Banca de DEFESA: CAMILA DA SILVA BARBOSA PEREIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : CAMILA DA SILVA BARBOSA PEREIRA
DATE: 15/12/2023
TIME: 13:00
LOCAL: Auditório da biblioteca/ UFRRJ
TITLE:

Physiological and biochemical aspects of Alphitobius diaperinus (Panzer, 1797) (Coleoptera: Tenebrionidae) and botanical control with lemongrass essential oil (Cymbopogon citratus (DC) Stapf.)

KEY WORDS:

Biological activity, insect biochemistry, mealworms, lemongrass

PAGES: 90
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUMMARY:

The mealworm (Alphitobius diaperinus) is an opportunistic insect pest widely dispersed throughout the world (cosmopolitan), poultry farms where they proliferate as a result of favorable conditions, such as heat, humidity and availability of food (bird feed). In this context, the present study sought to understand some of the biological aspects of A. diaperinus and the effect of Cymbopongon citratus (lemongrass) essential oil on the stages of the insect's reproductive cycle, in addition to investigating the effects of lemongrass essential oil on aspects of mealworm metabolism. For this purpose, biological tests were carried out to observe the development of the mealworm under normal conditions and under the effect of essential oil in the larva, pupa and adult stages. Gravimetric, image and metabolic profile analyzes were used to verify aspects of the insect's biology, physiology and metabolism. After analyzing the insect's reproductive cycle, the female pupae were longer than the males. When adults, their lengths varied between 0.55 and 0.70 cm, with no difference between the sexes. In the larval stages, their weight increased. with its growth, in the last larval stage (L6) its weight did not differ from that of pupae and adults. With this, the exposure of mealworms to lemongrass essential oil by fumigation was also evaluated. It was observed that the toxicity is greater in the adult phase with LC_50% of 0.23 mg/cm³ of air. Phases L3 and L6 presented LC_50% of 1.25 and 1.8 mg/cm³ of air, respectively. It was also found that after 48 hours of exposure to essential oils at concentrations of 1.0 and 2.0 mg/cm³ of air, half of the adult insects were dead. In turn, half of the larvae population (L3) were dead after exposure for 72 hours at a dose of 5.0 mg/cm³ of air and half of the larvae (L6) after 48 hours. There were no effects of lemongrass essential oil on the insect's reproductive cycle when incorporated into food or sprayed on the breeding box. The evaluation of the metabolic profile of insects in the adult and larval stages (L3 and L6) made it possible to verify metabolites such as sugars, organic acids, amino acids, among others. In the control group, a reduction in amino acids was observed and in insects exposed to the essential oil, an increase in amino acids, glycerol and variation in sugar concentrations was observed. Based on the studies carried out, it is concluded that lemongrass essential oil has a toxic effect on insects in very high concentrations, making its use unfeasible as an alternative method for controlling insects.

COMMITTEE MEMBERS:
Presidente - 2582213 - MARCO ANDRE ALVES DE SOUZA
Interna - 3145590 - DANIELA COSENTINO GOMES
Interna - 1177598 - ROSANE NORA CASTRO
Externo à Instituição - Flavio Jose da Silva Dantas - UERJ
Externa à Instituição - LILIA APARECIDA SALGADO DE MORAIS - EMBRAPA