ARS | Publication request: TIME OF COTTON SQUARE ABSCISSION AND ADULT BOLL WEEVIL EMERGENCE FROM FALLEN SQUARES UNDER LOWER RIO GRANDE VALLEY FIELD CONDITIONS

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: January 5, 2004
Publication Date: N/A

Interpretive Summary: Boll weevils spend part of their life inside infested cotton fruit where they are protected from applied insecticides. Information about the duration of the boll weevil life cycle from egg lay in cotton fruit, through fruit shedding, to adult emergence from shed fruit is available for temperate regions, but not for the subtropical Lower Rio Grande Valley of Texas. In this study, the interval between egg lay and fruit shedding was 3.3 days shorter than in temperate areas, and the interval to adult emergence was 1.2 days longer. These findings indicate that the intervals during which boll weevils are protected from applied insecticides during the cotton growing season are different for subtropical and temperate regions, and knowledge of these intervals will lead to more effective timing and pest thresholds for insecticide applications.

Technical Abstract: This study found that 6.2 ± 0.4 d elapsed between boll weevil, Anthonomus grandis grandis Boheman, oviposition and square abscission under field conditions in the Lower Rio Grande Valley of Texas. Oviposition to adult weevil emergence from the square took 18.5 ± 0.9 d. Although significant minimum and maximum temperature differences were detected between May and June, oviposition to square abscission and adult emergence periods were not significantly affected.