Banca de DEFESA: CATIANE OLIVEIRA SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : CATIANE OLIVEIRA SOUZA
DATE: 24/02/2026
TIME: 08:00
LOCAL: Auditório do PRPG
TITLE:

IMMUNOPHYSIOLOGICAL AND NUTRITIONAL RESPONSES IN Aedes aegypti LINNAEUS (DIPTERA: CULICIDAE) MOSQUITOES EXPOSED TO THE COMPOUNDS TRANS-ANETHOLE, LINALOOL, AND THEIR COMBINATION

KEY WORDS:

Vector, phytochemicals, synergism, bioinsecticides, histology, histochemistry, midgut, immune system

PAGES: 86
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Entomologia Agrícola
SUMMARY:

Aedes aegypti (Linnaeus) represents a major public health threat, as it is the primary vector of arboviruses. Its control relies mainly on the use of synthetic pesticides, which cause environmental damage, are costly, and favor the development of resistance. Therefore, the investigation of natural insecticides derived from plant compounds is necessary for the development of effective products. Although terpenes and phenylpropanoids are abundant constituents of essential oils, their effects on the digestive and immune systems of insects remain poorly understood. Thus, this study aimed to evaluate trans-anethole (a phenylpropanoid) and linalool (a terpene) as larvicidal agents, applied individually and as a binary mixture. In larvicidal bioassays, the median lethal concentrations (LC₅₀) were determined for trans-anethole (68.41 ppm), linalool (240.57 ppm), and the binary mixture (96.43 ppm). To assess immune responses, fourth-instar (L4) larvae exposed to the LC₅₀ values were analyzed for oxidative stress, phenoloxidase activity, melanization, nitric oxide levels, reduced glutathione (GSH), and macromolecule content (proteins, lipids, sugars, and glycogen). Histological, histochemical, apoptosis, and PCNA analyses of the larval midgut were also performed. Trans-anethole and the binary mixture exhibited high toxicity, with particular emphasis on the mixture, which intensified melanization and other immune responses in the larvae and negatively affected their nutritional reserves and cellular homeostasis, suggesting that prolonged exposure may compromise Ae. aegypti survival. All treatments induced oxidative stress, with linalool showing a low antioxidant response mediated by GSH. Only linalool and the binary mixture altered protein and carbohydrate levels in the midgut. All treatments caused morphological pathologies in epithelial cells and induced apoptosis, without evidence of cellular regeneration, indicating that this organ is a major target of acute toxicity. Finally, the compounds and their mixture can be considered promising active ingredients for the development of effective and sustainable biolarvicides.

COMMITTEE MEMBERS:
Interno - EMMANUEL VIANA PONTUAL
Interna - VALERIA WANDERLEY TEIXEIRA
Externo à Instituição - Júlio César R. de O. F. de Aguiar - UFPE
Externa à Instituição - Daniela Maria do Amaral Ferraz Navarro - UFPE
Externa à Instituição - GLAUCILANE DOS SANTOS CRUZ - UFRPE