title: Effect of a spray formulation on the reproductive parameters of a susceptible population of Rhipicephalus (Boophilus) microplus.
abstract: The number of studies emphasizing the possible damage that acaricidal spray formulations can cause on engorged female ticks' reproductive parameters is small. The present study evaluated the deleterious effects of a spray formulation (dichlorvos 60% + chlorpyrifos 20%) on the reproductive parameters of a susceptible population of Rhipicephalus (B.) microplus females, using the Stall Test. The ticks were allocated randomly to treatments according to the mean numbers of females detached from each cow on days -3, -2 and -1 and the cattle pen location. The numbers of engorged female ticks that naturally detached from the cattle were counted daily from day 1 to day 30. For each group, 20 detached engorged female ticks or the available number collected daily were evaluated regarding reproductive parameters. Associations of organophosphates demonstrated elevated acaricidal efficacy, as well as deleterious effects on the reproductive parameters of R. (B.) microplus females. The engorged female weight (days 1 to 7), weight of egg masses (days 5 to 10) and larval hatching percentage (days 5 to 19) were decreased (P ≤ 0.05). It is possible that a formulation can lead to deleterious effects on R. (B.) microplus females when the tick population analyzed shows elevated sensitivity towards a particular formulation. However, further studies need to be conducted.
authors.affiliation: Centro de Pesquisas em Sanidade Animal - CPPAR, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil.
authors.forename: Breno Cayeiro
authors.initials: BC
authors.lastname: Cruz
authors.affiliation: Centro de Pesquisas em Sanidade Animal - CPPAR, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil.
authors.forename: Welber Daniel Zanetti
authors.initials: WD
authors.lastname: Lopes
authors.affiliation: Centro de Pesquisas em Sanidade Animal - CPPAR, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil.
authors.forename: Willian Giquelin
authors.initials: WG
authors.lastname: Maciel
authors.affiliation: Centro de Pesquisas em Sanidade Animal - CPPAR, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Felipelli
authors.affiliation: Centro de Pesquisas em Sanidade Animal - CPPAR, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil.
authors.forename: Weslen Fabricio Pires
authors.initials: WF
authors.lastname: Teixeira
authors.affiliation: Centro de Pesquisas em Sanidade Animal - CPPAR, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil.
authors.forename: Flavia Carolina
authors.initials: FC
authors.lastname: Favero
authors.affiliation: Centro de Pesquisas em Sanidade Animal - CPPAR, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil.
authors.forename: Luciana
authors.initials: L
authors.lastname: Prando
authors.affiliation: Centro de Pesquisas em Sanidade Animal - CPPAR, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil.
authors.forename: Carolina
authors.initials: C
authors.lastname: Buzzulini
authors.affiliation: Centro de Pesquisas em Sanidade Animal - CPPAR, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil.
authors.forename: Vando Edesio
authors.initials: VE
authors.lastname: Sorares
authors.affiliation: Centro de Pesquisas em Sanidade Animal - CPPAR, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil.
authors.forename: Lucas Vinicius Costa
authors.initials: LV
authors.lastname: Gomes
authors.affiliation: Centro de Pesquisas em Sanidade Animal - CPPAR, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil.
authors.forename: Murilo Abud
authors.initials: MA
authors.lastname: Bichuette
authors.affiliation: Centro de Pesquisas em Sanidade Animal - CPPAR, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil.
authors.forename: Alvimar José da
authors.initials: AJ
authors.lastname: Costa
mesh_terms: D056810:Acaricides / Q000494:pharmacology*; D000336:Aerosols; D000818:Animals; D002417:Cattle; D004390:Chlorpyrifos / Q000494:pharmacology*; D004006:Dichlorvos / Q000494:pharmacology*; D005260:Female; D011897:Random Allocation; D012098:Reproduction / Q000187:drug effects; D048494:Rhipicephalus / Q000187:drug effects*
chemical_list: D056810:Acaricides; D000336:Aerosols; D004006:Dichlorvos; D004390:Chlorpyrifos