Evaluation of cytotoxic effects of fipronil on ovaries of semi-engorged Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) tick female

Action of the chemical agent fipronil (active ingredient of acaricide Frontline®) on the liver of mice: An ultrastructural analysis

“…In this direction, the use of these products on target organisms has been proved to be efficient (Oliveira et al, 2008Pereira et al, 2009); however, little is known about their effects on nontarget organisms or on the environment (Hurley et al, 1998;Oliveira, 2010;Tang et al, 2004).…”

“…In addition, it has been used in public health to control the main vectors of anthropozoonosis, such as larvae of the dengue fever mosquito Aedes aegypti (Ali et al, 1998;Pridgeon et al, 2008). Its use has been increasing in global scale in the veterinary medicine, mainly due to its efficiency in the control of fleas and ticks that infest domestic dogs and cats (Frontline 1 e Top Spot 1 ) (Oliveira et al, 2008;Postal et al, 1995). However, the wide utilization of fipronil has directly or indirectly affected not only the target organisms, but also the so-called ''nontarget'' organisms, such as algae, aquatic plants, fishes, amphibians, reptiles, birds, mammals, and the human being (Tingle et al, 2000(Tingle et al, , 2003.…”

Comparative Results of Action of Natural and Synthetic Acaricides in Reproductive and Salivar Systems of Rhipicephalus sanguineus - Searching by a Sustainable Ticks Control

“…Schematics drawing of the histological alterations observed in oocytes (I to V) of Rhipicephalus sanguineus treated with fipronil in different concentrations (control group, 1 ppm, 5 ppm, 10 ppm). ch= chorium; gv= germ vesicle; I= oocyte stage I; II= oocyte stage II; III= oocyte stage III; IV= oocyte stage IV; V= oocyte stage V; nu= nucleolus; pm = plasmic membrane; v=vacuoles; yg= yolk granules (Oliveira et al, 2008).…”

“…Fipronil substance that acts inhibiting the development of ticks in pets animals (Taylor, 2001) and as a neurotoxic substance (Cole et al, 1993) also acts in the reproductive process of the ticks by altering both the structure and function of germinative cells of R. sanguineus (Oliveira et al, 2008). In these individuals ovaries the same authors detected alterations related with the size and morphology of the oocytes as well as presence of vacuoles in the cytoplasm and oocytes that had problem to succeeded in arriving at stage V (mature one), some of them had ruptured or withered, and had released their contents before the end of maturation.…”

Determination of LC50 and LC95 values of fipronil against Haemaphysalis bispinosa based on adult immersion test

“…Previously, Oliveira et al 2008 reported LC 50 of 10 ppm against Rhipicephalus sangunieus. Also, LC 50 and LC 99.9 values of fipronil against susceptible strain of Rhipicephauls (Boophilus) microplus were determined as 0.75 and 2.49 ppm, respectively using AIT (Castro-Janer et al Adult immersion test is more reliable for diagnosis of resistance against fipronil compared to other tests like larval packet test (Castro-Janer et al 2009).…”