Banca de DEFESA: ALYCE ROCHA DE CARVALHO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ALYCE ROCHA DE CARVALHO
DATE: 31/07/2023
TIME: 14:00
LOCAL: Sala do PPGPA
TITLE:

Behavioral responses os Sitophilus zeamais Mots. (COLEOPTERA: CURCULIONIDAE) induced by Caatinga plants hydrolates 

KEY WORDS:

Caatinga, Bioinsecticides, Behavioral Effects.

PAGES: 60
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Entomologia Agrícola
SUMMARY:

The weevil Sitophilus zeamais Mots. (Coleoptera: Curculionidae) is considered one of the main insects that affect stored corn grains and seeds, generating significant economic losses. The main control method used for management is the use of synthetic chemical insecticides that can cause damage to the environment and to human and animal health. In view of this, the use of endemic bioactive plant extracts has been highlighted for its low cost, insecticidal, repellent, feeding inhibitor and growth regulator effect. Thus, the objective of this work was to investigate the chemical composition of hydrolates from Tinguí (Serjania cf. lethalis A.St.-Hil.), Bálsamo (Myroxylon peruiferum L.f.), Alecrim da Caatinga (Lippia origanoides Kunth) and Sacatinga-branca (Croton heliotropiifolius Kunth), to evaluate the fumigant effect, contact and ingestion and behavioral effect on populations of Sitophilus zeamais. To obtain the essential oil, leaves of plant species in the Caatinga biome region, Pernambuco, Brazil, were collected, dehydrated, crushed and subjected to the hydrodistillation process in a Clevenger-type apparatus. The chemical characterization of the oil was performed in a gas chromatograph coupled to a mass and headspace spectrometer. To verify the fumigant effect, the concentrations (0.00; 0.0001; 0.0003; 0.0004; 0.0006; 0.0007; 0.0014; 0.0028; 0.0042; 0.0056; 0. 0069; 0.0139; 0.0278; 0.0417; 0.0556; 0.0694 μL/L of air) of the hydrolates were pipetted onto filter paper (5x2 cm) attached to the underside of the fumigation chamber lid, in the which contained 10 grams of untreated maize and 10 unsexed adults of S. zeamais. Insect mortality was evaluated after 48 hours of exposure. For the contact and ingestion bioassay, the hydrolate concentrations (0.00; 0.0028; 0.0056; 0.0083; 0.0111; 0.0139; 0.0278; 0.0556; 0.0833; 0.1111; 0.1389; 0.2778; 0.5556; 0.8333; 1.1111 and 1.3889μl/g) were pipetted into Petri dishes (90x15 mm) containing 20 grams of corn and manually shaken for two minutes. They were then infested with 10 unsexed adults of S. zeamais. Insect mortality was evaluated after 72 hours of exposure. The hydrosols presented different amounts and composition, being the marjoritates: 2-Hexenal, (E)- (49.42%), Methylal (32.77%), 1H-Pyrrole, 1-methyl- (32.47%) and Eucalyptol (14.44%). The results obtained in the mortality tests were submitted to mean tests, and those of behavior, Tukey's test (p ≤ 0.05) and (p ≤ 0.01), using the statistical program Sisvar, version 5.6. In the fumigant test, from the concentration of 0.0278 to 0.0695 μl L-1 of air, caused mortality ranging from 3 to 18%. In the contact and ingestion test, the average mortality was 3% ± 1.9, the highest percentage of mortality occurred between the concentrations 1.11 and 1.389 μl/g of corn grains treated with Bálsamo hydrolate (M. peruiferum) with 7.5% and 12.5%, respectively, and for the other concentrations used, it is possible to state that the insecticidal activity is low. When tested using a four-way olfactometer, they showed a repellent effect at concentrations of 0.1 and 10% S. lethalis, 0.01% M. peruiferum, 0.1% L. origanoides and 0.001% C. heliotropiifolius under S. zeamais. Thus, it is suggested that new studies be carried out, involving the other stages of development of S. zeamais with other concentrations of the compounds.

COMMITTEE MEMBERS:
Interno - CESAR AUGUSTE BADJI
Externo à Instituição - JOAO PAULO RAMOS DE MELO
Externa à Instituição - MARIANA OLIVEIRA BREDA - UFAL