Banca de DEFESA: VICTOR ELIAS CACERES RIOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : VICTOR ELIAS CACERES RIOS
DATE: 31/03/2022
TIME: 14:00
LOCAL: https://us02web.zoom.us/j/88683268150
TITLE:

Activity of Novaluron and Pyriproxyfen on Ctenocephalides felis felis (Siphonaptera, Pulicidae)

KEY WORDS:

flea; control; insect growth disruptors; lethal concentration

PAGES: 58
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

Fleas are among the ectoparasites that most affect companion animals. They produce and transmit diseases that pose a danger to the health of animals and humans. The control of these insects involves the use of insecticides. Insect growth disruptors are a group of insecticides that can act as an alternative in flea control. The objective of this work was to evaluate the activity of novaluron and pyriproxyfen on Ctenocephalides felis felis larvae in in vitro tests during cycle interruption, determining the lethal concentration (LC) of the two compounds. Initially, the larval substrate impregnation method to be used in the experiment was evaluated. For this, a 400 ppm pyriproxyfen solution was prepared and an impregnation volume of 200 µL was used for two grams of substrate. The result was satisfactory, and the methodology did not interfere with the result, with 100% inhibition of the flea development cycle and there was no interference in the development of the cycle for control. To carry out the experiment with the disruptors, the aforementioned methodology was used. Different concentrations of pyriproxyfen (0.049 to 25 ppm) and of novaluron (0.001 to 5.0 ppm) were prepared. After substrate impregnation, the first instar larvae were exposed to the treated larval substrate. The material was kept under controlled conditions for a period of 21 days. Qualitative and quantitative assessments were performed and lethal concentrations were determined through Probit analysis. In the evaluation of the test with pyriproxyfen, an efficiency of 100% was verified in concentrations greater than 1,563 ppm. From the pupae, live and dead fleas were recovered, the dead ones showed changes in morphology, color and size. It was observed that there was a significant difference between the amount of live fleas recovered from the control and treated groups, in addition to a greater number of females compared to males. The calculated lethal concentration LC₅₀ and LC₉₀ of pyriproxyfen was 0.07 and 0.27 ppm, respectively. In the novaluron test there was 100% efficacy at the highest concentration (5.0 ppm). Some dead fleas were recovered from the pupae, they showed changes in the exoskeleton, color and limbs, but without visible changes in size. The amount of live fleas recovered was discontinuous between the concentrations, the control had a significant difference with the treated ones from the concentration 1.0 ppm. Regarding sex, they were mostly females, except in the concentration of 1.75 ppm. The calculated lethal concentration LC₅₀ and LC₉₀ of novaluron were 0.25 and 2.29 ppm, respectively. Based on the results of this work, it can be stated that both pyriproxyfen and novaluron have shown activity on Ctenocephalides felis felis larvae, interrupting the normal developmental cycle of the flea. In addition, novalorun was tested for the first time in a flea laboratory colony in Brazil, proving to be an alternative for the flea control.

BANKING MEMBERS:
Presidente - 2929889 - THAIS RIBEIRO CORREIA AZEVEDO
Interno - 124.088.737-03 - DIEFREY RIBEIRO CAMPOS - UFRRJ
Interno - 1705075 - DOUGLAS SIQUEIRA DE ALMEIDA CHAVES
Interna - 1700427 - YARA PELUSO CID
Externa ao Programa - 057.185.477-00 - VIVIANE DE SOUZA MAGALHAES - UFRRJ
Externo à Instituição - ISABELLA VILHENA FREIRE MARTINS - UFES