Sublethal concentrations of acetylcarvacrol strongly impacts oocyte development of engorged female cattle ticks Rhipicephalus microplus (Canestrini, 1888) (Acari: Ixodidae)

Publication date: Available online 16 March 2019Source: Ticks and Tick-borne DiseasesAuthor(s): I.F.M. Konig, R.R.P. Gonçalves, M.V.S. Oliveira, C.M. Silva, S.S. Thomasi, A.P. Peconick, R.N. RemedioAbstractRhipicephalus microplus, commonly known as southern cattle tick, causes huge economic losses in the cattle industry. Its infestation affects the production of meat and milk and causes discomfort to hosts. In addition, it is the vector of Babesia spp. and Anaplasma spp. The most frequent method used to control these parasites is through synthetic acaricides. However, their indiscriminate use can be toxic for hosts and environment as well as cause selection of resistant ticks. Plant extracts and essential oils emerge as promising alternatives to manage tick infestation. Carvacrol, an aromatic monoterpene extracted from plants, has recognized antimicrobial, antioxidant, insecticidal, repellent and acaricidal activities. Acetylation of carvacrol is believed to enhance its nematicidal and acaricidal activities and to decrease its toxicity to hosts. Thus, the aim of this study was to evaluate the effect of different concentrations of acetylcarvacrol in the morphology of ovaries of engorged R. microplus ticks. The most remarkable morphological alterations found in the female germ cells were irregular and thicker chorion, decreasing in size and irregular shape of female germ cells (oocytes), cytoplasmatic vacuolization as well as ring-shaped nucleoli. These alterations were analyz...
Source: Ticks and Tick borne Diseases - Category: Zoology Source Type: research