Interação de Tomato severe rugose virus com Bemisia tabaci biótipo B, a acessos de Capsicum spp. e ocorrência de espécies de mosca-branca no Estado de São Paulo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Resistência de genótipos de Cucurbita spp. à Bemisia tabaci biótipo B (Hemiptera: aleyrodidae) e interação com extratos vegetais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Antibiose e não preferência para oviposição de Bemisia tabaci (Genn.) biótipo B (Hemiptera: Aleyrodidae) em genótipos de feijoeiro comum

O feijoeiro comum, Phaseolus vulgaris L., constitui importante fonte de proteína e renda para muitos países, entre eles, o Brasil. Diferentes fatores contribuem para a redução da produção, como os insetos pragas, destacando-se Bemisia tabaci (Genn.) biótipo B. O presente trabalho teve por objetivo identificar genótipos de feijoeiro comum resistentes à B. tabaci biótipo B e os tipos de resistência envolvidos. Para isso, foram realizados dois experimentos desenvolvidos em laboratório e em casa-de-vegetação, avaliando-se 11 genótipos de feijoeiro comum. Para o teste com chance de escolha, o delineamento utilizado foi o de blocos casualizados, e para os testes sem chance de escolha e antibiose, a escolha foi pelo inteiramente casualizado, totalizando seis repetições para cada teste. As variáveis avaliadas foram: período de incubação dos ovos; período ninfal; período de ovo a adulto; viabilidade de ovo a adulto e longevidade de adultos. O genótipo IAC-Harmonia prolongou os períodos ninfal e de ovo a adulto de B. tabaci biótipo B. Os genótipos testados foram igualmente ovipositados pela mosca-branca, em testes com e sem chance de escolha.

Atratividade para adultos e preferência para oviposição de Bemisia tabaci (Genn.) biótipo B (Hemiptera: Aleyrodidae) em genótipos de Cucurbita spp

The objective was to evaluate the oviposition preference and attractiveness of squash genotypes (Cucurbita spp.) to Bemisia tabaci biotype B. For bioassays, B. tabaci rearing biotype B was kept under greenhouse conditions. Twenty genotypes of Cucurbita spp. ('Alicia AF 9354', 'Aline AF 9353', 'Golden Delight', 'Nova Caravela', 'Menina Morena', 'Novita', 'AF-6741', 'Atlas', 'Barbara 305', 'Menina Brasileira', 'Caserta', 'Itapua 301', 'Tamara', 'Samira', 'Canhao Seca Gigante', 'Exposicao', 'Novita Plus', 'Daiane', 'Formosa', 'Sandy') were evaluated in trials (attractiveness and oviposition choice), under laboratory and greenhouse. The attractiveness (adults/cm(2)) was assessed et 12, 24, 48 and 72 hours after release. After 72 hours leaves were collected for counting the number of eggs (free choice). The area of the sheets were measured to obtain the number of eggs/cm(2) number of adults and / cm(2). The attractiveness index s (AI) and oviposition preference index (OPI) were calculated, and the genotype 'Novita' was adopted as the standard susceptible. The genotype 'Golden Delight' was the most attractive to adults of B. tabaci biotype B. 'Sandy' 'Daiane' and 'Formosa' showed low attractiveness and 'Golden Delight' was the most atractive to B. tabaci biotype B adults. 'Sandy', 'Exposicao', 'Daiane', 'Atlas', 'Tamara' and 'Formosa' expressed no preference for free choise assay. According to the attractiveness index (AI) the genotype 'Golden Delight' was the most attractive to adults of B. tabaci biotype B, and between repellents stood out 'Sandy', 'Daiane', 'Formosa', 'Novita Plus', 'Atlas', 'Barbara 305', 'Canhao Seca Gigante' and 'Menina Brasileira'. The genotypes 'Nova Caravela', 'Golden Delight', 'Aline AF 9353' and 'Samira' are considered by stimulating oviposition preference index (OPI), while the genotypes 'Sandy', 'Exposicao', 'Daiane', 'Atlas', 'Tamara', 'Formosa', 'Menina Morena' and 'Itapua 301' were considered deterrents.

Characterization of antibiosis to the silverleaf whitefly Bemisia tabaci biotype B (Hemiptera: Aleyrodidae) in cowpea entries

The silverleaf whitefly, Bemisia tabaci (Gennadius) biotype B (Hemiptera: Aleyrodidae), is considered one of the most important pests of cowpea (Vigna unguiculata L. Walp.), limiting the productivity of this crop worldwide. Chemical control is still the main strategy for the management of populations of this insect. However, due to the harmful effects of pesticides on the environment and to humans, less injurious alternatives have been investigated. Along this line, the use of resistant genotypes can be a valuable tool for the control of the silverleaf whitefly. In this paper, we investigate some biological aspects of B. tabaci biotype B confined on 14 genotypes of cowpea. We evaluated the incubation period, egg viability, duration of nymphal stages, total duration of the juvenile phase, instar mortality and total mortality of the immature stage. The genotype MNC 99-541 F21 exhibited antibiosis against the whitefly, prolonging the lifecycle of the insect. The genotypes Canapu, BRS-Urubuquara and TE97-304 G-4 also exhibited antibiosis, causing high nymphal mortality. These results may help in breeding programmes to develop cowpea lines with resistance to B. tabaci biotype B.

Antibiosis in Soybean Genotypes and the Resistance Levels to Spodoptera eridania (Cramer) (Lepidoptera: Noctuidae)

The southern armyworm (SAW) Spodoptera eridania (Cramer) is one of the most common armyworm species defoliating soybeans. Preliminary screening trials have indicated that some soybean genotypes exhibit resistance to SAW. Therefore, in this study, we evaluated the development of SAW larvae fed on ten soybean genotypes in order to identify genotypes with antibiosis-type resistance. Neonate SAW larvae were daily fed with young leaves collected from plants at the vegetative growth stages V4-V5. Larval development and survival were recorded. Genotypes PI 227687 and PI 227682 delayed larval, pupal, and larva-adult development and yielded larvae with the lowest weight and survival and pupae with the lowest weight. Genotypes IAC 100 and DM 339 also negatively affected larval and pupal development and larval survival but at a lower level. Based on our results, the soybean lines PI 227687 and PI 227682 could be used as sources of genes for soybean breeding programs aiming to develop high yield, SAW-resistant cultivars. Moreover, further trials must be carried out under field conditions to validate if the commercial cultivars IAC 100 and DM 339, which expressed moderate levels of antibiosis-type resistance in the laboratory, are effective in suppressing SAW larvae populations.

Impedance-derived electrochemical capacitance spectroscopy for the evaluation of lectin-glycoprotein binding affinity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)