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Biology of Bemisia tabaci (Genn.) B biotype (Hemiptera, Aleyrodidae) on tomato genotypes
Oriani, Maria Auxiliadora de Godoy;Vendramim, José Djair;Vasconcelos, Cristina Jensen;
Scientia Agricola , 2011, DOI: 10.1590/S0103-90162011000100006
Abstract: brazil is one of the main tomato (solanum lycopersicum) producers worldwide. nevertheless, considerable part of the production is lost due to bemisia tabaci (genn.) b biotype attacks. resistant plants can be an important method for controlling this pest in an integrated pest management. tests for evaluating some biological aspects of b. tabaci were carried out on 18 tomato genotypes, in controlled laboratory greenhouse conditions. thirty-day-old plants placed in plastic cages were infested with 20 whitefly pairs each, for 24 h. the development of at least 30 eggs in three leaflets per plant (repetition) was observed until adult emergence. the development period of insects grown in la1335, pi365928 and la722 genotypes took three days longer when compared to the ones grown in pi134418 (20.3 days). the highest mortality rate of whitefly nymphs occurred in pi365928, la1335 and la722 genotypes (63.8, 54.5 and 53.3%, respectively), and the smallest ones in iac294 and iac68f-22-2 genotypes (4.9 e 6.2%, respectively). la1335, pi365928 and la722 genotypes presented moderate feeding nonpreference and/or antibiosis-based resistance to b. tabaci b biotype.
Genetic diversity of Bemisia tabaci (Genn.) Populations in Brazil revealed by RAPD markers
Lima, L.H.C.;Campos, L.;Moretzsohn, M.C.;Návia, D.;Oliveira, M.R.V. de;
Genetics and Molecular Biology , 2002, DOI: 10.1590/S1415-47572002000200016
Abstract: bemisia tabaci (genn.) was considered a secondary pest in brazil until 1990, despite being an efficient geminivirus vector in beans and soybean. in 1991, a new biotype, known as b. tabaci b biotype (=b. argentifolii) was detected attacking weed plants and causing phytotoxic problems in cucurbitaceae. nowadays, b. tabaci is considered one of the most damaging whitefly pests in agricultural systems worldwide that transmits more than 60 different plant viruses. little is known about the genetic variability of these populations in brazil. knowledge of the genetic variation within whitefly populations is necessary for their efficient control and management. the objectives of the present study were to use rapd markers (1) to estimate the genetic diversity of b. tabaci populations, (2) to study the genetic relationships among b. tabaci biotypes and two other whitefly species and (3) to discriminate between b. tabaci biotypes. a sample of 109 b. tabaci female individuals obtained from 12 populations in brazil were analyzed and compared to the a biotype from arizona (usa) and b biotype from california (usa) and paraguay. trialeurodes vaporariorum and aleurodicus cocois samples were also included. a total of 72 markers were generated by five rapd primers and used in the analysis. all primers produced rapd patterns that clearly distinguished the bemisia biotypes and the two other whitefly species. results also showed that populations of the b biotype have considerable genetic variability. an average jaccard similarity of 0.73 was observed among the b biotype individuals analyzed. cluster analysis demonstrated that, in general, brazilian biotype b individuals are scattered independently in the localities where samples were collected. nevertheless, some clusters were evident, joining individuals according to the host plants. amova showed that most of the total genetic variation is found within populations (56.70%), but a significant portion of the variation is found between crop
Genetic diversity of Bemisia tabaci (Genn.) Populations in Brazil revealed by RAPD markers  [cached]
Lima L.H.C.,Campos L.,Moretzsohn M.C.,Návia D.
Genetics and Molecular Biology , 2002,
Abstract: Bemisia tabaci (Genn.) was considered a secondary pest in Brazil until 1990, despite being an efficient geminivirus vector in beans and soybean. In 1991, a new biotype, known as B. tabaci B biotype (=B. argentifolii) was detected attacking weed plants and causing phytotoxic problems in Cucurbitaceae. Nowadays, B. tabaci is considered one of the most damaging whitefly pests in agricultural systems worldwide that transmits more than 60 different plant viruses. Little is known about the genetic variability of these populations in Brazil. Knowledge of the genetic variation within whitefly populations is necessary for their efficient control and management. The objectives of the present study were to use RAPD markers (1) to estimate the genetic diversity of B. tabaci populations, (2) to study the genetic relationships among B. tabaci biotypes and two other whitefly species and (3) to discriminate between B. tabaci biotypes. A sample of 109 B. tabaci female individuals obtained from 12 populations in Brazil were analyzed and compared to the A biotype from Arizona (USA) and B biotype from California (USA) and Paraguay. Trialeurodes vaporariorum and Aleurodicus cocois samples were also included. A total of 72 markers were generated by five RAPD primers and used in the analysis. All primers produced RAPD patterns that clearly distinguished the Bemisia biotypes and the two other whitefly species. Results also showed that populations of the B biotype have considerable genetic variability. An average Jaccard similarity of 0.73 was observed among the B biotype individuals analyzed. Cluster analysis demonstrated that, in general, Brazilian biotype B individuals are scattered independently in the localities where samples were collected. Nevertheless, some clusters were evident, joining individuals according to the host plants. AMOVA showed that most of the total genetic variation is found within populations (56.70%), but a significant portion of the variation is found between crops (22.73%). The present study showed that the B biotype is disseminated throughout the sampled areas, infesting several host plants and predominates over the A biotype.
Resistance of Soybean Genotypes to Bemisia tabaci (Genn.) Biotype B (Hemiptera: Aleyrodidae)
Vieira, SS;Bueno, AF;Boff, MIC;Bueno, RCOF;Hoffman-Campo, CB;
Neotropical Entomology , 2011, DOI: 10.1590/S1519-566X2011000100018
Abstract: the silverleaf whitefly bemisia tabaci (genn.) biotype b has become a serious problem for soybean cultivation because it can significantly reduce soybean productivity. the use of soybean cultivars resistant to whitefly attack is an important strategy in an integrated pest management (ipm) program. this study evaluated the preference for oviposition and colonization by b. tabaci biotype b on different soybean genotypes. in the free-choice test, the genotypes studied were 'iac 17' and 'iac 19' as the standards for resistance and 'iac holambra stwart' as the standard for susceptibility, as well as babr01-0492, babr01-0173, babr01-1259, babr01-1576, babr99-4021hc, babr99-4021hp, 'barreiras', 'conquista', 'corisco', 'brs gralha', pi274454, pi227687, and pi171451. in the no-choice test, the four best genotypes selected in the free-choice test, in addition to the susceptible and resistant standards were evaluated. our data indicated 'barreiras' as the most resistant genotype against b. tabaci biotype b. 'brs gralha', which was the least attractive to whitefly adults in the free-choice test, did not show resistance to insect attack when they were confined in cages in the no-choice test. despite the high number of eggs observed, babr01-1576 and babr99-4021hc showed a reduced number of nymphs, indicating antibiosis. the genotypes with a high level of resistance can be used as a tool against b. tabaci in ipm or as a source of resistance in plant-breeding programs.
Presen a e impacto de Bemisia Tabaci (genn.) (homoptera: aleyrodidae) em culturas hortícolas em Portugal Presence and impact of Bemisia Tabaci (genn.) (homoptera: aleyrodidae) in vegetable crops in Portugal
Célia Mateus,Fernanda Amaro,Diamamtina Louro,António Mexia
Revista de Ciências Agrárias , 2008,
Abstract: Em Portugal, emisia tabaci (Genn.) (Homoptera: Aleyrodidae) foi detectada pela primeira vez em 1992, em culturas hortícolas. Desde 1995, é uma praga importante no Algarve, onde está presente nas estufas durante todo o ano, com níveis de infesta o elevados no Ver o. A partir de 2006, foi considerada também estabelecida no Alentejo e em parte do Ribatejo e Oeste. A espécie constitui um grave problema em diversas culturas hortícolas, n o só pelos prejuízos directos, mas, principalmente, pela sua capacidade de transmitir vírus de plantas. As culturas mais atacadas s o as de tomate e de cucurbitáceas, em estufa. A protec o integrada é a melhor forma de minorar este problema de modo sustentável, embora a presen a de vírus dificulte a respectiva implementa o e sucesso. Neste trabalho, apresentam-se os resultados da investiga o desenvolvida em Portugal sobre esta espécie, nomeadamente: distribui o geográfica, bioecologia, identifica o de biótipos, transmiss o de vírus, estimativa do risco, prospec o de auxiliares e meios de luta. Sugerem-se ainda futuras linhas de trabalho. In Portugal, emisia tabaci (Genn.) (Homoptera: Aleyrodidae) was first recorded in 1992, in horticultural crops. Since 1995, it has been an important pest in the Algarve, southern Portugal, where it is present the whole year round, in greenhouse crops, with high infestations during the summer. In 2006, it was installed in Alentejo and in part of Ribatejo e Oeste region. It is a serious problem to several vegetable crops, due to direct damages, but mainly by transmitting plant viruses. The most severely affected crops are greenhouse tomato and cucurbits. IPM is considered the best way to deal with the sustainable management of this problem, but the presence of viruses complicates the implementation of IPM programs. The work presented here gives an overview of the results obtained by the research activities carried out in Portugal concerning B. tabaci: geographical distribution, bioecology, biotypes identification, virus transmission, risk assessment, natural enemies’ survey and control methods. Future research work is suggested.
Virulence of entomopathogenic fungi against nymphs of Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) Virulência de fungos entomopatogênicos a ninfas de Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae)  [cached]
Michele Potrich,Pedro Manuel Oliveira Janeiro Neves,Luis Francisco Angeli Alves,Mariana Pizzatto
Semina : Ciências Agrárias , 2011,
Abstract: The objective of this study was to evaluate the pathogenicity and virulence of isolates of Beauveria bassiana (Unioeste 47 and Unioeste 57), Metarhizium anisopliae (Unioeste 43 and Esalq 09) and Isaria sp. (IBCB 367 a d IBCB 394) against Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae). Suspensions of the isolates (1.0 × 109 conidia/mL) were sprayed on third instar nymphs on cabbage leaves. It was performed four replications, each one with 20 insects, for each treatment. The control consisted of sterile distilled water + Tween 80 (0.01%). The number of killed nymphs was evaluated during seven days, and then they were kept in a moist chamber. To estimate the median lethal concentration (LC50), isolates suspensions of 1.0 × 105, 1.0 × 106, 1.0 × 107, 1.0 × 108 and 1.0 × 109 conidia/mL were sprayed on third instar nymphs. The number of nymphs with confirmed mortality was evaluated. The isolates B. bassiana Unioeste 47 (84.1%) and Isaria sp. IBCB 367 (98.6%) did not differ significantly, causing the highest mortalities. However, the isolate M. anisopliae Esalq 09 caused the lower confirmed mortality (23.2%). The LC50 of the B. bassiana isolates varied from 1.8 × 105 and 4.1 × 105 conidia/mL (Unioeste 57 and Unioeste 47, respectively). Among the isolates of M. anisopliae, Esalq 09 presented the highest LC50 value (7.8 × 108 conidia/mL), whereas Unioeste 43 presents the lowest (4,3 × 105 conidia/mL). The Isaria sp. isolates presented LC50 of 2.5 × 105 and 3.1 × 105 conidia/mL (IBCB 367 and IBCB 394, respectively). Therefore, B. bassiana Unioeste 47 e Isaria sp. IBCB 367 isolates had potential to B. tabaci control and for future field studies. O objetivo deste trabalho foi avaliar a patogenicidade e a virulência dos isolados de Beauveria bassiana (Unioeste 47 e Unioeste 57), Metarhizium anisopliae (Unioeste 43 e Esalq 09) e Isaria sp. (IBCB 367 e IBCB 394) a Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae). Suspens es dos isolados (1,0 × 109 conídios/ mL) foram pulverizadas sobre ninfas de 3o ínstar aderidas às folhas de couve. Para cada tratamento foram realizadas quatro repeti es, com 20 insetos cada. A testemunha constou de água destilada esterilizada + Tween 80 (0,01%). Avaliou-se o número de ninfas mortas durante sete dias, que foram, posteriormente, mantidas em camara úmida. Para a estimativa da concentra o letal média (CL50) as suspens es dos isolados (1,0 × 105, 1,0 × 106, 1,0 × 107, 1,0 × 108 e 1,0 × 109 conídios/mL) foram pulverizadas sobre ninfas de 3o ínstar. Avaliou-se o número de ninfas com mortalidade confirmada pelo fungo. Os isolados B. bass
UTILIZATION OF THE BEFENTHRIN IN CHEMICAL CONTROL OF WHITE FLY (Bemisia tabaci, Genn. 1889) IN BEAN CROPS AVALIA O DO BEFENTHRIN NO CONTROLE DA MOSCA BRANCA (Bemisia tabaci, Genn. 1889) EM FEIJOEIRO
Ant?nio Lopes da Silva,Valquíria Rocha dos Santos Veloso,Ildeu Matias do Nascimento,Jaison Pereira de Oliveira
Pesquisa Agropecuária Tropical , 2007, DOI: 10.5216/pat.v23i1.2623
Abstract: The white fly (Bemisia tabaci), an important pest of bean crops, is known as vector of golden-yellow-mosaic virus in many regions in Brazil. In order to determine the efficiency of the befenthrin to control the white fly, a field experiment was carried out in Goiania, State of Goiás, Brazil. The treatments and dosage in grams of active ingredient by ha were: befenthrin (2.5; 3.75; 5.0 and 6.25), metamidophós (420.0 and 600.0) and untreated check. Results obtained by this test permitted to conclude that befenthrin at experimented doses, presented similarity of control to the other used compound in different estimations realized, with control average superior to 96.0%. Com o objetivo de avaliar a eficiência do Befenthrin 25 CE, nas dosagens de 2,5 ; 3,75; 5,00 e 6,25g i.a/ha, no controle químico da mosca branca (Bemisia tabaci Genn., 1889) em feijoeiro, foi conduzido um experimento no Campo Experimental da Escola de Agronomia da Universidade Federal de Goiás - Goiania, safra 91/92, utilizando como produto padr o o Metamidophós 600 BR nas dosagens de 420 e 600g i.a/ha. As pulveriza es foram realizadas nos 7°, 14°, 21° e 28° dias após a emergência das plantulas, utilizando-se um pulverizador costal a CO2 com bico D3 gastando-se 250 litros de calda por ha. Dois dias após a última pulveriza o foi realizada a avalia o de eficiência, contando-se o número de ninfas vivas em 10 folíolos/parcela e, 10 dias após, fez-se a contagem do número de plantas com sintomas de “mosaico dourado” por parcela. Pelos resultados obtidos, conclui-se que o Befenthrin nas dosagens de 5,0 e 6,25g i.a./ha controlou eficientemente a praga, igualando-se ao metamidophós na dosagem de 600g i.a/ha, com a vantagem de menor toxicidade para mamíferos e também sob o ponto de vista ecológico, pois a dose utilizada i.a, é 100 vezes menor.
Biology of Bemisia tabaci (Genn.) B-biotype and parasitism by Encarsia formosa (Gahan) on collard, soybean and tomato plants
Takahashi, Karina Manami;Berti Filho, Evoneo;Louren??o, André Luiz;
Scientia Agricola , 2008, DOI: 10.1590/S0103-90162008000600011
Abstract: the silverleaf whitefly bemisia tabaci (genn.) b-biotype (= b. argentifolii) (hemiptera: aleyrodidae) is a polyphagous insect attacking many plant species of economic importance. a comparison study was conducted on the duration of the egg-to-adult period, and the percentage of hatching eggs of bemisia tabaci (genn.) b-biotype on collard (brassica oleracea l. var. acephala d.c.), soybean(glycine max (l.) merr.) and tomato (lycopersicon esculentum mill.) plants, as well as the egg-to-adult period of encarsia formosa (gahan) on the 1st, 2nd, 3rd and 4th whitefly nymphal instars on these three plant species. the experiments were conducted in a laboratory (25oc, 70 ± 10% rh, 14-hour photophase). the duration of the egg-to-adult period of b. tabaci was 19.8 days on collard, 21.2 days on soybean and 22.0 days on tomato. the number of hatched eggs was higher on collard when compared to soybean and tomato plants. concerning e. formosa regardless of plant species, the duration for the egg-to-adult period was shorter for the 3rd and 4th instar nymphs as compared with the other instars.
Resistência de genótipos de abobrinha a Bemisia tabaci (Genn.) biótipo B (Hemiptera: Aleyrodidae)
Baldin, Edson L L;Beneduzzi, Ronaldo A;Souza, Douglas R;Souza, Efrain S;
Neotropical Entomology , 2009, DOI: 10.1590/S1519-566X2009000400015
Abstract: field assays were performed to evaluate the attractiveness and the non-preference of whitefly bemisia tabaci (genn.) biotype b for oviposition on squash genotypes (cucurbita pepo) and to observe the susceptibility of genotypes (novita, sandy, caserta cac melhorada, novita plus, samira, bianca, af-2858 and caserta ts) to silverleaf symptoms. the sandy genotype was the least attractive to whitefly, while novita plus, af-2858 and samira were the most attractive. the caserta cac melhorada genotype was the least preferred for oviposition. the sandy and af-2858 genotypes were the most productive, with the highest mean of fruits produced. the lowest silverleaf symptoms index was observed for the sandy and caserta cac melhorada genotypes.
Exigências Térmicas de Bemisia tabaci (Genn.) Biótipo B (Hemiptera: Aleyrodidae)
ALBERGARIA, NUNO M.M.S.;CIVIDANES, FRANCISCO J.;
Neotropical Entomology , 2002, DOI: 10.1590/S1519-566X2002000300003
Abstract: the development (egg-adult) of bemisia tabaci (genn.) b-biotype (=bemisia argentifolii, bellows & perring), was studied in field conditions and in incubators at constant temperatures (15, 20, 25, 30 and 35±1oc), using soybean, glycine max (l.) merrill, msoy 8001, as host plant. the temperatures threshold (tb) and the thermal constant (k) for egg, nymph and life cycle (egg-adult) were 11.1oc / 98.8 degree-days; 6.8oc / 383.8 degree-days and 8.3oc / 472.6 degree-days, respectively. at the temperatures of 15oc and 35oc, insect viability was smaller. in the field, 70% of the adults emerged after 413,2 degree-day were accumulated. the degree-day pattern used was adequate for the previewing bemisia tabaci b-biotype adult occurrence in field, and it can also be used to determine the number of generations in different areas of the country.
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