Lima bean (Phaseolus lunatus L.) is one of the four major important grain legumes in Brazil. The occurrence of diseases has difficulted its culture and has affected grain quality of this crop. Among the most important diseases are the viruses, especially those generated from Geminivirus. The high severity of the Geminiviruses diseases is especially due to both the absence of pathogen resistance varieties and increase in the population of a new biotype (biotype B), of the insect vector, commonly named whitefly (Bemisia tabaci). This biotype transmitis the virus more efficiently and it presents a host range larger than biotype A. The present estudy objected the detection, molecular characterization and analisys of the genetic diversity of Begomovirus isolates that infects lima bean plats in Alagoas and Pernambuco States. The detection was realized by PCR technique utilizing as a mold DNA extracted from plants presenting symptoms of geminivirus infection which were colleted from seven locations of Alagoas and one of Pernambuco. It was identified Begomovirus infection in seventeen collected samples. The analisys of genetic diversity, based in PCR-RFLP, revealed that exists diversity among the isolates of Begomovirus that were infecting these plants. According to differences in the patterns of bands generated by PCR-RFLP, it was chosen three isolates (fava Maceió, fava Recife and fava União dos Palmares), in an attempt to sequence analysis. The comparison of the obtained sequences with other deposited in GenBank/NCBI allowed the classification of these isolates as Bean golden mosaic virus, the last one being the first report of infection caused this species in lima bean plants in Alagoas and Pernambuco State. / Fundação de Amparo a Pesquisa do Estado de Alagoas / A fava (Phaseolus lunatus L.) está entre as quatro espécies de leguminosas de grãos mais importantes no Brasil. A ocorrência de doenças tem dificultado o cultivo e afetado a qualidade dos grãos dessa cultura. Entre as doenças mais importantes, estão as viroses, destacando-se aquelas ocasionadas por Geminivirus. A alta severidade das doenças causadas por geminivírus, deve-se principalmente à ausência de variedades resistentes ao patógeno e também ao aumento populacional de um novo biótipo (biótipo B) do inseto vetor, vulgarmente denominado, "mosca branca" (Bemisia tabaci). Este biótipo transmite o vírus mais eficientemente e apresenta uma gama de hospedeiros mais ampla do que o biótipo A. O presente trabalho teve como objetivos principais a detecção, caracterização molecular e a análise da diversidade genética de isolados de Begomovirus que infectam plantas de fava no Estado de Alagoas e Pernambuco. A detecção foi realizada mediante a técnica de PCR utilizando como molde o DNA extraído de plantas com sintomas de infecção por geminivírus, coletadas em sete municípios de Alagoas e em um de Pernambuco. Foi diagnosticada infecção por Begomovirus em dezessete amostras coletadas. A análise da diversidade genética, baseada em PCR-RFLP, demonstrou que existe diversidade entre os isolados de begomovírus que estavam infectando estas plantas. A partir das diferenças nos padrões de bandas gerados através da PCR-RFLP, foram escolhidos três isolados (Fava Maceió, Fava Recife e Fava União dos Palmares), para fins de seqüenciamento. A comparação das seqüências obtidas, com outras seqüências depositadas do GenBank/NCBI permitiu a classificação desses isolados como Bean golden mosaic virus, sendo este o primeiro relato de infecção por esta espécie em plantas de fava, nos estados de Alagoas e Pernambuco.

The Mexican bean beetle, Epilachna varivestis Mulsant, is a major pest of snap beans, Phaseolus vulgaris L. in the Central Appalachian region of the United States. To develop pertinent research objectives, background information on this pest was gathered from literature sources and personal communications with growers, extension agents and other agricultural professionals. In objective one, Mexican bean beetle preference, developmental success and plant injury were compared among three snap bean and three lima bean cultivars in field and greenhouse trials. The cultivar 'Dragon's Tongue' was the most preferred, suitable for development, and prone to injury. Growers may benefit from growing less susceptible cultivars, or by using 'Dragon's Tongue' in trap cropping or push-pull strategies. In objective two, Mexican bean beetle densities, feeding injury, and yield were compared among snap beans grown on metallized plastic (highly reflective), white plastic, black plastic, and bare soil. Metallized plastic provided the greatest level of control, and resulted in the highest yields. Managing Mexican bean beetle by growing beans on metallized plastic may be used as a stand-alone method, or in a push-pull strategy. In the final objective, the effects of snap beans grown from thiamethoxam (a neonicotinoid insecticide)-treated seeds on Mexican bean beetle were assessed in greenhouse and field experiments. Thiamethoxam-treated plants killed 40 to 50% of Mexican bean beetle adults and larvae up to 16 days after planting. In the field, thiamethoxam-treated plants mitigated Mexican bean beetle densities and damage in one out of five experiments, resulting in a yield increase. In none of the five field experiments were differences detected in predatory arthropod species between thiamethoxam and non-insecticide treated beans. In summary, the results of this project suggest that non-chemical management methods, such as cultivar selection and planting beans on reflective mulch, can provide effective control of Mexican bean beetle. Thiamethoxam-treated seed may also provide control of this pest, but only within two to three weeks after planting; otherwise, there is typically no effect on beetles, injury or yield. This doctoral research has laid a foundation for an integrated pest management approach for Mexican bean beetle. / Ph. D. / Integrated pest management (IPM) is an economical and environmentally-sensible approach to pest management that considers numerous control and decision-making strategies. This dissertation examined non-chemical strategies and the use of an insecticide seedtreatment for management of Mexican bean beetle, a major pest of green beans in the Central Appalachian region of the United States. To develop pertinent research objectives, background information on this pest was gathered from literature sources and personal communications with growers, extension agents and other agricultural professionals. In objective one, Mexican bean beetle preference, developmental success and plant injury were compared among various bean cultivars in field and greenhouse trials. The cultivar ‘Dragon’s Tongue’ was the most suitable host for Mexican bean beetle, and consequently incurred the greatest injury. Growers in high risk areas for Mexican bean beetle may benefit from growing less susceptible cultivars. In objective two, Mexican bean beetle severity and yield were compared among green beans grown on reflective metallized plastic, white plastic, black plastic, and bare soil. Metallized plastic provided the greatest level of control, and resulted in the largest yields. Our results suggest that growing beans on reflective surfaces may be an effective, chemical-free management strategy for Mexican bean beetle. In the final objective, the effects of green beans grown from thiamethoxam (a neonicotinoid insecticide)-coated seeds was examined on Mexican bean beetle severity, non-pest arthropods, and crop performance in greenhouse and field experiments. Bean plants grown from insecticide-coated seeds were highly-toxic to Mexican bean beetle for about 16 days after planting. In one out of five experiments, thiamethoxam-treated plants reduced pest levels, resulting in increased yields. More often, Mexican bean beetles arrived after the insecticide had disappeared from plants and there was no effect. There were no detectable effects from the thiamethoxam treatment on non-pest arthropods in any experiment. Overall, seed-treatments may provide occasional control of Mexican bean beetle, but non-chemical methods may be as effective and more practical. This doctoral research project has provided a foundation for an integrated pest management approach for Mexican bean beetle.