title: Cross-resistance between fipronil and lindane in Rhipicephalus (Boophilus) microplus.
abstract: The southern cattle tick, Rhipicephalus (Boophilus) microplus (Canestrini), is one of the most damaging parasites of cattle in tropical and subtropical regions. Several chemical groups have been used for its control, including cyclodienes (lindane and dieldrin). In Uruguay and Brazil these products were used at the beginning of the 1960s and during a few years. Fipronil and lindane act on the same target site. In both countries, southern cattle tick resistance to fipronil has sometimes developed quickly after only a few acaricide treatments (three to seven). The objective of the present study was to determine cross-resistance between fipronil and lindane in southern cattle ticks from Uruguay and Brazil. Initially, the FAO's (Food and Agricultural Organization) larval packet test with lindane was applied to a fipronil-resistant strain and to susceptible field populations. Mozo and POA strains were used as the susceptible controls. A larval immersion test was used to assess fipronil toxicity. Of fifteen fipronil-resistant field populations that were tested with lindane, eleven were lindane-resistant and three were susceptible. The last three populations had incipient resistance to fipronil. Finally, cross-resistance between fipronil and lindane in the southern cattle tick is reported in this study for the first time.
authors: Department of Parasitology, School of Veterinary-UDELAR, Av. Lasplaces 1620, CP 1600, Montevideo, Uruguay; Department of Parasitology, Instituto de Ciências Biomédicas-USP, Av. Prof. Lineu Prestes 1374, CEP 05508000, São Paulo, SP, Brazil. Electronic address: elinor@adinet.com.uy.
authors: E
authors: E
authors: Castro Janer
authors: Laboratory of Parasitology, FEPAGRO Animal Health, Eldorado do Sul, RS, Brazil.
authors: G M
authors: GM
authors: Klafke
authors: Department of Parasitology, Instituto de Ciências Biomédicas-USP, Av. Prof. Lineu Prestes 1374, CEP 05508000, São Paulo, SP, Brazil.
authors: M L
authors: ML
authors: Capurro
authors: Department of Parasitology, Instituto de Ciências Biomédicas-USP, Av. Prof. Lineu Prestes 1374, CEP 05508000, São Paulo, SP, Brazil.
authors: T T S
authors: TT
authors: Schumaker
mesh_terms: D000818:Animals; D001556:Hexachlorocyclohexane / Q000494:pharmacology*; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D011720:Pyrazoles / Q000494:pharmacology*; D048494:Rhipicephalus / Q000187:drug effects*
chemical_list: D007306:Insecticides; D011720:Pyrazoles; D001556:Hexachlorocyclohexane; C082360:fipronil
keywords: Fipronil; Lindane; Resistance; Rhipicephalus (Boophilus) microplus