Banca de DEFESA: JOANA DA ROCHA MATOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JOANA DA ROCHA MATOS
DATE: 20/02/2025
TIME: 09:00
LOCAL: UFRRJ, IV, DPA, Sala 14
TITLE:

Development of an oily formulation based on Cordyceps javanica to control the tick Rhipicephalus microplus in semi-field conditions.

KEY WORDS:

entomopathogenic fungi, biological control, formulation

PAGES: 56
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:

Rhipicephalus microplus, commonly known as cattle tick, is responsible for significant health and economic challenges, particularly in livestock farming, affecting productivity, increasing farm costs and saving animal welfare. Synthetic acaricides, when used economically, can select for resistant tick situations, leading to the need for integrative alternative solutions. Mycoacaricides offer a promising approach in biological control of ticks. The most trained entomopathogenic fungi for tick control are Beauveria spp. and Metarhizium spp., while Cordyceps species are less explored. The present study aimed to assess the effect of a corn oil formulation based on Cordyceps javanica to control the non-parasitic stages of cattle tick under semi-field conditions. Compatibility tests were performed with C. javanica in different concentrations of corn oil (1, 3 or 5%) and oil silicone (0.01%), the vegetable oil was removed using Solub'Oil®, as germination analyses were performed after 24h and 48h after inoculation in PDA. Laboratory tests were extended with C. javanica formulations topically in larvae and females of R. microplus. The formulation 10⁸ conidia/mL + 3% was selected for the test in semi-field conditions, with three collections being performed for persistence analysis before, 24h and 30 days after treatment, with larval recovery in the pots treated with the formulation reduced by 89% compared to the aqueous control group. The persistence of C. javanica conidia in the treated soil was evaluated one and 30 days after treatment. Germination of C. javanica conidia with oil-in-water formulations was higher than 98% after 24 h, and the highest oil concentrations did not inhibit fungal growth. R. microplus larvae treated under laboratory conditions with 10⁸ conidia/mL + 5% corn oil and oil silicone showed 95.17% mortality five days after treatment. Engorged females exposed to the same conditions experienced a 72.5% reduction in egg mass weight compared to the control. Similar results were presented in formulations with 3% corn oil. Even after 30 days of treatment, soil samples from pots treated with C. javanica showed fungal colonies, evidencing the persistence of the fungus in the soil. Our study supports the integration of oily plant mycoacaricides as part of an integrated management strategy, offering a more sustainable solution that reduces chemical dependence in livestock farming. The successful use of C. javanica as a biological control agent can therefore improve animal health, promote food security and contribute to the sustainability of livestock farming systems.

COMMITTEE MEMBERS:
Presidente - 387922 - VANIA RITA ELIAS PINHEIRO BITTENCOURT
Interna - 3103528 - CLAUDIA BEZERRA DA SILVA
Interna - 2860277 - ISABELE DA COSTA ANGELO
Externo à Instituição - ALLAN FELIPE MARCIANO
Externo à Instituição - CAIO MÁRCIO DE OLIVEIRA MONTEIRO - UFG