Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Publication year range
1.
Environ Pollut ; 255(Pt 1): 113153, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31520906

ABSTRACT

Plant essential oils are regarded as interesting alternative tools to be integrated into the management of pest insects. However, as they generally consist of mixtures of numerous molecules, the physiological basis for their action is unresolved. Here, we evaluated the effects of essential oil of the Neotropical plant Siparuna guianensis Aubl., commonly known as Negramina, against an important pest insect: the green peach aphid Myzus persicae (Sulzer), and also in two non-target natural enemies: the ladybeetle predators Coleomegilla maculata (DeGeer) and Eriopis connexa (Germar). In addition, we conducted a computational docking analysis for predicting the physical interactions between the two Negramina essential oil major constituents: ß-myrcene and 2-undocanone, and the transient receptor potential (TRP) channels as potential binding receptors in the aphid and ladybeetles. As the most important results, Negramina essential oil caused mortality in M. persicae aphids with an LC95 = 1.08 mg/cm2, and also significantly repelled the aphids at concentrations as low as 0.14 mg/cm2. Our computational docking analysis reinforced such selectivity actions as the Negramina essential oil major compounds (i.e., ß-myrcene and 2-undocanone) bound to the TRP channels of M. persicae but not to ladybeetle-related TRP channels. Interestingly, the exposure to the Negramina essential oil did not affect the predatory abilities of C. maculata but increased the abilities of E. connexa to prey upon M. persicae. Collectively, our findings provided a physiological basis for the insecticidal and selectivity potential of Negramina essential oil, reinforcing its potential as a tool to be used in integrated pest control programs.


Subject(s)
Aphids/drug effects , Coleoptera/drug effects , Insect Repellents/pharmacology , Laurales/chemistry , Oils, Volatile/pharmacology , Plant Oils/pharmacology , Acyclic Monoterpenes/analysis , Animals , Oils, Volatile/chemistry , Plant Oils/chemistry
2.
PLoS One ; 10(2): e0116765, 2015.
Article in English | MEDLINE | ID: mdl-25646797

ABSTRACT

This study investigated the toxic effects of essential oils isolated from Siparuna guianensis against Aedes aegypti, Culex quinquefasciatus (eggs, larvae, pupae, and adult) and Aedes albopictus (C6/36) cells. The oviposition-deterring activity, egg viability, and repellence activity in the presence of different essential oils concentrations were determined. The essential oils showed high toxicity to all developmental stages of A. aegypti and C. quinquefasciatus. Furthermore, the oils also showed high repellent activity towards the adult stage of mosquitoes (0.025 to 0.550 µg/cm2 skin conferred 100% repellence up to 120 min) and in contact with cultured insect cells (C6/36) induced death possibly by necrosis. The results presented in this work show the potential of S. guianensis essential oils for the development of an alternative and effective method for the natural control of mosquitoes in homes and urban areas.


Subject(s)
Aedes/drug effects , Culex/drug effects , Insect Repellents/toxicity , Insecticides , Magnoliopsida/chemistry , Oils, Volatile/toxicity , Aedes/physiology , Animals , Cell Line , Culex/physiology , Fruit/chemistry , Insect Repellents/isolation & purification , Insecticides/isolation & purification , Larva/drug effects , Mosquito Control , Oils, Volatile/isolation & purification , Oviposition/drug effects , Ovum/drug effects , Ovum/physiology , Plant Leaves/chemistry , Plant Stems/chemistry
3.
Biosci. j. (Online) ; 27(4): 609-618, july./aug. 2011. tab, graf
Article in Portuguese | LILACS | ID: biblio-911847

ABSTRACT

As análises realizadas por cromatografia gasosa acoplada à espectrometria de massas CG/EM apresentou o citronelal como o principal fitoconstituinte dos óleos essenciais de Corymbia citriodora Hill & Johnson, e Cymbopogon nardus (L.), com 61,78 e 36,53%, respectivamente. A toxicidade dos óleos essenciais e do citronelal foi verificada para Sitophilus zeamais por meio das estimativas das curvas de concentrações resposta e tempos de exposição letais para 50 e 95% dos insetos (CL50, CL95, TL50 e TL95). A toxicidade do citronelal foi maior para S. zeamais, com CL50 e CL95 de 0,340 e 0,820µL/cm2 e TL50 e TL95 de 11,89 e 59,50h, respectivamente. A repelência de S. zeamais foi maior para os óleos essenciais de C. nardus e C. citriodora nas concentrações de 0,660; 0,881; 1,101 e 1,321µL/cm2 com 86,6 a 98,8%. O número de insetos emergidos dos grãos pulverizados com os óleos essenciais foi maior para o citronelal nas concentrações de 0,330; 0,440; 0,550, e 0,660µL/cm2 . A redução da massa de grãos foi menor para aqueles grãos tratados com C. citriodora e C. nardus. Óleos essenciais de C. citriodora e C. nardus podem proteger produtos armazenados pelo dano causado por S. zeamais.


Analysis of GC / MS showed citronellal as the main phytochemicals of the essential oils of Corymbia citriodora and Cymbopogon nardus, with 61.78% and 36.53%, respectively. The toxicity of essential oils and citronellal was verified for maize weevils, through the estimates of the concentration response curves and lethal exposure times, for 50% and 95% of the adults insect (LC50, LC95, LT50 and TL95). The toxicity of citronellal was higher for Sitophilus zeamais, with LC50 and LC95 of 0.340 at 0.820 µL/cm2, TL50 and TL95 of 11.89 and 59.50h, respectively. The repellency of S. zeamais was higher for the essential oils of C. nardus and C. citriodora, at concentrations of 1.321, 1.101, 0.881 and 0.660 µL/cm2, ranging from 86.6 to 98.8%. The number of insects emerged from grain sprayed with essential oils was lower for the citronellal, at concentrations of 0.330, 0.440, 0.550, and 0.660 µL/cm2. The reduction in grain weight was lower for those grains, treated with C. citriodora and C. nardus. Essential oils of E. citriodora and C. nardus can protect stored products from damage caused by S. zeamais.


Subject(s)
Cymbopogon , Edible Grain , Eucalyptus , Oils, Volatile , Oils, Volatile/toxicity , Weevils
4.
Acta amaz ; 28(1)1998.
Article in Portuguese | LILACS-Express | LILACS, VETINDEX | ID: biblio-1454636

ABSTRACT

This experiment was carried out at the Experimental Station of the Universidade do Tocantins in Formoso do Araguaia-TO, to study the population dinamics of soybean pests and their natural enemies. The weekly surveys were made using the plant-shaking method, in three cultivars of the medium cycle, during the period from July to October 1995, installed in a randomized block design, with four blocks. The majority of species collected ocurred in low numbers, and from the stink bug complex, only ocurred the species Piezodorus guildinii, (Heteroptera, Pentatomidae), with population peaks in the stage of grain filling. The defoliator catterpilars were found Anticarsia gemmatalis (Lepidoptera, Noctuidae), Hedylepta indicata (Lepidoptera, Pyralidae) and Chrysodeixis íncludens (Lepidoptera, Noctuidae), in decrease order of the abundance. Cerotoma sp., was the most abundant defoliator beetle found in the extension of the culture development cycle, with populations peaks closely the reprodutive stage. Among the natural enemies collected, Cicloneda sanguinea (Coleoptera, Coccinellidae); Geocoris sp. (Heteroptera, Lygaeidae) and Lebia sp. (Coleoptera, Carabidae) were the most abundants.


Neste estudo, desenvolvido na entressafra do arroz (Julho-Outubro) de 1995, no Projeto Rio Formoso, município de Formoso do Araguaia - TO, com o objetivo de verificar o comportamento da população das pragas e seus inimigos naturais em soja, foram realizados levantamentos semanais com o método do pano de batida, em três cultivares de soja de ciclo médio: EMGOPA 308, DOKO RC e EMBRAPA 31 (BR 81). Entre os percevejos fitófagos somente foi constatada a ocorrência de Piezodorus guildinii, com picos populacionais no período de enchimento de grãos, porém não atingindo o nível de controle. As lagartas desfolhadoras encontradas foram Anticarsia gemmatalis, Hedylepta indicata e Chrysodeixis íncludens, em ordem decrescente de abundância. Dos coleópteros desfolhadores, a espécie encontrada em maior abundância foi Cerotoma sp. com picos populacionais próximos ao período reprodutivo, diferindo significativamente entre as cultivares. Dentre os inimigos naturais, foi verificada a ocorrência, em maior abundância de Cycloneda sanguínea (Coleoptera, Coccinellidae), Geocoris sp. (Heteroptera, Lygaeidae) e Lebia sp. (Coleoptera, Carabidae).

SELECTION OF CITATIONS
SEARCH DETAIL
...