Banca de DEFESA: SARA FERREIRA ABUD

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : SARA FERREIRA ABUD
DATE: 23/02/2026
TIME: 09:00
LOCAL: https://meet.google.com/bvh-cnpw-szi
TITLE:

Study of the reproductive biology of Aedes aegypti females after infection with Metarhizium anisopliae

KEY WORDS:

Biological control. Entomopathogenic fungi. Reproduction. Transgenerational effects.

PAGES: 61
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

The mosquito Aedes aegypti (Diptera: Culicidae) is one of the main vectors of medically important arboviruses, requiring sustainable control strategies in light of the limitations of chemical insecticides and the increasing resistance in populations. In this context, entomopathogenic fungi, such as Metarhizium anisopliae, emerge as promising alternatives for the biological management of the vector. This study evaluated the effects of the CG 153 isolate of M. anisopliae on reproductive parameters, survival, and ovarian morphology of female A. aegypti, as well as its transgenerational impacts on the F1 and F2 generations, including groups subjected to re-exposure. Oogenesis in A. aegypti is a central physiological process for reproduction, involving the maturation of oocytes in the ovaries, vitellogenesis, and subsequent oviposition. During the gonotrophic cycle, blood ingestion by females triggers the synthesis of vitellogenin proteins, which are essential for oocyte development. Interference in this process compromises fecundity and embryonic viability, directly affecting the population dynamics of the vector. In the bioassays, oviposition, egg hatching rates, cumulative survival of males and females over 30 days, and ovarian alterations were evaluated by scanning electron microscopy. Exposure to the fungus caused marked reductions in oviposition and egg hatching rates, with more pronounced effects in subsequent generations and re-exposed groups. In F1, oviposition was up to 78.8% lower than in the control, and hatching rates were approximately 2.5 times lower; in F2, oviposition decreased by 88% and hatching rates were 15 times lower. The median survival of treated males decreased by up to 62.5% in F1 and 60% in F2, while females showed reductions of 43.6% and 58%, respectively, evidencing significant transgenerational effects. Scanning electron microscopy revealed progressive morphological alterations in the ovaries, including epithelial disruption, atrophy, reduced oocyte size, and compromised egg viability. These alterations were more pronounced in re-exposed groups, corroborating the oviposition and hatching data. In F3, the low egg hatching in the treated group prevented the continuation of the bioassays, highlighting the cumulative impact of the fungus on vector reproduction. The results indicate that the CG 153 isolate of M. anisopliae directly interferes with oogenesis and oocyte maturation, compromising reproductive capacity and reducing the biological fitness of A. aegypti across generations. The observed transgenerational effect suggests the possible involvement of heritable immune mechanisms and energetic trade-offs between defense and reproduction. This study demonstrates that M. anisopliae acts as a transgenerational modulator of the biological fitness of A. aegypti, promoting progressive reductions in survival, reproductive impairment, and structural ovarian alterations, highlighting the potential of this isolate for biological control and as a complement to integrated vector management strategies

COMMITTEE MEMBERS:
Presidente - 2860277 - ISABELE DA COSTA ANGELO
Interno - 1296670 - WENDELL MARCELO DE SOUZA PERINOTTO
Externo à Instituição - JACENIR REIS DOS SANTOS MALLET
Externa à Instituição - MARIANA GUEDES CAMARGO - UV