ABSTRACT
Among several factors that impact the bean culture productivity there are pest insects, which affect the plant since seeding until postharvest, causing loss in the culture yield. The fall armyworm (Spodoptera frugiperda) stands out among the main pests of common bean (Phaseolus vulgaris). The aim of this work was to evaluate the effectiveness of insecticides of the neonicotinoid group in the control of the fall armyworm in the bean crop, comparing dinotefuran, acetamiprid, thiamethoxam and imidacloprid performance. Experimental design was composed of blocks entirely randomized, with 9 treatments and 10 replicates. Three caterpillars, at the stage of second instar, were used in each experiment, focusing on the ingestion of leaves containing the treatments. Evaluations were realized in the intervals of 1, 3, 6 and 8 days after every application, counting the number of caterpillars alive in the Petri's dish, attributing visual notes on bean leaves, according to the foliar area affected (consumed). The dinotefuran treatment with the highest dose presented superior efficiency at 80% in the first evaluation. The thiamethoxam treatment with the lowest dose, in the latest analyses, showed efficient superior at 90%. The major doses of all treatments presented efficiency higher than 80% in the last evaluations, being efficient in the S. frugiperda control.
Subject(s)
Pest Control/methods , Spodoptera , Phaseolus/parasitology , Neonicotinoids/administration & dosage , Neonicotinoids/analysisABSTRACT
El complejo de mosca blanca (Hemiptera: Aleyrodidae) incluye algunas de las principales plagas del ejote francés (Phaseolus vulgaris L.). Dentro de las cuales, Bemisia tabaci es vector del virus del mosaico dorado que afecta la calidad y rendimiento del cultivo, con pérdidas hasta del 100% y un control difícil debido a la resistencia adquirida por las plagas hacia algunos agroquímicos. El ejote francés ocupa el segundo lugar entre de los productos no tradicionales de exportación de Guatemala. Su manejo agronómico ha sido principalmente a través del control químico, el cual afecta insectos y otros organismos que no son el objetivo del control, tales como: polinizadores, insectos benéficos, humanos y fauna silvestre. Los objetivos del estudio fueron: determinar la presencia de enemigos naturales nativos de la mosca blanca e identificar las especies de mosca blanca presentes en el cultivo del ejote francés en Chimaltenango. Para el estudio se establecieron cuatro parcelas de 300 m², se realizaron muestreos semanales durante dos ciclos del cultivo. En cada parcela se muestrearon cinco sitios y en cada sitio cinco plantas. Las especies de parasitoides nativos encontrados fueron: Encarsia Formosa Gahan, Eretmocerus eremicus Rose y Zolnerowuch y Amitus fuscipennis MacGown y Nebeker, la especie más abundante fue A. fuscipennis. Los depredadores identificados fueron Chrysoperla carnea (Stephens) e Hippodamia convergens Guerin-Meneville. La especie más abundante fue H. convergens. Estas especies podrían ser herramientas valiosas para ser empleadas en programas de control biológico, producciones orgánicas o en programas de manejo integrado de plagas.
The whitefly complex (Hemiptera: Aleyrodidae) includes some of the main pests of the French green bean (Phaseolus vulgaris L.). Among which, Bemisia tabaci is a vector of the golden mosaic virus that affects the quality and yield of the crop, with losses up to 100% and difficult control due to the resistance acquired by pests towards some agrochemicals. The French green bean ranks second among the non-traditional export products of Guatemala. Its agronomic management has been mainly through chemical control, which affects insects and other organisms that are not the objective of the control, such as: pollinators, beneficial insects, humans and wildlife. The objectives of the study were: to determine the presence of natural enemies native to the whitefly and identify the species of whitefly present in the cultivation of the French bean in Chimaltenango. For the study, four 300 m² plots were established, weekly sampling was carried out during two crop cycles. Five sites were sampled on each plot and five plants on each site. The native parasitoid species found were: Encarsia Formosa Gahan, Eretmocerus eremicus Rose and Zolnerowuch and Amitus fuscipennis MacGown and Nebeker, the most abundant species was A. fuscipennis. The predators identified were Chrysoperla carnea (Stephens) and Hippodamia convergens Guerin-Meneville. The most abundant species was H. convergens. These species could be valuable tools to be used in biological control programs, organic productions or in integrated pest management programs.
Subject(s)
Animals , Phaseolus/parasitology , Hemiptera/growth & development , Pest Control, Biological/methods , Phaseolus/growth & development , Diptera , Hemiptera/parasitology , Mosaic VirusesABSTRACT
Arcelin, the antimetabolic protein from wild pulses is a known natural insecticidal molecule. Wild pulses with high arcelin content could serve as potential source to increase the levels of insect resistance in cultivated pulse crops. In this study, arcelin (Arl) gene expression was screened in seven stored product insect pest resistant wild pulse varieties using real time RT-qPCR. Arcelin gene specific real time PCR primers were synthesized from arcelin mRNA sequence of the wild pulse variety, Lablab purpureus. The results revealed different levels of arcelin gene expression in the tested varieties. Canavalia virosa registered significantly high content indicating its suitability for utilization of arcelin gene in developing stored product insect pest resistance with other cultivated pulses.
Subject(s)
Animals , Coleoptera/physiology , Canavalia/genetics , Canavalia/parasitology , Disease Resistance/genetics , Fabaceae/classification , Fabaceae/genetics , Fabaceae/parasitology , Gene Expression Regulation, Plant , Glycoproteins/genetics , Host-Parasite Interactions , Phaseolus/genetics , Phaseolus/parasitology , Plant Diseases/genetics , Plant Diseases/parasitology , Reverse Transcriptase Polymerase Chain Reaction/methods , Seeds/genetics , Seeds/parasitology , Species SpecificityABSTRACT
Visando padronizar método de criação de Tetranychus urticae Koch em Phaseolus vulgaris (var. ICA Cerinza) para alimentação do ácaro predador Phytoseiulus persimilis Athias-Henriot, foram conduzidos experimentos para identificar: a idade mais apropriada da planta para infestação com T. urticae e o momento após infestação inicial em que se deve recomeçar o ciclo de produção. Para o primeiro experimento, foram utilizados feijoeiros de quatro, cinco, seis e sete semanas de idade, infestadas com seis fêmeas de T. urticae por folíolo. Em todas as idades foi encontrado maior número de indivíduos de T. urticae no terço inferior das plantas, constituído principalmente por folhas cotiledonares. No entanto, o maior número de novos indivíduos de cada idade de T. urticae foi obtido em plantas de quatro semanas. No segundo experimento foram infestadas feijoeiros de quatro semanas de idade com 0,5 fêmea/cm² de folha. Semanalmente, foi registrado o número de estágios biológicos presentes de T. urticae. A produção máxima de T. urticae foi obtida entre a quarta e quinta semanas após a infestação, sendo esse o momento ideal para a colheita e recomeço do ciclo de produção.
A rearing technique was standardized to produce Tetranychus urticae Koch on Phaseolus vulgaris (ICA Cerinza variety) as a prey of the predatory mite Phytoseiulus persimilis Athias-Henriot. Two assays were conducted to assess the following variables: 1. the most suitable plant age for mite infestation, 2. the best time to harvest the mites and reinfest the plants. In the first experiment, four-, five-, six-, and seven-week-old plants of P. vulgaris were infested with six T. urticae per foliole. The lower plant stratum exhibited the largest number of mites regardless of plant age. However, four-week-old plants had the larger average number of individuals. In the second experiment four-week-old plants were infested with 0.5 female mite/cm² of leaf. The number of individuals per instar of T. urticae was recorded weekly. The highest mite production occurred between four and five weeks after infestation, indicating this to be the most suitable for mite harvesting and for plant reinfestation.
Subject(s)
Animals , Female , Pest Control, Biological/methods , Pest Control, Biological/standards , Tetranychidae/growth & development , Mites/physiology , Phaseolus/parasitology , Time FactorsABSTRACT
Este estudo foi desenvolvido visando verificar respostas fisiológicas, morfológicas e comportamentais em duas diferentes populações de Zabrotes subfasciatus (Boheman) confinadas a diferentes variedades de feijão (Phaseolus vulgaris) (Fabaceae). Avaliaram-se a longevidade, fertilidade e preferência de fêmeas por sítios de oviposição, bem como o tamanho e os níveis de assimetria flutuante de machos e fêmeas. Foram observadas respostas fisiológicas plásticas relacionadas ao tipo de dieta, sendo consideradas importantes habilidades adaptativas para manutenção do hábito generalista do inseto no consumo e uso de sítios para oviposição. As populações estudadas apresentaram respostas distintas a tratamentos similares, o que indica variações genéticas, fisiológicas e comportamentais no seu potencial plástico. O princípio de Hopkins, que mostra a influência da experiência prévia na escolha de sítios para oviposição, não foi confirmado. A ocorrência de assimetria flutuante é variável em machos e fêmeas, o que evidencia a influência de fatores genômicos na determinação desse caráter.
This study was developed aiming to verify physiological, morphological and behavioral responses of two different Zabrotes subfasciatus (Boheman) populations to different beans varieties (Phaseolus vulgaris) (Fabaceae). Female longevity, fertility and oviposition preference site, as well as size and levels of fluctuating asymmetry for males and females were described. Zabrotes subfasciatus displayed physiological plasticity in response to the diet, which was considered an important adaptive ability to maintain the insect generalist habit for food consumption and oviposition sites. The populations studied had different responses to the same treatments, indicating genetic, physiological and behavioral variation on their plastic potential. The Hopkins principle, which determines the influence of previous female experience in the choice of oviposition sites, was not confirmed. The occurrence of fluctuating asymmetry in males and females was variable, probably as a consequence of genomic factors determining this trait.
Subject(s)
Animals , Female , Male , Behavior, Animal , Coleoptera/anatomy & histology , Coleoptera/physiology , Phaseolus/parasitologyABSTRACT
O presente trabalho objetivou avaliar o desenvolvimento de Zabrotes subfasciatus (Boh.), praga de grãos armazenados, em genótipos de feijoeiro (Phaseolus vulgaris L.) comumente cultivados no Paraná e com arcelina, e a possível resistência desses materiais ao bruquíneo. Foram realizados testes em laboratório (27°C, 50 ± 10 por cento UR, fotofase 12h) com os genótipos TPS-Bionobre, IAC-Una, IPR-Uirapuru, IAPAR 44, IPR Juriti, IAPAR 81, Pérola, Carioca e Bolinha, além de dois outros contendo arcelina, Arc 1 e Arc 2. Os genótipos com os alelos Arc 1 e 2 sugerem resistência do tipo antibiose, com elevada mortalidade das fases imaturas, e Arc 1, com período de desenvolvimento prolongado e drástica redução de peso de machos e fêmeas. A resistência do tipo não-preferência para oviposição não foi observada para estes dois genótipos. Dentre os genótipos sem arcelina, IAPAR 44 destacou-se como o mais resistente a Z. subfasciatus, pois foi o menos preferido para oviposição, promovendo baixo percentual de ovos viáveis, longo período de desenvolvimento e reduzido peso de machos e fêmeas. As cultivares Pérola, IPR Juriti e Bolinha foram os mais suscetíveis, com alto número de ovos e ovos viáveis, além de baixa porcentagem de mortalidade de fases imaturas.
This research intended to evaluate the development of Zabrotes subfasciatus (Boh.), a stored-grain pest, on bean genotypes (Phaseolus vulgaris L.) commonly cultivated in the State of Parana and containing arcelin, and the possible resistance of these genotypes to the bruchine. Tests were performed under laboratory conditions (27°C, fotophase 12h, 50 ± 10 percent RH) with the genotypes TPS-Bionobre, IAC-Una, IPR-Uirapuru, IAPAR 44, IPR Juriti, IAPAR 81, Pérola, Carioca, Bolinha, and two others containing arcelin, Arc 1 and Arc 2. The genotypes with Arc 1 and 2 alleles caused higher mortality of immature stages; in Arc 1 developmental period was prolonged and the male and female dry weights were the lowest, suggesting an antibiosis mechanism of resistance. Non-preference for oviposition was not observed for these two genotypes. Among varieties without arcelin, IAPAR 44 was the most resistant to the bruchid, being the least preferred for oviposition, and promoting low percentage of viable eggs, long developmental period and reduced male and female adult dry weight. Perola, IPR Juriti and Bolinha with high number of eggs and viable eggs, low mortality of immature stages, were the most susceptible.
Subject(s)
Coleoptera/anatomy & histology , Coleoptera/metabolism , Coleoptera/parasitology , Phaseolus/microbiology , Phaseolus/parasitologyABSTRACT
Visando averiguar a presença de parasitóides do gênero Trichogramma, para utilização no controle biológico de pragas na cultura do feijão-vagem, foram coletadas posturas de Urbanus proteus (L.) que apresentavam ovos com características de parasitismo (ovos escuros). Os ovos foram encaminhados ao laboratório, onde se observou 44,9 por cento de parasitismo. Constatou-se a viabilidade de 96.3 por cento, com a média de 6,6 indivíduos por ovo e razão sexual de 0,93. Espécimes machos foram identificados, mostrando tratar-se de Trichogramma bruni Nagaraja, espécie que até então não havia sido descrita nesse hospedeiro e cultura.
Aiming to verify the presence of eggs parasitoids of the genus Trichogramma, for using in the biological control of insects pests, were collected eggs from long tailed skipper butterfly, a lepidopteran defoliator of snap beans, which presented eggs with parasitism characteristics (dark eggs). The eggs were taken to the laboratory were 44.9 percent of parasitism was verified. Viability was 96.3 percent, with an average of 6.6 individuals per egg and a sexual ratio of 0.93. Male specimens were identified as Trichogramma bruni Nagaraja. It is the first report of parasitism in this host and culture.
Subject(s)
Animals , Hymenoptera , Lepidoptera/parasitology , Phaseolus/parasitology , Ovum/parasitologyABSTRACT
The effect of 2-tridecanone vapor on the cowpea weevil (Callosobruchus maculatus) development was determined. Seeds of cowpea were infested with adults and exposed to different doses of 2-tridecanone isolated from Pilocarpus microphyllus Stapf ex Holm, a plant species native from northeastern Brazil. The pure monoterpene was evaluated both undiluted as well as in the dilutions 1:10, 1:100 and 1:1,000 (v/v). The following parameters of the cowpea weevil life cycle were analyzed in response to decreasing doses of 2-tridecanone: number of eggs laid, percentage of egg hatching on seeds, percentage of adult emergence, adult weight at emergence, mean developmental time and number of adults emerged. Vapor of 2-tridecanone caused a significant (P < 0.05) reduction in the number of eggs laid, in the percentage of eggs hatched and in the number of emerged adults in infested seeds. The fumigant insecticidal effect of 2-tridecanone was mainly due to its ovicidal activity.
O efeito dos vapores da 2-tridecanona sobre o caruncho do feijão-de-corda (Callosobruchus maculatus) foi avaliado. Sementes de feijão-de-corda infestados com insetos adultos foram expostas a diferentes doses de 2-tridecanona isolada de Pilocarpus microphyllus, uma espécie nativa do Nordeste do Brasil. O monoterpeno puro foi utilizado nas diluições 1:10, 1:100 e 1:1000 (v/v). Os parâmetros da biologia do inseto foram analisados em função da resposta a doses decrescentes de 2-tridecanona: número de ovos postos por fêmea, percentagem de eclosão de ovos, percentagem de emergência de adultos, peso dos adultos recém-emergidos, tempo médio de desenvolvimento e número total de ovos emergidos. Diferenças significativas (P < 0.05) entre as doses de 2-tridecanona testadas foram observadas, para quatro dos seis parâmetros biológicos analisados. Os resultados obtidos indicaram que a 2-tridecanona é tóxica para C. maculatus, reduzindo significativamente (P < 0.05) o número de insetos emergidos após a infestação. Esse efeito foi causado principalmente pela significativa redução observada na eclosão dos ovos expostos ao vapor da substância.