Banca de DEFESA: TALIA SILVA RIBEIRO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : TALIA SILVA RIBEIRO
DATE: 12/06/2024
TIME: 08:00
LOCAL: https://meet.google.com/mfh-zotf-hdh
TITLE:

Evaluation of the toxicity of essential oils for Sitophilus zeamais control in maize storage

KEY WORDS:

chemical compounds, ecological control, stored grains, vegetable insecticides, storage pests.

PAGES: 65
BIG AREA: Ciências Agrárias
AREA: Engenharia Agrícola
SUBÁREA: Engenharia de Processamento de Produtos Agrícolas
SPECIALTY: Armazenamento de Produtos Agrícolas
SUMMARY:

The corn weevil (Sitophilus zeamais) is one of the main pests of stored grains, causing both quantitative and qualitative losses, particularly in warm and humid regions worldwide. Insect infestation in stored foods has traditionally been managed through chemical control methods. However, the use of these chemicals poses serious risks to the environment, fauna, and human health, potentially leading to lethal effects on non-target organisms and promoting pest resistance. Consequently, there is an increasing demand for alternative methods, such as botanical byproducts with insecticidal properties, to transition towards agroecological production. This study, conducted in a pioneering manner within the identified territory, aims to evaluate the insecticidal potential of essential oils from native species of the Atlantic Forest for controlling S. zeamais in stored maize grains. In Chapter I, an integrative review was conducted on the main chemical components of essential oils that exhibit insecticidal action against the corn weevil. The search was performed across various databases, including Scopus, PubMed, Web of Science, Virtual Health Library, Scielo, Sciencedirect, and Google Scholar, covering articles published between January 2010 and June 2023. A total of 754 articles were identified, with 93 titles selected, highlighting α-pinene, 1,8-cineole, linalool, and limonene as the most prevalent compounds in the studied essential oils. In Chapters II and III, essential oils from Protium heptaphyllum, Piper macedoi, and Schinus terebinthifolius were collected from points in the Extreme South of Bahia, extracted by hydrodistillation, analyzed and characterized by Gas Chromatography, and subjected to contact toxicity and fumigant assays against S. zeamais. The non-sexed insects used were obtained from infected maize obtained from local markets in the Extreme South of Bahia and reared in the laboratory. The mortality rate of adult insects was evaluated at different concentrations of essential oils, through contact exposure after 12, 24, 48, 72, and 96 hours, and through fumigation after 12, 24, and 48 hours. The collected data underwent exploratory analysis for homogeneity and variance normality of treatments, with ANOVA, parametric, and/or non-parametric tests applied. Mortality was determined through Probit analysis. In Chapter II, the essential oil of P. heptaphyllum yielded 9.61%, with limonene (62.26%), α-pinene (16.76%), and o-cymene (8.05%) as the major components. Regarding contact tests, P. heptaphyllum showed low toxicity and demonstrated fumigant potential, achieving a mortality rate of 100% against S. zeamais. In Chapter III, for P. macedoi, the yield was 0.9%, with the main compounds being 1,8-cineole (17.66%), followed by β-pinene (8.22%), αpinene (7.43%), and camphene (5.88%). S. terebinthifolius exhibited a yield of 5.0%, with the main constituents being D-limonene (27.86%), carvone (9.21%), and cis-carveol (6.8%). The tests showed mortality rates of up to 10 to 50% for both species in contact toxicity assessments and up to 100% in fumigation tests for S. terebinthifolius. It is concluded that further bioassays with higher dosages are necessary to determine the appropriate concentration for controlling the corn weevil in stored maize grains.

COMMITTEE MEMBERS:
Presidente - 1906490 - LUANNA CHACARA PIRES
Interna - 1716815 - GISELE LOPES DE OLIVEIRA
Interna - 1197643 - MARCIA NUNES BANDEIRA RONER
Interno - 1322722 - SEBASTIAO RODRIGO FERREIRA
Externa ao Programa - 1156996 - LIVIA SANTOS LIMA LEMOS - UFSBExterna ao Programa - 1149467 - TAINA SORAIA MULLER - UFSB