Banca de DEFESA: KAROLAYNE LOPES CAMPOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : KAROLAYNE LOPES CAMPOS
DATE: 26/02/2026
TIME: 14:00
LOCAL: Auditório CEAGRI II
TITLE:

FROM COTTON GROWING SEASON TO OFF-SEASON IN THE CERRADO: REPRODUCTION AND SUSCEPTIBILITY OF THE COTTON BOLL WEEVIL TO MALATHION

KEY WORDS:

Anthonomus grandis grandis, reproductive biology, malathion, resistance mitigation.

PAGES: 89
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Entomologia Agrícola
SUMMARY:

The cotton boll weevil, Anthonomus grandis grandis Boh. (Coleoptera: Curculionidae), continues to be the major cotton pest species in Brazil, 43 years after its introduction. The designation of the boll weevil as a key pest of cotton has intensified in the cotton fields of the Cerrado, where crop succession promotes population persistence. The maintenance of boll weevil populations during the off-season is associated with its ability to withstand periods of food scarcity and to exploit diverse resources within the cropping systems adopted in the Cerrado. These factors can directly affect reproductive potential and individual survival, particularly under the selection pressure imposed by insecticide recommendations during the growing season. Understanding reproductive dynamics and susceptibility during both the growing and off-seasons is crucial for developing effective management strategies for the boll weevil and for reducing the selection of resistant individuals. The reproductive status of the boll weevil was evaluated during the growing and off-seasons using populations from different locations in Campo Verde, Mato Grosso. The study also assessed reproductive potential during the off-season based on available diets (pollen, flower buds, and cotton terminals) and examined the impact of the off-season on susceptibility to malathion through concentration–response bioassays. Despite reduced reproductive activity during the off-season, a substantial portion of the population retained reproductive capability, reinforcing the importance of off-season food availability for survival, reproduction, and reinfestation of the subsequent crop cycle. Diet influenced reproductive parameters, with pollen and flower buds supporting greater reproductive potential than cotton terminals. Susceptibility to malathion varied over time, with fluctuations attributed to population phenology across the cotton growing and off-seasons. Populations collected at the end of the growing season exhibited reduced susceptibility, whereas those collected after the off-season showed relatively increased sensitivity. Overall, the results indicate that the off-season is a critical period for regulating reproductive capacity and insecticide susceptibility, directly influencing population dynamics and resistance selection in the cotton boll weevil in the Cerrado. These findings highlight the need for management strategies that consider the insect’s reproductive biology throughout the agricultural year, particularly during the off-season, to reduce population infestation and mitigate insecticide resistance.

COMMITTEE MEMBERS:
Presidente - JORGE BRAZ TORRES
Externo ao Programa - 1487701 - WALTER SANTOS EVANGELISTA JUNIOR - UFRPEExterno à Instituição - MARCOS GINO FERNANDES - UFGD
Externo à Instituição - GUILHERME GOMES ROLIM
Externo à Instituição - ROGÉRIO LIRA