Effect of neem extract on the cotton aphid
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Data
2004-11-01
Autores
Santos, Terezinha Monteiro dos
Costa, Nivânia Pereira
Torres, Adalci Leite [UNESP]
Boiça Júnior, Arlindo Leal [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)
Resumo
O pulgão Aphis gossypii Glover (Hemiptera: Aphididae), praga prejudicial à cultura do algodoeiro, causa danos diretos, reduzindo o vigor da planta, e indiretos, ao secretar substância doce e transmitir viroses. em virtude da resistência desse afídeo aos inseticidas, técnicas alternativas ao controle químico, como o uso de inseticidas naturais, têm sido pesquisadas. O objetivo deste trabalho foi avaliar os efeitos de extratos aquosos de pó de amêndoas de nim (Azadirachta indica A. Juss) sobre o desenvolvimento, sobrevivência e fecundidade de A. gossypii. Os tratamentos consistiram de pó de amêndoas de nim nas concentrações de 23,8, 122,0, 410,0 e 1.410,0 mg/100 mL de água. Os porcentuais de mortalidade durante o período ninfal para os pulgões mantidos sobre discos foliares de algodoeiro imersos nas duas maiores concentrações, foram, respectivamente, 60,0% e 100,0%. Com exceção da maior concentração (1.410,0 mg/100 mL), as demais não prolongaram as fases de desenvolvimento dos pulgões. A taxa líquida de reprodução foi de 35,0 ninfas/fêmea na testemunha e de 0,0 ninfa/fêmea no grupo dos pulgões expostos à concentração de 1.400 mg/100 mL, desde o nascimento. O extrato aquoso das sementes de nim é uma alternativa eficiente para o controle de A. gossypii, causando mortalidade de ninfas e reduzindo os períodos de sobrevivência e fecundidade.
The aphid Aphis gossypii Glover (Hemiptera: Aphididae), a harmful pest on cotton, causes direct damage, reducing plant vigor, and indirect damage by honeydew secretion and transmission of several viruses. Due to the problem of pesticide resistance, alternative techniques for chemical control, such as the use of natural insecticides, have been object of research. The effects of aqueous extracts of neem (Azadirachta indica A. Juss) seed powder on the development, survival and fecundity of A. gossypii were evaluated. Treatments consisted of neem seed powder in the concentrations of 23.8, 122.0, 410.0 and 1,410.0 mg/100 mL of distilled water. Mortality rate during the nymphal development for aphids maintained on cotton leaf discs treated with the two highest concentrations were, respectively, 60.0% and 100.0%. With the exception of the highest concentration (1,410.0 mg/100 mL), neem concentrations did not extend the aphids' development period. The net reproductive rate (R0) was of 35.0 nymphs/female for control aphids and of 0.0 nymph/female when the group of females was exposed to neem seed powder at 1,410.0 mg/100 mL since birth. The aqueous extract of neem seeds is efficient against the aphid A. gossypii, causing nymph mortality and reducing their survival period and fecundity.
The aphid Aphis gossypii Glover (Hemiptera: Aphididae), a harmful pest on cotton, causes direct damage, reducing plant vigor, and indirect damage by honeydew secretion and transmission of several viruses. Due to the problem of pesticide resistance, alternative techniques for chemical control, such as the use of natural insecticides, have been object of research. The effects of aqueous extracts of neem (Azadirachta indica A. Juss) seed powder on the development, survival and fecundity of A. gossypii were evaluated. Treatments consisted of neem seed powder in the concentrations of 23.8, 122.0, 410.0 and 1,410.0 mg/100 mL of distilled water. Mortality rate during the nymphal development for aphids maintained on cotton leaf discs treated with the two highest concentrations were, respectively, 60.0% and 100.0%. With the exception of the highest concentration (1,410.0 mg/100 mL), neem concentrations did not extend the aphids' development period. The net reproductive rate (R0) was of 35.0 nymphs/female for control aphids and of 0.0 nymph/female when the group of females was exposed to neem seed powder at 1,410.0 mg/100 mL since birth. The aqueous extract of neem seeds is efficient against the aphid A. gossypii, causing nymph mortality and reducing their survival period and fecundity.
Descrição
Palavras-chave
Insecta, Aphis gossypii, Azadirachta indica, Gossypium hirsutum, extrato aquoso, Insecta, Aphis gossypii, Azadirachta indica, Gossypium hirsutum, aqueous extract
Como citar
Pesquisa Agropecuária Brasileira. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Informação TecnológicaPesquisa Agropecuária Brasileira, v. 39, n. 11, p. 1071-1076, 2004.