Navegando por Assunto "Inseticidas vegetais"

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Análise comparativa do potencial inseticida dos óleos essenciais das folhas e frutos de Melaleuca leucadendra sobre a traça das crucíferas (Plutella xylostella)
(2019-06-28) Santos, Rodrigo Bastos dos; Camara, Cláudio Augusto Gomes da; http://lattes.cnpq.br/5615678215435460; http://lattes.cnpq.br/3667225401473912
The objective of this work is to investigate the insecticidal potential of the essential oils of the different parts of Melaleuca leucadendra, on the cruciferous moth, Plutella xylostella, contributing to the studies aimed at botanical insecticides. To this end, we analyzed comparatively the insecticidal activity of the leaf and fruit oils of M. leucadendra on P. xylostella by means of the larvicide toxicity bioassays and embryocid toxicity, also comparing its results with the insecticide Azamax® Commercial. The OEs obtained for leaves and fruits of M. leucadendra, presented yield of 0.28% ± 0.05 and 0.18% ± 0.03 respectively, being all in acceptable standards for plants producing essential oils. As the majority constituent of these oils, sesquiterpene (E)-nerolidol in concentrations above 90% was characterized in both parts. The results obtained through the larvicide toxicity Bioassay showed a lethal mean concentration of 0.15 mg/mL and 0.17 mg/mL for the oils of the fruits and leaves of M. leucadendra, respectively, but not statistically different. For the experiments carried out on the embryonic phase of P. xylostella, again there was no statistical difference, showing LC50 of 0.23 mg/mL and 0.28 mg/mL for leaf and fruit oils, respectively. Both essential oils, as well as the majority constituent, presented higher toxicity on the cruciferous moth than the commercial insecticide Azamax® (LC50 = 2,75 mg/mL and LC50 = 2,57 mg/mL on the larvae and eggs, respectively), showing promising in the control of the Plutella xylostella.
Atividade insetistática de pós de origem vegetal sobre Sitophilus zeamais Motschulsky (1855) em milho armazenado
(2020) Magalhães, Aline Pereira de; Oliveira, Carlos Romero Ferreira de; http://lattes.cnpq.br/2515051171734004; http://lattes.cnpq.br/7331352853811552
Corn is one of the main agricultural crops in Brazil, as it is used to several by-products, fact that contributes to its comercial value and the economic movement in the country. It is an energetic aliment which has high nutricional value and is easy accessible, been part of human and animal diet. However, there are considerable damages due the attack of pest insects, mainly caused by Sitophilus zeamais Motschulsky, 1855 (Coleoptera: Curculionidae), which has great agricultural importance, for attacking in the field and in the warehouses, in addition to destroying the healthy grain, taking the chance to ovoposit, being considered, therefore, internal primary pest. This pest control is carried out with synthetic insecticides, however, its use is harmful to the environment, besides human and animal heath. The use of vegetable origin powders has been shown to be effective against stored grain pests, moreover, it is easy to obtain and use, also being within the range of the small farmer. The aim of this paper was to evaluate the toxicity and repellency of five powders of vegetable species on S. zeamais. Leaves of Croton pulegiodorus (Velaminho), Momordica charantia (Melão-de-São-Caetano), Azadirachta indica (Nim), Prosopis juliflora (Algaroba) e Ziziphus joazeiro (Juazeiro) were dried and ground, separately, to obtain a refined powder, subsequently applied to samples of corn kernels, in different powder amounts (0g, 1g, 2g, 3g, 4g, 5g), contained in Petri dishes (mortality assessment) and in interconnected flasks (repellency assessment). Each treatment was infested with 10 non-sexed adult insects, using six replications in a completely randomized design, at room temperature. All experiments were evaluated after a period of 72 hours. Only C. pulegiodorus caused high insect mortality (76.67% to 100%), being extremely low when in contact with other plants (0% in Z. joazeiro to 26.67% in A. indica). In addition, the mortality caused by A. indica was higher than that of the control only in the 3g amount of powder, while the other species (P. juliflora, Z. joazeiro and M. charantia) did not differ from the control and neither among themselves. It was observed that only C. pulegiodorus had a repellent action, as the other plants were considered neutral. These results demonstrate that the dry extract (powder) of velaminho (C. pulegiodorus) is a promising alternative for the management of S. zeamais in stored corn as it has biological activity on this coleopteran.
Atividade larvicida do extrato celular e de lectina extraídos de Chlorella vulgaris frente larvas em L4 de Aedes aegypti
(2020-11-11) Silva, Maria Laura da; Bezerra, Raquel Pedrosa; http://lattes.cnpq.br/1466206759539320; http://lattes.cnpq.br/0330489267196523
Dengue, chikungunya and zika are viral diseases caused by the transmitting agent Aedes aegypti. According to data from the World Health Organization (WHO), the numbers of cases of these infections are increasing, the main method of prevention being the use of chemical insecticides to combat the vector, which has provoked resistance in the populations. The search for insecticides extracted from natural sources has been an alternative, thus, microalgae appear as a new possibility because they present biodegradable and non-toxic bioactives. Therefore, this research aimed to use the cell extract and Chlorella vulgaris lectin on A. aegypti to investigate larvicidal activity and inhibition on trypsin in the fourth larval stage (L4). The biomass of C. vulgaris was grown in Bold's Basal Medium. The biomass was concentrated and resuspended in a proportion of 10% w / v in 0.1 M Tris-HCl-NaCl buffer, pH 7.5 for the preparation of the cell extract by magnetic stirring for 9h and later performed hemagglutinating activity. Lectin was purified using anionic chromatography (DEAE-Sephadex) and Superdex 75 molecular exclusion. Cell extract at concentrations of 3.13% to 100%, and lectin from 25 to 200 μg mL-1, were applied to the larvae A. aegypti L4 during the 72-hour period following WHO recommendations. The cell extract showed an LC50 value with 3 hours (LC50 = 43.50%) and 24 hours (LC50 = 10.62%). While lectin showed LC50 at 24 hours (164.2 μg mL-¹), 48 hours (125.3 μg mL-¹) and 72 hours (106.5 μg mL-1). To observe the mechanism of action of intestinal trypsin, the LC50 of the cell extract containing 260 μg ml-1 of protein was applied to the fourth stage of A. aegypti larvae. Upon reaching the fourth stage, the larvae were incubated with the microalgae cell extract for a total period of 10 hours, and every 2 hours trypsin activity was performed. It was observed that the longer the cell extract treatment time with the larvae, the greater the reduction in intestinal extract trypsin activity. There was a 34.93% reduction in activity from the initial time with 2 hours to the final time with 10 hours. Thus, the present study using the cell extract, as well as the lectin isolated from C. vulgaris, appears as a new larvicidal potential of A. aegypti.
Avaliação da toxicidade do extrato de folhas de Annona squamosa para Aedes aegypti, Nasutitermes corniger e Sitophilus zeamais
(2019-12-20) Santos, Lucas Gabriel Pita dos; Pontual, Emmanuel Viana; Almeida, Welton Aaron de; http://lattes.cnpq.br/6880632191779221; http://lattes.cnpq.br/1777060469196142; http://lattes.cnpq.br/5858954656778360
The high environmental toxicity of the compounds currently used for control of insect pests, as well as the emergence of resistant populations have stimulated the search for new agents with insecticidal activity. In this work, an extract of Annona squamosa (Annonaceae) leaves was evaluated for the presence of proteins and secondary metabolites. The effect of the extract on larvae of Aedes aegypti (vector of dengue, yellow fever, zika and chikungunya) and adults of Nasutitermes corniger (urban pest) and Sitophilus zeamais (agricultural pest) was also investigated. The chemical characterization of the extract revealed the presence of proteins, lectin (HAE = 21,3) and trypsin inhibitor (15,6 U/mg) activities, as well as secondary metabolites the classes of flavonoids (rutin), cinnamic derivatives (chlorogenic acid), saponins, anthraquinones, terpenes and steroids. The extract was in toxic to A. aegypti larvae and the concentration required to kill 50% of larvae (CL50) was 1.9% (m/v). On the other hand, the extract did not affect the survival of N. corniger soldiers and workers. S. zeamais adults showed mortality ranging from 51.2 to 63.8% regarding the control when fed with the diet containing the extract (15 to 75 mg/g), but a strong deterrent feeding effect was detected. This data revealed that the insects die from starvation and not from intoxication due to the extract intake. The treatment with the extract resulted in high mortality of Hyalella sp. at the concentration corresponding to the LC50 for A. aegypti. However, the presence of the extract interferes with the pH and the amount of dissolved O2 in the culture solution, suggesting that Hyalella sp mortality cannot be a result of a direct toxicity of the extract. In conclusion, the A. squamosa leaf extract is an interesting candidate for use in the control of A. aegypti populations and as a protection agent for stored grains against the S. zeamais attack. Additionally, the use of the extract in the environment needs caution due to the high mortality detected for Hyalella sp.
Avaliação de extratos de mamona Ricinus communis e do coité Crescentia cujete L. no controle de Aphis craccivora Koch (Hemiptera: Aphididae) em feijão caupi
(2019) Ferreira, Vandeilson Bezerra; Evangelista Júnior, Walter Santos; Nascimento, Antônio Henrique Cardoso do; http://lattes.cnpq.br/5216997634308364; http://lattes.cnpq.br/6728342264331935; http://lattes.cnpq.br/2799857312943263
Controlling agricultural pests is a practice that has been undergoing innovations constantly. The use of plant extracts appears as an alternative of pest control and is recommended mainly in family agriculture, and in fields of production mainly in organic agriculture, being a low cost product, easy to obtain and high effectiveness in pest control. The extracts of the plants of MamoneiraRicinuscommunisand CoitéCrescentiacujeteL. are promising in the natural control of pests, as they have toxic substances such as ricin, phenolic compounds and flavonoids, respectively. The objective of this work was to evaluate the effect of the extracts of these plants on the black aphid mortality of the common bean Aphis craccivora(Hemiptera: Aphididae). Mamona and Coité extracts caused a high mortality on black bean aphid with rates of 74.69% and 70.23%, respectively. Comparing the black aphid mortality in the different extracts per day after the application of the extracts, it was verified that the Mamona extract had a higher mortality rate (84.86%) on the first day of evaluation and the second day had a coefficient of 81.3%. However, there was no difference between the plant extracts during the five days of evaluation and they differed from the control throughout the evaluation period, which reinforces the efficiency of the use of these extracts in the control of this pest, as well as the necessity of use of control methods. It is concluded that the plant extracts of Mamona and Coité are efficient in controlling the mortality of black aphid A. craccivoraand contribute to the management of this pest in family agriculture, organic and agroecologicalcrops.
Composição química, atividade inseticida e potencial antioxidante dos óleos essenciais das folhas e flores de Plumeria pudica Jacq
(2022-09-30) Arcelino, Ariadna Isis Oliveira de; Moraes, Marcílio Martins de; http://lattes.cnpq.br/0321382004671685; http://lattes.cnpq.br/0321382004671685
Agricultural producers usually suffer from the attack of pest insects that cause great damage to plantations, among these insects is Plutella xylostella, popularly known as cruciferous moth, as it usually attacks Brassicas plantations, this pest has already caused a global damage of about of US$ 4 billion. Currently, the control of this pest is carried out with commercial insecticides, but the excessive use of these products tends to cause greater resistance of the pest, in addition to contaminating soil, rural workers and mammals. With that, seeing being studied the use of natural products such as extract and essential oil of plants, as an alternative for the control of these agricultural pests, since these materials have in their chemical composition secondary metabolites with high toxicity to insect pests without causing damage to the environment, workers and consumers. The present work analyzed the chemical composition of the essential oil of the leaves and flowers of Plumeria pudica in order to evaluate its chemical composition and insecticidal and antioxidant properties. The analysis by gas chromatography coupled with mass spectrometry (GC-MS) revealed the presence of 8 and 13 compounds in the essential oil of leaves and flowers, respectively. The major compounds identified were (2E)-hexenal (40.67%) and lauric acid (39.97%) for leaves and flowers, respectively. The toxicity bioassay was carried out through residual contact and direct contact with the oil of P. pudica flowers with concentrations of 10μL/mL and 15μL/mL on P. xylostella, for the test using residual contact the oil did not show toxicity, on the other hand, using direct contact, the concentration of 10μL/mL showed a toxicity of 92% and 15μL/mL of 93.10%. In the antioxidant tests it was found that the two oils were active both in the ABTS and DPPH test. In the antioxidant tests, it was found that the oils from the leaves and flowers were active both in the ABTS test and with DPPH. For the acetylcholinesterase (AChE) inhibition test, the oils from the leaves and flowers of P. pudica were used, both oils showed inhibition, and the flower oil showed the closest inhibition to the positive control with an IC50 of 9 .94 mg/ml. The cytotoxicity assay against Artemia salina was also performed with the oils of leaves and flowers with concentrations between 10-100μg/mL and both showed no toxicity.
Efeito comparativo de inseticidas naturais e sintético no aparelho digestivo, gônadas e nutrição do bicudo-do-algodoeiro Anthonomus grandis Boheman (Coleoptera: Curculionidae)
(2021-12-09) Ferreira, Maria Clara da Nóbrega; Cruz, Glaucilane dos Santos; Teixeira, Valéria Wanderley; http://lattes.cnpq.br/4292195468804301; http://lattes.cnpq.br/3795270436231657; http://lattes.cnpq.br/6415809873371718
Efeito de extratos aquosos de plantas sobre o ácaro verde da mandioca Mononychellus tanajoa (Bondar) (Acari: Tetranychídae)
(2001) Gonçalves, Manoel Eneas de Carvalho; Pereira, Francisco Fernandes; Magno, Marcia Valois; Oliveira, José Vargas de
Algumas substâncias de origem vegetal surgem no cenário agrícola como uma alternativa bastante promissora, eficiente e de fácil aquisição para o controle de pragas de culturas economicamente importantes, no sentido de minimizar os efeitos colaterais do uso de inseticidas químicos. No presente trabalho, avaliou-se o efeito dos extratos aquosos de cravo-da-índia (Sizygium aromaticum), cominho (Cuminum cymínum), pimenta-do-reino (Piper nigrum), amêndoas de sementes de nim (Azadirachta indica) e de folhas de canela (Cinnamomum zeylanicum) na mortalidade do ácaro verde de mandioca Mononychellus tanajoa, todos na concentração de 5 e 10% (p/v). O material vegetal moído foi misturado com água destilada em recipientes de vidro, deixado em repouso por 24 horas para extração das substâncias secundárias, e posteriormente coado em tecido fino. Utilizou-se como parcela uma lâmina de microscopia, na qual foi colada uma fita adesiva dupla face de 2 cm² como substrato para fixação dos ácaros. Em cada lâmina foram presas pelo dorso com o auxílio de um pincel de pêlo fino, 15 fêmeas adultas de M. tanajoa. O experimento constou de 10 tratamentos e duas repetições e foi conduzido no delineamento experimental inteiramente casualizado. As lâminas foram mergulhadas nos extratos por cinco segundos, fazendo-se uma leve agitação e posteriormente colocadas em posição vertical para escoamento do excesso de extrato retido. Na testemunha, utilizou-se apenas água destilada. A mortalidade foi determinada após 24h, sendo considerados mortos, os ácaros que não se moviam com um simples toque de pincel. Os extratos em nim 10%, cravo-da-índia 5 e 10% causaram 100% de mortalidade, diferindo de pimenta-do-reino 5 e 10%, cominho 5% e canela 5%.
Efeito do óleo de pequi (Caryocar brasiliense Camb) obtido na feira livre de Princesa Isabel – PB, sobre Callosobruchus maculatus em feijão armazenado
(2018) Lima, Edna Alves de; Silva, Renato Augusto da; http://lattes.cnpq.br/5111987334920733; http://lattes.cnpq.br/3607195370784211
The Cowpea bean, Vigna unguiculata (Fabaceae), has an extraordinary role in feeding the population of the north and northeast regions of the country. However this culture is still detrimental to the loss of 10% of production due to the attack of insect-pests and use of synthetic chemical pesticides. In the present work the effect of the oil of Pequi (Caryocar brasiliense Camb.) As natural defensive, was studied on the dry rot (Callosobruchus maculatus) in Beanscowpea both acquired in the city of Princess Isabelle, Sertão of Paraíba. The methodology is very simple and can be reproduced in a domestic environment, because there is no need for the use of toxic substances, the oil of pequi used in cooking and alternative medicine. For the experiment it was used only of plastic containers, account drops and domestic balance, all low cost and commercially accessible. Concentration of 0.0 mg to 167.0 mg of oil per 20g of beans were analyzed and as a result was estimated the average lethal concentration (LC50) = 98.24 by means of linear regression. The good results presented here revealed that Pequi oil can be an economically viable and affordable alternative to the management of the rot in stored beancowpea beans.
Extratos da algarobeira como alternativa de controle do pulgão preto do feijoeiro Aphis craccivora
(2018) Vieira, Domingos Sávio Marques de Menezes; Evangelista Júnior, Walter Santos; http://lattes.cnpq.br/6728342264331935; http://lattes.cnpq.br/7384301568742851
The extracts of plants are recommended in family agriculture, characterized by small and medium producers, mainly related to the organic production. One way of obtaining compounds or plant substances is through the isolation of active principles or specific chemical group with insecticidal action, among them the alkaloids. The Prosopis juliflora algarobeira presents several substances with insecticidal and antifungal properties. Thus, the objective of this research was to evaluate the insecticidal effect of the alcoholic and aqueous extracts of algarobeira leaves on the black aphid of the common bean Aphis craccivora (Hemiptera: Aphididae). The experiment was carried out in the UAST experimental area. Statistical analyzes were performed by analysis of variance, using the Tukey test with significance level at 5% probability, using the Sisvar 5.6 (2011) computational package. It was observed that the dosages of FAT (100, 50, 25 and 10 mL / L) did not present significant toxicity, where there was no mortality of A. craccivora. Using the aqueous extract of the algaroba, a mortality ranging from 5.94% and 30.12% of the black aphid was observed. It is concluded that the algaroba extract presented low efficiency on the mortality of A. craccivora.
Folhas de Syzygium malaccense Linnaeus (Myrtaceae): caracterização química e efeitos sobre Plutella xylostella Linnaeus (Lepidoptera: Plutellidae)
(2019-06-28) Santos Neto, Erasmo Guilherme dos; Pontual, Emmanuel Viana; Vila Nova, Isabella Coimbra; http://lattes.cnpq.br/8445185379848462; http://lattes.cnpq.br/1777060469196142; http://lattes.cnpq.br/6695192736858780
Plutella xylostella (Plutellidae) is an important pest that attacks Brassicas cultures worldwide. Syzygium malaccense (Myrtaceae), or jambeiro, is used in popular medicine and its fruits are consumed as foodstuff. Lectins (carbohydrate-binding proteins) and trypsin inhibitors can be insecticidal agents. This work characterized the aqueous extract of S. malaccense for the presence of secondary metabolites, lectins and trypsin inhibitors, as well as for insidicidal activity against P. xylostella. Analysis by thin layer chromatography revealed the presence of polyphenols (hydrolyzed tannins), flavonoids, steroids, saponins and reducing sugars in the leaf extract, which also contained lectins (hemagglutinating activity of 64) and trypsin inhibitor. was inhibited by monosaccharides glucose and Nacetylglucosamine and neutralized by the glycoproteins fetuin and ovalbumin. The leaf extract exerted a detergent feed effect and induced mortality of P. xylostella caterpillars. The mortality rate of 80 ± 15% for the 1% leaf extract was recorded. The oviposition detergent effect was also determined for the leaf extract, since the presence of about 37 eggs was detected in the treated discs against 80 eggs recorded in the control. Exhaustive heating of the leaf extract altered the hemagglutinating and detergent food activities in a similar manner, suggesting that these can be attributed to the same protein. Exposure of leaf extract to environmental conditions for 192 h neutralized its food-producing effect. In conclusion, leaf extract of S. malaccense is a source of secondary metabolites, lectin and trypsin inhibitor, and constitutes an insecticidal agent against P. xylostella for causing mortality of caterpillars and altering their feeding and oviposition behaviors.
Investigação do efeito do extrato de flores de Moringa oleifera Lamarck (Moringaceae) na sobrevivência e atividade de enzimas digestivas de larvas de Plutella xylostella Linnaeus (Lepidoptera: Plutellidae)
(2019-02-01) Ferreira, Camila Azevedo; Pontual, Emmanuel Viana; Almeida, Welton Aaron de; http://lattes.cnpq.br/6880632191779221; http://lattes.cnpq.br/1777060469196142; http://lattes.cnpq.br/1108068314774367
Plutella xylostella is a multiresistant agricultural pest that attacks brassica plantations in Brazil and worldwide. The use of natural products with insecticidal properties to control P. xylostella may be advantageous due to the higher degree of degradability and lower persistence of these compounds in the environment when compared with the effects of synthetic insecticides. Moringa oleifera Lam. (Moringaceae) is a pantropical tree that synthesizes proteins (lectins and trypsin inhibitor) whose insecticidal activity has been reported. In the present work, the M. oleifera flower extract containing trypsin inhibitor (MoFTI, M. oleifera flower trypsin inhibitor) was investigated for the presence of peptides resistant to hydrolysis by digestive proteases and effect on survival and protease activity from midgut of P. xylostella third instar larvae (L3). The flower extract showed a high molecular weight polypeptide, which was resistant to hydrolysis by larval gut proteases up to 270 min incubation, revealed by polyacrylamide gel electrophoresis. The larvae were sensitive to the treatment with the extract and the mortality curve revealed a dose dependent response following a polynomial order 2 regression with R2 = 0.99. The maximum mortality rate (60 ± 10%) of larvae was obtained for the extract at 2% (w/v). The adults who emerged from treatment with flower extract showed morphological alterations, including atrophy of the wings and inability to move. In addition, some insects were not able to abandon the cocoon after the end of the pupal phase. The total protease and trypsin-like activities from larval gut were reduced in 67.75 ± 0.64% and 65.83 ± 6.3% by the flower extract at 0.8% and 1%, respectively. Deterrent alimentary effect was not detected when the larvae were reared with cabbage discs treated with the extract at 0.5 and 1%. In conclusion, the M. oleifera flower extract is a larvicidal agent against P. xylostella by cause larval mortality and malformations in adult insects. The larvicidal effect of the flower extract may be linked to the inhibition of enzymes important for the digestive processes of P. xylostella.
Potencial de desenvolvimento do pulgão Aphis citricidus kirk em dois hospedeiros e seu controle com produtos químicos e naturais
(2001) Oliveira, José Eudes de Morais; Torres, Jorge Braz; Batista, Jacinto de Luna
Este trabalho estudou o desenvolvimento do pulgão Aphis citricidus Kirk (Homoptera: Aphididae), em acerola Malpighia glabra e laranja Citrus sp., bem como seu controle por produtos químicos e naturais. Os parâmetros de desenvolvimento e reprodutivo do pulgão, foram determinados para a elaboração da sua tabela de vida de fertilidade nas plantas de acerola e laranja. A taxa líquida de reprodução (Ro) foi de 31,5 ± 2,57 e de 15,9 ± 1,43 para acerola e laranja, respectivamente. O tempo de geração (T) e a taxa intrínseca de crescimento (rm) foram de 27,9 ± 1,24 e 0,12 ± 0,003 e, 16,9 ± 0,66 e 016 ± 0,007 para acerola e laranja, respectivamente. A logenvidade média das fêmeas foi de 44,7 ± 3,64 dias para acerola, sendo maior que 27,8 ± 2,28 dias, obtidos em laranja. Em relação ao controle, os inseticidas deltametrina 25 CE e diazinon 600 PM, apresentaram eficiência acima de 80% comparado ao óleo mineral, que proporcionou 70% de eficiência. Para os extratos vegetais estudados, aquele obtidos da folha de erva-doce, Pinpinella anisum, de eucalipto Eucalyptus citriodora e de folha de bulbo de tiririca Cyperus rotandus, foram respectivamente os mais eficazes, com eficiência variando de 35% a 60,6%. Para o enxofre, a concentração de 10g/200mL de água, foi mais eficaz que as concentrações 6 e 8g/200mL, após 24h e 48h da aplicação.