pupae, presenting a tendency to reduce the weight of pupae and causing malformation in the wings of all adults emerged; both by ingestion and contact action, the extracts tested practically did not change the duration of the larval stage and all the extracts caused fagodeterrente effect on A. monuste orseis. To control A. monuste orseis in Brassicaceae crop, it is recommended the commercial product DalNeem to 1%, respecting the product specifications, since the tobacco powder, in the field, causes dark pigmentation on kale plants.