title: Effect of new ethyl and methyl carbamates on Rhipicephalus microplus larvae and adult ticks resistant to conventional ixodicides.
abstract: The effects of six new synthetic carbamates on fully engorged females of four Rhipicephalus microplus strains (one reference strain susceptible to conventional ixodicides, two strains multiresistant to ixodicides and one tick field isolate) were compared. In addition, the effect of two other new synthetic carbamates was tested on larvae from the same strains. The first six tested carbamates reduced egg laying and inhibited egg hatching in the four studied strains (P<0.05). Compared with untreated females, the eggs produced by the treated engorged female ticks of all strains had a dark, dry, opaque appearance and were less adherent. The remaining two tested carbamates induced larval mortality in all of the evaluated strains. The three studied R. microplus strains displayed 50% resistance ratios (RR50) of less than 2 when compared to the susceptible reference strain. These results demonstrate that both carbamates with a larvicidal effect and carbamates that inhibit egg laying and embryo development are efficacious against tick strains that are resistant to commercial ixodicides, no cross resistance was observed.
authors: Programa de Maestría y Doctorado en Ciencias de la Producción y de la Salud Animal, Universidad Nacional Autónoma de México, Mexico.
authors: I E
authors: IE
authors: Pérez-González
authors: Programa de Maestría y Doctorado en Ciencias de la Producción y de la Salud Animal, Universidad Nacional Autónoma de México, Mexico.
authors: M G
authors: MG
authors: Prado-Ochoa
authors: Departamento de Ciencias Biológicas, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Mexico.
authors: M A
authors: MA
authors: Muñoz-Guzmán
authors: Laboratorio de Química Medicinal, Departamento de Ciencias Químicas, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Mexico.
authors: V H
authors: VH
authors: Vázquez-Valadez
authors: Laboratorio de Química Medicinal, Departamento de Ciencias Químicas, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Mexico.
authors: A M
authors: AM
authors: Velázquez-Sánchez
authors: Laboratorio de Química Medicinal, Departamento de Ciencias Químicas, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Mexico.
authors: B L
authors: BL
authors: Avila-Suárez
authors: Departamento de Ciencias Biológicas, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Mexico.
authors: C
authors: C
authors: Cuenca-Verde
authors: Laboratorio de Química Medicinal, Departamento de Ciencias Químicas, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Mexico.
authors: E
authors: E
authors: Angeles
authors: Departamento de Ciencias Biológicas, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Mexico. Electronic address: fealba@hotmail.com.
authors: F
authors: F
authors: Alba-Hurtado
mesh_terms: D056810:Acaricides / Q000494:pharmacology*; D000818:Animals; D002219:Carbamates / Q000494:pharmacology*; D004351:Drug Resistance / Q000187:drug effects; D005260:Female; D007814:Larva / Q000187:drug effects; D010058:Oviposition / Q000187:drug effects; D048494:Rhipicephalus / Q000187:drug effects*; D014520:Urethane / Q000494:pharmacology*; D015053:Zygote / Q000187:drug effects
chemical_list: D056810:Acaricides; D002219:Carbamates; D014520:Urethane; C036868:methyl carbamate
keywords: Carbamates; Drug resistance; Ixodicides; Rhipicephalus; Ticks