Resumo -A cobertura do solo é o fator de maior importância relativa no controle da erosão hídrica. Assim, objetivou-se no presente estudo elaborar a modelagem da cobertura vegetal de vinte e quatro plantas de cobertura, em diversos sistemas de plantio e históricos de uso, com potencial para cultivo no Sul de Minas Gerais. Para avaliação da cobertura vegetal foram realizadas avaliações no campo utilizando uma régua de classificação da cobertura vegetal, sendo o delineamento experimental inteiramente casualizado, com três repetições, utilizado neste experimento. As plantas cultivadas sobre a palhada de feijão irrigado apresentaram alto índice de cobertura do solo, o que pode estar relacionado à maior disponibilidade de nutrientes deixado por esta cultura na palhada e a maior reserva de água no solo, promovido pela irrigação do feijão. O milheto cultivado em nível e sobre a palhada de milheto e feijão-de-porco apresentou o menor índice de cobertura entre as plantas testadas. Na região sul de Minas Gerais os padrões de chuvas ocorrem em maior quantidade nos períodos de outubro a março, com elevação em dezembro e janeiro. Neste período o solo deve estar protegido do impacto da gota de chuva, pois o risco de erosão hídrica é maior. Assim, a utilização das plantas de cobertura é de grande importância, pois estas protegem o solo do impacto direto das gotas de chuvas e diminuem os picos de temperatura do solo, sendo que estas devem ser cultivadas, preferencialmente, sobre a palhada de feijão.Palavras-Chave -Índice de cobertura vegetal. Erosão hídrica. Sustentabilidade. Chuvas intensas. Abstract -The ground cover is the most important factor relative to control erosion. Thus, the objective of this study was to develop a model plant cover for 24 cover crops used in several cropping systems and historical use, with potential for cultivation in southern Minas Gerais State, Brazil. To evaluate the vegetation cover field assessments using the strip land cover classification. A completely randomized design with three replications was used in this experiment. Plants grown on irrigated bean straw demonstrated a high rate of soil cover, which may be related to the increased availability of nutrients left by this culture in the straw and the largest water reserve in the soil, promoted by irrigation of beans. The level and millet grown on the millet straw and jack-bean had the lowest rate of coverage among the plants valuated. In the region southern of Minas Gerais, the precipitation pattern is predominant duirng October to March, with an increase in December and January. In this period the soil should be protected from raindrop impact, because the risk of erosion is greater. Thus, the use of cover crops is of great importance, because they protect the soil from direct impact of raindrops and reduce temperature peaks of the soil, since they must be grown, preferably on the bean straw.

Vitellogenin (Vg) plays a vital role in the reproduction of oviparous species, as the precursor of the major egg storage protein. In bees, most of the studies of this protein rely on honey bees (Apis mellifera ), and very little is known in solitary species. The solitary bees Centris tarsata and C. analis were chosen to characterize vg cDNA and better understand its expression. The Vg-deduced amino acid sequences from these bees have typical Vg features found in other hymenopterans. Besides its main site of synthesis, the fat body, transcripts of vg were also observed in ovaries. Males also showed expression of vg , although in lower levels compared with females. During development, vg expression was observed in late larvae, pupae, and female adults. The highest amounts of vg transcripts were observed in egg-laying females. Expression of vg increased rapidly in a few hours after female adult emergence, which indicates that its gene expression does not depend on mating to be triggered. vitellogenin / gene expression / males / ovaries

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