Banca de QUALIFICAÇÃO: MONIQUE TAVEIRA MEDEIROS
Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.STUDENT : MONIQUE TAVEIRA MEDEIROS
DATE: 03/07/2024
TIME: 08:00
LOCAL: Banca híbrida - LQEPV/DPA/IV/UFRRJ + google meet
TITLE:
In vitro activity of different essential oils against Cochliomyia hominivorax larvae.
KEY WORDS:
volatile oil, green chemistry, screwworm
PAGES: 67
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:
Cochliomyia hominivorax is the main blowfly that causes myiasis in the Americas, with great clinical and economic relevance. Currently, in Brazil, control of this dipteran is associated with the use of different classes of insecticides. However, resistance genes to ectoparasiticides are being identified in different populations of these flies, which could become a future problem for their control. Furthermore, the indiscriminate use of insecticides represents a constant unique health concern. In this context, the search for less harmful alternatives, such as the use of essential oils (EOs), has been gaining prominence in research around the world. Based on this, the objective of this work was to evaluate the in vitro insecticidal potential of 15 different EOs against C. hominivorax larvae. In this study, L3 from the C. hominivorax blowfly maintained in a laboratory colony were used. The insecticidal activity of EOs of: Citrus bergamia, C. paradisi, Cinnamomum cassia, Copaifera reticulata, Cymbopogon flexuosus, C. winterianus, Eugenia caryophyllus, Illicium verum, Juniperus virginiana, Lavandula hybrida, Origanum vulgare, Pelargonium graveolans, Rosmarinus offcinalis, Salvia sclarea and Thymus vulgaris and the main constituents: anethole, carvacrol and thymol. The evaluation of biological activity was carried out by contacting L3 with filter paper impregnated with different concentrations of EO. The first step was to determine the insecticidal activity of the 15 EOs by exposing the larvae to a concentration range that varied from 2000 – 200 μg/cm2. For the EOs that presented a mortality rate of 100%, lethal concentrations (CL) 50 and 90 were determined, as well as their majority constituents. The data were tabulated, and the average mortality percentage was calculated for 24 and 48 hours after exposure. Next, LC50 and LC90 were calculated using the RStudio Team® program (2020), with a statistical significance level of p < 0.05 and confidence interval (95% CI). In the first stage, the mortality percentage was equal to 100% for the EOs of I. verum, O. vulgare and T. vulgaris. The EOs of C. bergamia, C. paradisi, C. cassia, C. flexuosus, E. caryophyllus and R. officinalis presented a mortality rate ranging from 30 to 60%. The others had a mortality rate of less than 30%. The LC50 was 417.9 and 559.4 μg/cm2 and the LC90 was 913.9 and 1028.1 μg/cm2 for I. verum EO and anethole, respectively, in the evaluations after 48 hours. For the OE of O. vulgare, the LC50 were 540.9 and 253.71 μg/cm2 and the LC90 were 1819.3 and 1193.9 1 μg/cm2 for evaluations after 24 and 48 hours. For carvacrol, the LC50 was 970.5 and 931.9 μg/cm2 and the LC90 was 1700.2 and 1591.8 μg/cm2 for evaluations after 24 and 48 hours. For the EO of T. vulgaris, the LC50 were 407.1 and 314.8 μg/cm2 and the LC90 were 1149.4 and 589.7 μg/cm2 for evaluations after 24 and 48 hours. For thymol, LC50 were 255.7 and 102.3 μg/cm2 and LC90 were 1008.6 and 690.1 μg/cm2 for evaluations after 24 and 48 hours. Based on the results presented, it is possible to conclude that EOs can be an alternative for the control of C. hominivorax larvae, especially the EOs of I. verum, O. vulgare and T. vulgaris, as well as their majority constituents.
COMMITTEE MEMBERS:
Presidente - 2456316 - KATHERINA COUMENDOUROS
Interno - ***.088.737-** - DIEFREY RIBEIRO CAMPOS - UFRRJ
Interna - 2929889 - THAIS RIBEIRO CORREIA AZEVEDO
Interna - 1700427 - YARA PELUSO CID
Externa ao Programa - ***.630.647-** - BARBARA RAUTA DE AVELAR - UFERSA
Externo à Instituição - ISABELLA VILHENA FREIRE MARTINS