Atividade do neonicotinóide dinotefuran sobre Ctenocephalides felis felis (Bouché, 1835) (Siphonaptera: Pulicidae)

Abstract

The purpose of the present study was to evaluate the activity of the neonicotinoid dinotefuran on the cat flea Ctenocephalides felis felis. Fleas used in controlled and in vitro tests were obtained from a colony maintained at Laboratory of Development of Parasiticide Products (LDPP), and the Beagle dogs used for the controlled tests were kept at the same place. Five concentrations of dinotefuran, 0.2085, 0.417, 0.834, 1.668 and 3.336%, were evaluated for in vitro activity on eggs and adults of C. felis felis. Dinotefuran did show low activity on flea eggs, but showed efficacy on adult fleas. Two formulations of dinotefuran were titulated. For spray formulation, 0.834% was selected and for strip-on formulation, 30% was selected. Later, the efficacy of two strip-on formulations, one containing 30% dinotefuran and other with 30% dinotefuran plus 2.575% pyriproxyfen, were evaluated in the control of fleas on dogs. Dogs were infested with 100 adult fleas and evaluated after 48 hours. The efficacy was to 99.5 and 100% for day 1 declining to 76.1 and 72.2% on day 35, respectively. Two spray formulations, one with 0.834% dinotefuran and other with 0.834% dinotefuran plus 0.148% pyriproxyfen, were tested for the control of fleas on dogs. Dogs were infested and evaluated after 48 hours. The efficacy was 100% on day 1 for both formulations, reducing for 66.6% on day 28 and 59.4% on day 35, respectively. Four formulations previously described were tested on naturally infested housed kept-dogs from Seropédica City, RJ. Animals were evaluated weekly. The efficacies were 95.2 on day 7 and 91.4% on day 56 for the spray formulation with dinotefuran; and 100% on day 7 and 88.1% on day 56 for the spray association. For dinotefuran strip-on were 98.5% on day 7 and 74% on day 56; and 100% on day 7 and 81.1% on day 56 for strip-on association. Residual activity of treated dog s hair with dinotefuran on eggs, larvae and adults of fleas were evaluated. One dog was treated with 0.834% dinotefuran spray, other dog was treated with 30% dinotefuran strip-on and the third was not treated. Some areas of dog s hair were clipped on days 2, 16, 23, 30, 37 and 44 after treatment. For the evaluation of adulticidal, larvicidal and ovicidal activities were used adults, larvae and eggs from the laboratory colony. Six repetitions were used with 10 specimens of each flea stage per day, placed in assay tubes. In each repetition were added 0.02 g of treated or untreated dog s hair and larval diet for immature stages. The adulticidal activity was evaluated during 24 hours, the larvae 20 days after treatment and the eggs 72 after challenge. The residue on hair of both treated dogs showed efficacy on the larval control for 44 days and on egg control at day 2. Regarding the adults control the spray and strip-on formulations showed efficacy until days 16 and 23, respectively.