Banca de DEFESA: FELLIPE MATHEUS SOUZA DA COSTA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : FELLIPE MATHEUS SOUZA DA COSTA
DATE: 24/02/2026
TIME: 09:30
LOCAL: Sala 14, auditório do PSA
TITLE:

EFFECT OF ESSENTIAL OILS OF ORIGANUM VULGARE (L.) AND THYMUS VULGARIS (L.), MAJOR COMPOUNDS AND EMULSIFIABLE CONCENTRATE ON STOMOXYS CALCITRANS, THE STABLE FLY.

KEY WORDS:

livestock activity, ectoparasite, mechanical vector, essential oil

PAGES: 69
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

Stomoxys calcitrans, the stable fly, is an obligate hematophagous insect, and both sexes feed on blood for survival and reproduction. It is an ectoparasite of veterinary and economic importance and, due to its painful bite and its role as a mechanical vector of several pathogens, it causes stress, diseases, and significant economic losses to the meat and dairy industries. This scenario is directly associated with residues from the sugarcane industry and excessive organic material such as poultry and cattle manure. Control of this species is mainly based on the use of synthetic insecticides, which continuous and ineffective use has favored the emergence of resistant individuals, in addition to causing environmental impacts and risks to human and animal health. Therefore, natural compounds derived from essential oils, such as Origanum vulgare L. and Thymus vulgaris L., as well as their major compounds carvacrol and thymol, have shown promise as alternatives due to their ectoparasiticidal activities in the current scientific literature. In the present study, a topical application test was performed on adult S. calcitrans, analyzing the longevity and mortality of males and females, and calculating the LD₅₀ and LD₉₀ of each compound. The LD₅₀ values were 4424.65 ppm for O. vulgare L. and 32178.12 ppm for T. vulgaris L. after 24 hours. Their respective major compounds showed LD₅₀ values of 65575.63 ppm for carvacrol and 1823.61 ppm for thymol. In addition, these compounds promoted behavioral alterations associated with impairment of the nervous system. The influence of the compounds on reproductive parameters, such as oviposition, pupation, and adult emergence, was also analyzed. The safety of oregano and thyme essential oils, as well as carvacrol and thymol, was evaluated through cytotoxicity tests on mammalian cells, with thymol being the safest compound after 48 hours of treatment. For this reason, and because it presented the best LD50 and LD90 results, causing the highest mortality rate in adults within 24 hours, thymol was selected for formulation in this study. An EC (emulsifiable concentrate) formulation was developed, and its stability and pH were monitored as validation tests for the formulation. As future perspectives, the thymol-based formulation may and should be tested in outbreak scenarios of S. calcitrans, both in the environment and during adult infestations on animals, to be considered as a potential new bioinsecticide.

COMMITTEE MEMBERS:
Presidente - 1792175 - PATRICIA FAMPA NEGREIROS LIMA
Interna - 1222756 - DEBORA DECOTE RICARDO DE LIMA
Interna - 2929889 - THAIS RIBEIRO CORREIA AZEVEDO
Externo à Instituição - ANTONIO THADEU MEDEIROS DE BARROS - EMBRAPA
Externo à Instituição - FERNANDO GENTA