Sublethal concentrations of acetylcarvacrol affect reproduction and integument morphology in the brown dog tick Rhipicep
- PDF / 1,055,573 Bytes
- 15 Pages / 439.37 x 666.142 pts Page_size
- 75 Downloads / 170 Views
Sublethal concentrations of acetylcarvacrol affect reproduction and integument morphology in the brown dog tick Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) Marcos Vinícius Silva de Oliveira1 · Isaac Filipe Moreira Konig2 · Aline Chaves Reis1 · Larissa Silva3 · Ana Paula Peconick2 · Sérgio Scherrer Thomasi3 · José Ribamar Lima‑De‑Souza5 · Maria Izabel Camargo‑Mathias4 · Rafael Neodini Remedio1 Received: 20 March 2020 / Accepted: 21 August 2020 © Springer Nature Switzerland AG 2020
Abstract Rhipicephalus sanguineus sensu lato (s.l.), also known as the brown dog tick, is among the main tick species involved in the transmission of pathogens to humans and other animals and, therefore, the target of numerous control methods. However, due to the disadvantages of synthetic acaricides, the use of alternative products such as plant derivatives has been encouraged. This study aimed to evaluate the acaricidal potential of acetylcarvacrol and to determine its efficacy at sublethal doses for the control of R. sanguineus s.l. female ticks. In addition, as acetylcarvacrol was applied topically, morphological alterations in the integument were assessed. Acetylation of carvacrol was performed by reaction with acetic anhydride in a sodium hydroxide solution, being confirmed by infrared spectroscopy. The lethal concentration for 50 and 90% ( LC50 and LC90) of unfed ticks and the efficacy of acetylcarvacrol in engorged females were determined after the Adult Immersion Test (AIT). For the evaluation of effects of acetylcarvacrol in the integument, routine histological techniques were employed after the AIT. The LC50 and LC90 in unfed females were 2.8 and 7.2 μL/mL, respectively. Regarding reproductive performance, after treatment with 8.0 μL/ mL acetylcarvacrol 90.9% control was achieved, as ticks showed the lowest egg production index (EPI), hatching rate (HR), and fecundity rate (FR). In the integument, considerable morphological alterations were observed both in cuticle and epithelium. Thus, acetylcarvacrol affected R. sanguineus s.l. external coating and reproduction when applied at sublethal concentrations, probably contributing to a long-term control.
* Rafael Neodini Remedio [email protected] 1
Department of Health Sciences, Federal University of Lavras (UFLA), Av. Dr. Sylvio Menicucci 1001, Lavras, MG 37.200‑900, Brazil
2
Department of Veterinary Medicine, Federal University of Lavras (UFLA), Lavras, MG, Brazil
3
Department of Chemistry, Federal University of Lavras (UFLA), Lavras, MG, Brazil
4
Department of Biology, São Paulo State University (UNESP), Rio Claro, SP, Brazil
5
Department of Natural Sciences, Federal University of Acre (UFAC), Rio Branco, AC, Brazil
13
Vol.:(0123456789)
Experimental and Applied Acarology
Keywords Control · Acaricide · Reproductive fitness · Alloscutum · Carvacrol
Introduction The brown dog tick, Rhipicephalus sanguineus sensu lato (s.l.) (Acari: Ixodidae), is a widely distributed tick species that is able to transmit numerous pathogens to humans and dogs
Data Loading...
