Banca de DEFESA: MIRIAN CARDINOT DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MIRIAN CARDINOT DA SILVA
DATE: 27/02/2026
TIME: 09:00
LOCAL: Videoconferência
TITLE:

In vitro analysis of the post-embryonic development of Chrysomya albiceps under exposure to commercial neem oil (Azadirachta indica).

 

KEY WORDS:

biopesticide; entomotoxicology; biological parameters; Calliphoridae.

PAGES: 56
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:

The intensive use of synthetic pesticides has been associated with significant environmentalimpacts, including ecosystem contamination, effects on non-target organisms, and the selectionof resistance. In this context, plant-based biopesticides have been adopted as potentially moresustainable alternatives, with neem oil standing out due to its main active compound,azadirachtin, recognized for its regulatory effects on insect growth and development. Althoughwidely used for pest control, further studies are needed to evaluate in detail its effects onbiological parameters in necrophagous dipterans such as Chrysomya albiceps. Und erstand ingpossible alterations in the post-embryonic development of this species is essential to support amore cautious use of the compound, considering both its ecological impacts and its appliedimplications in forensic entomology. This study aimed to evaluate in vitro the post-embryonicdevelopment of Chrysomya albiceps under exposure to commercial neem oil (0.12%azadirachtin). The bioassay was conducted at the Laboratory of Hemoparasites and Vectors ofthe Federal Rural University of Rio d e Janeiro, using newly hatched larvae (L1) distributed intosix experimental groups: negative control, positive control (cypermethrin), and four groupstreated with neem oil at concentrations of 6, 12, 24, and 48 ppm, incorporated into a groundbeef-based diet. Each treatment was performed with five replicates, containing 50 larvae perexperimental unit, maintained at 27 °C, 60% relative humidity, and a 12-hour photophase. Theevaluated parameters included larval mobility, survival, pupation and emergence rates, freshpupal mass, and total development time.Treated larvae showed increased initial mobilitycompared to the control group, with a more intense dispersion pattern and reduced aggregativebehavior. No evidence of acute toxicity was observed at the tested concentrations, as noconsistent increase in mortality was detected in the treated groups. The 6 ppm concentrationshowed a higher emergence rate (83.5%) compared to the control (72.7%). The 12 ppm groupexhibited higher larval mortality (mean of 11.8 individuals) and reduced emergence (64.0%),in addition to a higher mean pupal mass. At 24 and 48 ppm, survival indices remained similarto the control, characterizing a plateau effect. A prolongation of the larval phase and delay inthe developmental cycle were observed in the treated groups, with total duration ranging from10 to 12 days, whereas the control completed the cycle in 9 days. Additionally,
variations inbody size were observed among larvae belonging to the same instar, as well as morphological discrepancies among emerged adults, based on descriptive analysis. Cases of pupation directlyin the feeding substrate were also recorded. The results indicate that, under the evaluatedconditions, neem oil acted as a modulator of development and behavior rather than as a directlethal agent for C. albiceps.

 

COMMITTEE MEMBERS:
Presidente - 3247559 - BRUNA DE AZEVEDO BAETA
Externo ao Programa - 1670591 - LEONARDO SILVESTRE GOMES ROCHA - UFRRJExterna à Instituição - IZABELA MESQUITA ARAÚJO - UFRRJ
Externa à Instituição - JOICE APARECIDA REZENDE VILELA - UFRRJ
Externo à Instituição - RODRIGO GREDILHA DUARTE - UNIRIO