Xylella fastidiosa subsp. pauca is genetically diverse and has many vector species. However, there is limited information on vector specificity and efficiency for different sequence types (STs) within the pathogen subspecies. Both STs of X. fastidiosa and vectors differ in their associations with plants; therefore, assessment of vector competence should include the standardized vector acquisition ability of bacteria from artificial diets. This work aimed to adapt and validate an in vitro acquisition system for strains of X. fastidiosa that cause citrus variegated chlorosis, and to compare the transmission efficiency of STs of subsp. pauca by different species of sharpshooter vector. First, acquisition and transmission of ST13 by Bucephalogonia xanthophis and Macugonalia leucomelas was tested using an artificial diet with bacteria grown on minimum defined medium (X. fastidiosa medium) with or without 1% galacturonic acid (GA). Subsequently, four sharpshooter species (B. xanthophis, M. leucomelas, M. cavifrons, and Sibovia sagata) were compared as vectors of ST13 acquired from artificial diets, and four STs of subsp. pauca (11, 13, 65, and 70) were tested for acquisition and transmission by M. leucomelas. The artificial system allowed efficient acquisition and transmission of ST13 to plants, with no differences between the media tested. ST13 was transmitted more efficiently by B. xanthophis and M. leucomelas when compared with M. cavifrons and S. sagata. Different STs influenced acquisition and transmission rates by M. leucomelas. The differences in vector competence, despite the standardized acquisition system, suggest that ST–vector foregut or vector–plant interactions may influence bacterial acquisition, retention and inoculation by the insect.

Aos que me ajudaram por várias vezes nos experimentos de campo, Anderson, Arthur e Cláudio, pelos dias divertidos em campo trocando quase 5.000 armadilhas e sem os quais não seria possível ter feito tal trabalho;A minha namorada, Julia Hidaka, por todo apoio e compreensão nesses anos; E a todos que direta ou indiretamente contribuíram para a realização deste trabalho. Huanglongbing (HLB) is the most important citrus disease in the world, affecting all cultivated citrus varieties, and it is very difficult to control. In Brazil, HLB is spreading in the major citrus producing areas and causing huge losses to the citriculture. Disease management depends on integration of different methods, including control of the insect vector, the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). In order to effectively monitor and control this vector, it is necessary to understand his population dynamics in citrus orchards, identifying regions and seasons where the insect develops higher populations. This study was designed to investigate the temporal and spatial dynamics of D. citri in citrus orchards of Sao Paulo State, examining the effect of different regions, seasons and plant age. Surveys of psyllid populations and citrus shoots were carried out over two years in six locations, representing three growing regions of São Paulo State, in citrus orchards of different ages, where all life stages of D. citri and citrus shoots were sampled. The spatial distribution of D. citri was analyzed by geostatistics in orchards of two municipalities of the central region of São Paulo State. The efficacy of sampling methods (yellow sticky cards vs. visual inspections) and sampling height on the tree canopy for estimating psyllid populations and number of citrus shoots was investigated as well; this particular study was conducted in two orchards of different ages, in the central region. Significant effects of region, orchard age and seasons of the year on the population of D. citri were observed. The highest insect populations are present in the central region, where the insect occurs more frequently throughout the year, followed by the northwestern and southern regions of São Paulo State. More nymphs occurred in younger orchards, but the adult population does not necessarily occur in higher numbers in the younger orchards. Spring was the season of highest populations of D. citri, but population increases can occur at any time if there are shoots present and the weather is favorable. The sampling height influenced the number of D. citri adults trapped by yellow sticky cards in the older orchard, and the numbers of psyllid eggs, nymphs and adults, as well as of citrus shoots, visualized on the younger orchard. More accurate sampling data were generated by using yellow sticky traps compared with visual inspections. Yellow sticky traps should be placed closer to the top of the citrus tree for better accuracy. D. citri showed aggregated pattern and strong spatial dependence in most sampling dates and in orchards of different...

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-Citrus black-fly (Aleurocanthus woglumi) has become an important pest in many citrusproducing regions in Brazil, causing direct and indirect damage to plants. Due to the lack of studies on the economic injury level (EIL) for this insect, control efficiency can be impaired. The objective of this research was to determine the EIL and the influence on the productivity of orange trees colonized by A. woglumi nymphs in an orchard located in the municipality of Capitao-Poço, Pará, using statistical analysis and damage prediction models through multivariate statistics. Population levels varied along the experiment. Infestation by A. woglumi nymphs negatively influenced orange production in Capitao-Poço with the highest population densities of the pest associated to lower plant productivity. NÍVEL DE DANO ECONÔMICO PARA MOSCA-NEGRA-DOS-CITROS EM ÁREA COMERCIAL DE LARANJA 'PÊRA-RIO'RESUMO -A mosca-negra-dos-citros (Aleurocanthus woglumi) tem-se tornado praga importante em diversas regiões produtoras de citros no Brasil, provocando danos diretos e indiretos às plantas. Devido à ausência de estudos acerca do nível de dano econômico deste inseto (NDE), a eficiência de controle pode ser prejudicada. O objetivo desta pesquisa foi determinar o nível de dano econômico e a influência sobre a produtividade de laranjeiras colonizadas por ninfas de A. woglumi em pomar localizado na cidade de Capitão-Poço, Pará, usando análise estatística e modelos de previsão de danos através de estatística multivariada. Os níveis populacionais variaram ao longo do experimento. A infestação por A. woglumi influenciou negativamente a produção de laranja no município de Capitão-Poço, com as maiores densidades populacionais da praga associadas à menor produtividade das plantas. O nível de infestação de laranjeiras por A. woglumi que resultou em dano econômico foi de, em média, 47,63% de plantas infestadas, com variação de 22,75 a 89,92%, e o NDE é expresso pela equação Y= 97,39 -8,43x. Termos para indexação: Aleyrodidae, Aleurocanthus woglumi, ninfas, NDE.1 (Paper 001-16).