Banca de DEFESA: JESSICA KAROLINE DE OLIVEIRA CHAVES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JESSICA KAROLINE DE OLIVEIRA CHAVES
DATE: 26/09/2022
TIME: 14:00
LOCAL: Plataforma Zoom
TITLE:

Evaluation of the in vitro insecticidal and repellent activity of essential oils of plants of Cymbopogon genus and the major constituent geraniol against Ctenocephalides felis felis.

KEY WORDS:

Flea. Biocontrol. citronella. East Indian lemongrass. Palmarosa.

PAGES: 130
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:

The flea Ctenocephalides felis felis is the most prevalent subspecies in domestic animals. The search for natural molecules with less impact on human, animal and environment health to control this ectoparasite has been increasing in recent years, such as the use of essential oils (EO's). The objective of this work was to evaluate the insecticidal, repellent and biological cycle interruption (ICB) activity of the EO's of Cymbopogon nardus (OECN), C. winterianus (OECW), C. flexuosus (OECF) and C. martini (OECM), and of the geraniol component, in addition to determining the lethal concentrations (CL) 50 and 90 and residual efficacy in vitro, against different evolutionary forms of C. felis felis. Chemical composition analysis was performed by Gas Chromatography equipped with a flame ionization detector (FID), and a split/split-less injector to separate and detect essential oil constituents. All specimens came from the LQEPV laboratory flea colony. For the in vitro tests, serial dilutions (1:2) were performed from the highest concentration of EO's, using 20% acetone. For the insecticidal activity, 10 eggs, larvae, pupae and adults were used. Ten eggs were also used to evaluation of ICB and, for the repellency and residual efficacy test, ten adult fleas were used. The immature phases were placed in petri dishes (60 x 15mm) and a filter paper disc (51mm in diameter) impregnated with a certain concentration of the evaluated solution was inserted, while the adults were placed in test tubes (1 x 10cm) and a filter paper strip (1 x 10 cm) impregnated with the same concentrations was inserted. Test control was performed with 20% acetone and the entire test was performed in sextuplicate. The reading of the insecticide test was performed at 72 hours, 24 hours and 15 days for eggs, larvae and pupae, respectively, and for adults, it was performed at 24 and 48 hours. In the ICB assay, the quantification of adults emerged from the puparium was performed 30 days after egg incubation. In the repellency test, the readings occurred at 1, 3, 6, 12, 24 and 48 hours after the challenge. Data were tabulated and LC₅₀ and LC₉₀ values were statistically calculated using Probit analysis, using the IBM SPSS Statistics program with a 95% confidence interval. The major constituents identified were citronellal for OECN and OECW, α-Citral for OECF and geraniol for OECM. Geraniol showed the highest insecticidal activity against eggs (LC50 = 14.7 μg/cm²), pupae (LC50 = 47.1 μg/cm²) and adults (LC50 = 84.6 μg/cm²), while OECM showed it for larvae (LC50 = 19.4 μg/cm²). The EO's and the geraniol showed repellent activity at a concentration of 800 µg/cm², with a greater prolongation of effectiveness demonstrated by the OECM (repellence percentage = 92.9% in 48 hours). OECM and geraniol showed greater residual efficacy (26 days) when compared to the others. In short, it is concluded that the EO's used and geraniol were effective against C. felis felis in all tests performed.

BANKING MEMBERS:
Presidente - 1173660 - FABIO BARBOUR SCOTT
Interna - ***.630.647-** - BARBARA RAUTA DE AVELAR - UFRRJ
Interna - 1700427 - YARA PELUSO CID
Externo à Instituição - LIVIO MARTINS COSTA JUNIOR
Externo à Instituição - ISABELLA VILHENA FREIRE MARTINS - UFES