631 © The Author(s) 2022. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. Vector Control, Pest Management, Resistance, Repellents Aquatic Macrophytes Hosting Immature Mansonia (Mansonia) Blanchard, 1901 (Diptera, Culicidae) in Porto Velho, Rondonia State, Brazil J. A. Amorim, 1,2,5, I. L. R. Sa, 1, M. V. R. Rojas, 1 N. F. Santos Neto, 3 A. K. R. Galardo, 3 D. P. Carvalho, 4 K. A. N. Ribeiro, 4 and M. A. M. Sallum 1, 1 Departamento de Epidemiologia, Faculdade de Saude Publica, Universidade de Sao Paulo, Sao Paulo, SP 01246–904, Brazil, 2 Departamento de Ciencias e Matematica, Instituto Federal de Educacao, Ciencia e Tecnologia de Sao Paulo, Sao Paulo, SP 01109- 010, Brazil, 3 Laboratório de Entomologia Medica, Instituto de Pesquisas Cientificas e Tecnologicas do Estado do Amapa, Macapa, AP 68903-419, Brazil, 4 Gerencia de Meio Ambiente, Saude e Segurança do Trabalho, Santo Antonio Energia, Porto Velho, RO 76805- 812, Brazil, and 5 Corresponding author, e-mail: jandui.amorim@usp.br M.A.M.S. is the senior author in this study. Subject Editor: Dina Fonseca Received 20 August 2021; Editorial decision 14 December 2021 Abstract High abundance of hematophagous mosquitoes of the genus Mansonia Blanchard, 1901 (Diptera: Culicidae) threatens human and domestic animal health and well-being. Knowledge of the biology of nuisance mosquito spe- cies is necessary to understand specific ecological and biological factors to enable rapid and effective monitoring measures for sustainable control programs.The establishment and dispersion of Mansonia species are associated with the occurrence of aquatic macrophytes species, which are indispensable for the development of larvae and pupae. To increase knowledge of the host plants for Mansonia immature stages in Porto Velho, Rondonia State, Brazil, specimens of four plant species, which occur across the tributaries of the Madeira River were sampled and inspected for the presence of egg batches, larvae, and pupae. A total of 1,386 larvae and pupae of Mansonia spp. were collected attached to the roots of Eichhornia crassipes (Mart.) Solms (Commelinales: Pontederiaceae), Pistia stratiotes L. (Alismatales: Araceae), and Limnobium laevigatum (Humb. and Bonpl. Ex Willd.) Heine (Alismatales: Hydrocharitaceae). The novel association of Mansonia species with L. laevigatum is presented. Egg batches of Mansonia spp. were found only on Salvinia molesta D.S. Mitch. (Salviniales: Salviniaceae). Possible differences in the roles played by E. crassipes and S. molesta in the reproductive cycle of Mansonia spp. in the surveyed area are discussed. All species of host plants including E. crassipes, P. stratiotes, S. molesta, and L. laevigatum should be considered when planning macrophyte management for the control of Mansonia species. Key words: ecology, habitat, pest, vector, control Female mosquitoes of the genus Mansonia Blanchard, 1901 feed on blood of a great variety of vertebrates (Lourenço-de-Oliveira and Heyden 1986, Alencar et al. 2005, Lorosa et al. 2010). At high pop- ulation densities, these insects cause serious disturbance to humans and domestic animals (Forattini 1965) and are considered vectors of arboviruses in the Neotropical Region. According to White and Faust (2014) some species of Mansonia can transmit the Oriboca and Bussuquara viruses (ORIV and BSQV, respectively) in South America (the authors do not cite details of mosquito species and locations). There are records of human infection by ORIV (from the States of Para and Amazonas, Brazil, and Suriname) and BSQV (from Panama); the latter virus also was isolated from Mansonia (Mansonia) titillans (Walker, 1848) from an unreported location (CDC 2021). Mansonia (Mansonia) indubitans Dyar and Shannon, 1925 and Ma. titillans are the most widely distributed species of the genus and have been implicated in the transmission of the Venezuelan equine encephalitis virus (VEEV) in Peru (Turell et al. 2000) and Venezuela (Mendez et al. 2001). Ma. titillans can carry the Journal of Medical Entomology, 59(2), 2022, 631–637 https://doi.org/10.1093/jme/tjab223 Advance Access Publication Date: 19 January 2022 Research Downloaded from https://academic.oup.com/jme/article/59/2/631/6511306 by guest on 01 April 2022