Banca de DEFESA: WEVERTTON MARLLON ANSELMO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : WEVERTTON MARLLON ANSELMO
DATE: 22/11/2021
TIME: 15:00
LOCAL: Google Meet
TITLE:

Insecticidal activity of essential oils on Sitophilus zeamais MOTS. (COLEOPTERA: CURCULIONIDAE)

KEY WORDS:

Bioinsecticide, Sitophilus zeamais, Essential oils

PAGES: 88
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

Corn (Zea mays L.) is a cereal of traditional economic and social importance. In tropical climatic conditions, insects are particularly important as pests of stored grains, with the insects causing a decrease in nutritional value and a devaluation of the value of the product. The main pests of stored grains are members of the order Coleoptera, especially Sitophilus zeamais (Motschulsky). The present study aimed to evaluate the insecticidal activity of the commercial essential oil of Pothomorphe umbellata and the essential oil of Myrciaria floribunda leaves collected from the germplasm bank of the Federal University of Alagoas. In addition, it aimed to develop a product for the control of S. zeamais. For this, first, the extraction of oil from M. floribunda was performed by hydrodistillation at 160°C for 3h. The essential oil of P. umbellata was purchased at a specialized store. Afterwards, the oils were characterized by gas chromatography and gas chromatography techniques coupled with mass spectrometry. Then, toxicity tests were performed by contact, fumigation, ingestion and activity of digestive enzymes and acetylcholinesterase. The analysis of the chemical composition of the essential oil of
M. floribunda showed that the major components are: E-Caryophyllene (26.81%); Viridiflorol (6.64%) and α - Selinene (3.58%). For the OE of P. umbellatait was identified that its main constituents were: β – Pinene (27.33%), α – Pinene (14.55%) and Linalol (12.03%). The fumigant toxicity test showed that concentrations from 4 μL/L of air were significantly different from the control for the OE of M. floribunda , while for P. umbellata, all concentrations were significantly different from the control, except for the concentration of 2.7 μL/L. For the ingestion test, the results showed that the two oils interfered with nutrition, causing a decrease in insect biomass. In the tests of the effect of digestive enzymes, it is noteworthy that the EO from P. umbellata reduced the amylase activity at the lowest concentrations, however, the EO from M. floribunda increased the enzyme activity at the highest concentrations. As for trypsin, there was no change. Regarding acetylcholinesterase, an increase in its activity was verified in both OE. Thus, we can conclude that the two EOs have important insecticidal activity in the control of S. zeamais, thus contributing to the reduction of problems caused by insect pests in products stored in tropical regions.

BANKING MEMBERS:
Presidente - 2318856 - DANIELA MARIA DO AMARAL FERRAZ NAVARRO
Externo à Instituição - EMMANUEL VIANA PONTUAL - UFRPE
Externa à Instituição - LIDIANE PEREIRA DE ALBUQUERQUE - UFPI
Interna - 1217065 - TERESINHA GONCALVES DA SILVA
Externo ao Programa - 1960817 - THIAGO HENRIQUE NAPOLEAO