title: Toxicity of spinosad to temephos-resistant Aedes aegypti populations in Brazil.
abstract: The mosquito Aedes aegypti is the primary vector of different arboviruses and represents a major public health problem. Several Brazilian populations of Ae. aegypti have developed resistance to temephos, the most used organophosphate larvicide. New tools which are less harmful to the environment and safer for humans are becoming increasingly important to control this insect vector. Spinosad, an aerobic fermentation product of a soil actinobacteria, has a favorable environmental profile. It presents selective insecticide properties, a mechanism of action that differs from those of many synthetic chemical insecticides. The toxicity of spinosad and temephos to Aedes aegypti populations from Brazil, which were previously exposed to temephos, were investigated in this study. Larval susceptibility (LC50) to temephos varied from 3μg/L for Rockefeller up to 260 μg/L for Santana do Ipanema field derived population. Larval susceptibility (LC50) to spinosad varied from 23μg/L for Rockefeller up to 93μg/L for Marilia field derived population. In addition, a semi-field trial was performed to evaluate spinosad (NatularTM DT) initial efficacy and persistence toward four field-derived lineages and the Rockefeller lineage, used as an internal control. Spinosad was tested at 0.5mg active ingredient/L in 200L capacity water tanks. Mortality was recorded each 24 hours after exposition and tanks were further recolonized once per week with mortality being recorded daily for eight weeks. Spinosad provided a level equal or superior to 80% mortality during a seven to eight week evaluation period. The assessed populations did not present cross-resistance between spinosad and temephos in laboratory conditions. It demonstrates that spinosad may be a promising larvicide for the control of Ae. aegypti, especially for populations in which resistance to temephos has been detected.
authors.affiliation: Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ-Brasil.|Laboratório de Entomologia, Instituto de Biologia do Exército, Rio de Janeiro, RJ-Brasil.
authors.forename: Luciana
authors.initials: L
authors.lastname: Dos Santos Dias
authors.affiliation: Superintendência de Controle de Endemias, Marília, SP-Brasil.
authors.forename: Maria de Lourdes da Graça
authors.initials: ML
authors.lastname: Macoris
authors.affiliation: Superintendência de Controle de Endemias, Marília, SP-Brasil.
authors.forename: Maria Teresa Macoris
authors.initials: MT
authors.lastname: Andrighetti
authors.affiliation: Superintendência de Controle de Endemias, Marília, SP-Brasil.
authors.forename: Vanessa Camargo Garbeloto
authors.initials: VC
authors.lastname: Otrera
authors.affiliation: Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ-Brasil.|Laboratório de Entomologia, Instituto de Biologia do Exército, Rio de Janeiro, RJ-Brasil.
authors.forename: Adriana Dos Santos
authors.initials: AD
authors.lastname: Dias
authors.affiliation: Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ-Brasil.|Laboratório de Entomologia, Instituto de Biologia do Exército, Rio de Janeiro, RJ-Brasil.
authors.forename: Luiz Guilherme Soares da Rocha
authors.initials: LG
authors.lastname: Bauzer
authors.affiliation: Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ-Brasil.|Laboratório de Entomologia, Instituto de Biologia do Exército, Rio de Janeiro, RJ-Brasil.
authors.forename: Cynara de Melo
authors.initials: CM
authors.lastname: Rodovalho
authors.affiliation: Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ-Brasil.|Laboratório de Entomologia, Instituto de Biologia do Exército, Rio de Janeiro, RJ-Brasil.
authors.forename: Ademir Jesus
authors.initials: AJ
authors.lastname: Martins
authors.affiliation: Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ-Brasil.|Laboratório de Entomologia, Instituto de Biologia do Exército, Rio de Janeiro, RJ-Brasil.
authors.forename: José Bento Pereira
authors.initials: JB
authors.lastname: Lima
mesh_terms: D000330:Aedes / Q000187:drug effects* / Q000254:growth & development; D000818:Animals; D001938:Brazil; D004338:Drug Combinations; D006801:Humans; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D018942:Macrolides / Q000633:toxicity*; D000002:Temefos / Q000494:pharmacology*
chemical_list: D004338:Drug Combinations; D007306:Insecticides; D018942:Macrolides; D000002:Temefos; C415329:spinosad