Banca de DEFESA: MARIA RAQUEL DE SOUSA SOARES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MARIA RAQUEL DE SOUSA SOARES
DATE: 25/07/2023
TIME: 09:00
LOCAL: Auditório Fitossanidade
TITLE:

TOXICITY OF MIXED INSECTICIDE FORMULATIONS TO THE POPULATION OF Eriopis connexa (GERMAR) (COLEOPTERA: COCCINELLIDAE) RESISTANT TO PYRETRHOIDS

KEY WORDS:

Selectivity of insecticides, conservation biological control, integrated pest management, neonicotinoids, diamide. 

PAGES: 55
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Entomologia Agrícola
SUMMARY:

Insecticide mixtures ready-to-use offer different modes of action to control pest species, may delay the evolution of resistance, and may reduce costs by reducing the number of applications. However, these formulations can have a negative impact on natural enemies’ populations, depending on the insecticides used in the mixture. In this work, the population of the lady beetle, Eriopis connexa (Germar) was exposed to insecticides in single and mixed formulations with λ-cyhalothrin or chlorantraniliprole. The studied lady beetle population is resistant to pyrethroids (EcViR), hence, exhibiting physiological selectivity when exposed to the non-selective pyrethroid λ-cyhalothrin. The insecticides l-cyhalothrin (Karate Zeon^Ò), chlorantraniliprole (Premio^Ò), sulfoxaflor (Closer^Ò), thiamethoxam (Actara^Ò) and dinotefuran (Dinno^Ò), and their mixtures of λ-cyhalothrin+sulfoxaflor (Expedition^Ò), l-cyhalothrin+chlorantraniliprole (Ampligo^Ò), l-cyhalothrin+dinotefuran (Zeus^Ò), λ-cyhalothrin+thiamethoxam (Engeo^Ò), and chlorantraniliprole+thiamethoxam (Voliam Flex^Ò) were studied. Survival and reproduction were assessed by confining larvae and adults of E. connexa at five and three days old, respectively, with dry insecticide residues. Concentration-mortality curves were also determined for larvae and adults using insecticides in single or mixed formulations that caused mortality greater than 40%. Survival and reproduction of adults surviving the exposure at larva and adult stages were assessed for 30 days. The mixture of λ-cyhalothrin and chlorantraniliprole with thiamethoxam and dinotefuran resulted in the loss of physiological selectivity gained by E. connexa EcViR to λ-cyhalothrin. The combination index, calculated using the estimated LC₅₀, showed a highly antagonistic effect of the neonicotinoids mixed with λ-cyhalothrin and chlorantraniliprole. On the other hand, the mixtures of λ-cyhalothrin+chlorantraniliprole and λ-cyhalothrin+sulfoxaflor allowed the survival of E. connexa EcViR larvae and adults above 80%. Therefore, it was clear that the physiological selectivity gained by the resistance to λ-cyhalothrin in E. connexa is lost when neonicotinoids are present in the insecticide mixture.

COMMITTEE MEMBERS:
Presidente - JORGE BRAZ TORRES
Externo à Instituição - GEMERSON MACHADO DE OLIVEIRA
Externo à Instituição - JOAO PAULO RAMOS DE MELO