Agricultural Sciences, 2014, 5, 634-646 Published Online June 2014 in SciRes. http://www.scirp.org/journal/as http://dx.doi.org/10.4236/as.2014.57067 How to cite this paper: Lopes-da-Silva, M., Sanches, M.M., Stancioli, A.R., Alves, G. and Sugayama, R. (2014) The Role of Natural and Human-Mediated Pathways for Invasive Agricultural Pests: A Historical Analysis of Cases from Brazil. Agricul- tural Sciences, 5, 634-646. http://dx.doi.org/10.4236/as.2014.57067 The Role of Natural and Human-Mediated Pathways for Invasive Agricultural Pests: A Historical Analysis of Cases from Brazil Marcelo Lopes-da-Silva 1 , Marcio Martinello Sanches 1 , Andréa Ramos Stancioli 2 , Giliardi Alves 2 , Regina Sugayama 2 1 Plant Quarantine Laboratory, Embrapa Genetic Resources and Biotechnology, Brazilian Agricultural Research Corporation (Embrapa), Brasilia, Brazil 2 Agropec Pesquisa, Extensão e Consultoria, Belo Horizonte, Brazil Email: marcelo.lopes.silva@embrapa.br , marcio.sanches@embrapa.br Received 25 April 2014; revised 29 May 2014; accepted 18 June 2014 Copyright © 2014 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Information about the geographic distribution of agricultural pests is the basis for all pest-related agricultural and environmental protection policies. However, often the pest’s records are incom- plete and uncertain. Even with limitations, the pest records are needed for any country to organize a system for agriculture protection and to mobilize surveillance efforts. The first point is to iden- tify the imminence of biological invasions, which can be accomplished through the collection of data on pest distribution. The basic information to evaluate the predictability of an invasion is geographic distribution and the identification of pathway types associated with the potential in- vader. Thus, the level of the risk of introduction is assessed more objectively. In this article, cases of introduction of pests were analyzed from published reports in Brazil in terms of their geo- graphic distribution at the time of their introduction. Taking into consideration the country’s ex- tensive terrestrial borders, this study attempts to elucidate the role played by different pathways in each bioinvasion. This analysis recognized the limitations of the historical method and under- lying uncertainties of each invasion event. Human-mediated pathways were the main source of agricultural pest invasions in Brazil and the country was more a disperser than a receptor of exot- ic agricultural pests and diseases in South America. A new geographical hotspot (Northern South America and Caribbean Region) for possible invasions was identified. Keywords Bioinvasions, Biosecurity, Surveillance, Borders, Dispersion, Invasion Biology, Risk Analysis