EVALUATION OF THE ACTION OF FIPRONIL ON ENGORGED FEMALES OF RHIPICEPHALUS SANGUINEUS SENSU LATO.

Roxanne Marina Da silva Roque; Barbara Rauta de Avelar; Manuela Pimentel da Motta; Brena Gava Guimarães; Isabella Souza Da Silva; Lais Sperandio Cassani; Lumara Vidal Martins; Ygor Henrique da Silva; Fabio Scott

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Trabalho

Título do Trabalho

EVALUATION OF THE ACTION OF FIPRONIL ON ENGORGED FEMALES OF RHIPICEPHALUS SANGUINEUS SENSU LATO.

Autores

Roxanne Marina Da silva Roque
Barbara Rauta de Avelar
Manuela Pimentel da Motta
Brena Gava Guimarães
Isabella Souza Da Silva
Lais Sperandio Cassani
Lumara Vidal Martins
Ygor Henrique da Silva
Fabio Scott

Modalidade

Resumo

Área temática

Ectoparasitos: sistemática, epidemiologia e controle

Data de Publicação

10/03/2025

País da Publicação

Brasil

Idioma da Publicação

Inglês

Página do Trabalho

https://www.even3.com.br/anais/ix-simposio-internacional-em-ciencias-veterinarias-sincvet-ix-international-symposium-in-veterinary-sciences-isvs-499466/1032804-evaluation-of-the-action-of-fipronil-on-engorged-females-of-rhipicephalus-sanguineus-sensu-lato

ISBN

978-65-272-1246-1

Palavras-Chave

control, in vitro test, tick.

Resumo

Rhipicephalus sanguineus sensu lato, known as the brown dog tick, is an ectoparasite widely distributed throughout the world, especially in tropical and subtropical regions. Its main hosts are domestic dogs. It is a species of great veterinary importance, since it acts as a vector for various pathogens, including bacteria of the Ehrlichia genus and protozoa such as Babesia canis, which cause serious diseases in dogs. The most common control of tick populations is still carried out using chemical acaricides. Like the fipronil a pesticide from the phenylpyrazole chemical group, used to combat both mites and ticks. This highly active molecule affects the central nervous system (CNS) of invertebrate animals, interfering with the passage of chloride ions via the neurotransmitter GABA. This interference causes the CNS to go haywire, resulting in overexcitation, and eventually death of the organism. The aim of this study was to evaluate the action of fipronil on engorged females of R. sanguineus s.l.. The assays were performed in the Laboratory of Experimental Chemotherapy in Veterinary Parasitology of UFRRJ. For the tests, a 2% mother solution of fipronil was initially prepared from 0.100 mg of the active ingredient diluted in 40% DMSO, 12.5% acetone, 2% Triton X-100 and a\ sufficient quantity of N-methylpyrrolidone to complete 100%. We evaluated the pre-laying period, reproductive efficiency and nutritional index of engorged females at the following concentrations: 1.561, 3.125, 6.25, 12.5, 25, 50, 100, 200, 400 and 800 ppm, obtained from dilution of the stock solution in water, and diluents alone were used as control. The females, detached from rabbits after seven days of feeding (CEUA/IV/UFRRJ n° 9812271021), were immersed in 10 ml the above-mentioned solutions for five minutes. After immersion, they were dried and individually fixed by the dorsal region in Petri dishes and kept in air-conditioned chambers at 27 ºC and 80% relative humidity and they were evaluated daily until the onset of oviposition. Twenty-one days after the females were incubated the mass of eggs produced was weighed and stored in 3 ml syringes adapted for another 21 days under the same temperature and humidity conditions, to evaluate the hatching percentage. Reproductive efficiency (RE) was calculated taking into account the weight of the females, the weight of the eggs and the hatching rate. The reproductive inhibition efficacy (RIE) was then determined by comparing the treated groups with the control group. The nutritional index (NI), which reflects feed conversion capacity, was calculated based on the initial and final weight of the females and egg mass weight. Statistical analysis was performed with Bioestat 5.3. Initially, the distribution of data was verified using the Shapiro-Wilk test. Since the data had nonparametric distribution, the groups were compared using the Kruskal-Wallis test. All tests were performed with a 95% confidence interval (p<0.05). There was significant interference in the pre-oviposition period at concentrations of 25, 100 and 200 ppm. The weight of the egg mass, the hatching rate and RE decreased progressively as the concentration of the compound increased. Significant differences were observed in the eggs masses from 12.5 ppm, while at concentrations of 400 and 800 ppm, the females did not lay eggs. From the concentration of 6.25 ppm onwards, there was a statistical difference in RE, the weight of females at the end of laying and the NI. At the highest concentrations, RE was zero, and EIR reached 100%, indicating total inhibition of reproduction. From the data obtained we can conclude that fipronil had a significant inhibitory effect on the reproduction and food conversion of engorged females of R.sanguineus s.l.

Título do Evento: IX Simpósio Internacional em Ciências Veterinárias (SINCVET) / IX International Symposium in Veterinary Sciences (ISVS)
Título dos Anais do Evento: Anais do IX Simpósio Internacional em Ciências Veterinárias (SINCVET) / IX International Symposium in Veterinary Sciences (ISVS)
Nome da Editora: Even3
Meio de Divulgação: Meio Digital

Como citar

ROQUE, Roxanne Marina Da silva et al.. EVALUATION OF THE ACTION OF FIPRONIL ON ENGORGED FEMALES OF RHIPICEPHALUS SANGUINEUS SENSU LATO... In: Anais do IX Simpósio Internacional em Ciências Veterinárias (SINCVET) / IX International Symposium in Veterinary Sciences (ISVS). Anais...Seropédica(RJ) UFRRJ, 2025. Disponível em: https//www.even3.com.br/anais/ix-simposio-internacional-em-ciencias-veterinarias-sincvet-ix-international-symposium-in-veterinary-sciences-isvs-499466/1032804-EVALUATION-OF-THE-ACTION-OF-FIPRONIL-ON-ENGORGED-FEMALES-OF-RHIPICEPHALUS-SANGUINEUS-SENSU-LATO. Acesso em: 16/07/2025