Insecticides in Use and Risk of Control Failure of Boll Weevil (Coleoptera: Curculionidae) in the Brazilian Cerrado.

Growers rely on synthetic insecticides to control the boll weevil throughout the reproductive cotton stage. An average of 19.6 insecticide applications (range: 10 to 30) for control of boll weevil were found in a survey with growers in the Brazilian Cerrado, covering an area of 494,100 hectares of cotton.

Field-evolved resistance to beta-cyfluthrin in the boll weevil: Detection and characterization.

Background: Insecticide resistance in arthropods is an inherited trait that has become a major cause of insect pest control failure. Monitoring the level of susceptibility and characterization of the type of resistance of key pest species aims to determine the risk of resistance selection in time to take action to mitigate control failures. Seven populations of the boll weevil, Anthonomus grandis grandis, collected from cotton fields in the Semiarid and Cerrado areas of Brazil, were screened for their resistance to malathion and beta-cyfluthrin, insecticides widely recommended for control of boll weevil and other pests.

Dispersal of boll weevil toward and within the cotton plant and implications for insecticide exposure.

Background: Immature stages of boll weevil complete development endophytically leaving only the adult stage accessible for chemical control. We tested the hypothesis that boll weevil colonization of the cotton plants significantly affects their exposure to sprayed insecticides. We determined the adult dispersal toward and within cotton plants, lethal time (LT), and residual control by recommended insecticides (malathion, carbosulfan, thiamethoxam, fipronil, beta-cyfluthrin, lambda-cyhalothrin, and thiamethoxam + lambda-cyhalothrin) through dried residue exposure and residual control regarding the leaf position in the upper and the lower thirds of the treated plant canopy.

Sublethal Effects of Insect Growth Regulators on Boll Weevil (Coleoptera: Curculionidae).

Immature stages of the boll weevil, Anthonomus grandis grandis Boh. (Coleoptera: Curculionidae), develop protected inside cotton fruiting structures. Therefore, the adult beetles have become the main target of insecticide applications.

Susceptibility of Cotton Boll Weevil (Coleoptera: Curculionidae) to Spinosyns.

The control of boll weevil, Anthonomus grandis grandis Boh., relies primarily on synthetic insecticides. Although insecticides are registered to spray cotton fields against boll weevils, only a few offer satisfactory control and most have broad-spectrum action.