Introduction: Aedes aegypti is responsible for the transmission of the dengue and yellow fever viruses. This study evaluated the effects of extracts from Cnidosculos phyllacanthus, Ricinus communis, and Coutarea hexandra on the developmental periods of A.aegypti larvae and pupae. Crude extracts of C. phyllacanthus and C. hexandra and oil from R. communis and C. phyllacanthus were used. Methods: Bioassays of the larvicidal and pupicidal effects of these products at different concentrations and times of exposure were evaluated. The lethal and sublethal effects were determined using different concentrations in larvicidal tests. Mortality data were evaluated by Probit analysis to determine the LC 50 and LC 90 values. Results: The vegetable oils from C. phyllacanthus and R. communis demonstrated greater effi ciency for larval control with an LC 50 =0.28µl/mL and an LC 90 =1.48µl/ mL and LC 50 =0.029µl/mL and a LC 90 =0.26µl/mL, respectively. In pupal tests toxic effects for all insects were verifi ed after exposure to the products at signifi cant LC 50 and LC 90 values for 24 and 48h. The effects of sublethal concentrations of C. phyllacanthus (oil) were more effective on the insects. Conclusions: The vegetables oils from C. phyllacanthus and R. communis demonstrated greater potential from the control of different developmental periods in the life cycle of this insect.
Despite the increase in recent decades in herbicide research on the potential of native plants, current knowledge is considered to be low. Very few studies have been carried out on the chemical profile or the biological activity of the Brazilian savanna (Cerrado) species. In the study reported here, the allelopathic activity of AcOEt and MeOH extracts of leaves, stems, and roots from Ocotea pulchella Nees was evaluated. The extracts were assayed on etiolated wheat coleoptiles. The AcOEt leaf extract was the most active and this was tested on standard target species (STS). Lycopersicon esculentum and Lactuca sativa were the most sensitive species in this test. A total of eleven compounds have been isolated and characterized. Compounds 1, 2, 4, and 6 have not been identified previously from O. pulchella and ocoteol (9) is reported for the first time in the literature. Eight compounds were tested on wheat coleoptile growth, and spathulenol, benzyl salicylate, and benzyl benzoate showed the highest activities. These compounds showed inhibitory activity on L. esculentum. The values obtained correspond to the activity exhibited by the extract and these compounds may therefore be responsible for the allelopathic activity shown by O. pulchella.
Atividade repelente de extratos de Cnidoscolus phyllacanthus Mart. e Ricinus communis L. sobre o comportamento de oviposição de Aedes aegypti L. Fêmeas de Aedes aegypti põem seus ovos em qualquer lugar úmido e com acúmulo de água. Métodos alternativos com potencial de repelência à oviposição de insetos reduz a infestação contribuindo para controlar epidemias. Avaliou-se a inluência de extratos de Cnidoscolus phyllacanthus e Ricinus communis sobre o comportamento de oviposição de A. aegypti. A repelência a oviposição foi avaliada a partir das concentrações letais CL 50 e CL 90 obtidas no teste com larvas deste vetor após 24 horas de exposição. O teste de preferência para oviposição de A. aegypti foi baseado em duas situações: teste de múltipla escolha e teste sem chance de escolha. Os resultados do Índice de Atividade de Oviposição (IAO) para o teste de múltipla escolha, para ambos R. communis e C. phyllacanthus, foram negativos. A CL 90 de R. communis e C. phyllacanthus apresentaram atividade repelente de oviposição, sendo conirmado pelo IAO = -1. Diferença signiicativa entre as médias dos tratamentos foi veriicado no teste com escolha tanto para R. communis quanto para C. phyllacanthus. No teste sem chance de escolha, os mosquitos ovipositaram independente do tipo de substrato. A partir dos valores de IAO, todos os produtos apresentaram ação repelente à oviposição de A. aegypti.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.