Longevity and Egg Development of Adult Female Boll Weevils Fed Exclusively on Different Parts and Stages of Cotton Fruiting Bodies.

Authors: Showler, Allan

Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/29/2008
Publication Date: 3/21/2008
Citation: Showler, A.T. 2008. Longevity and egg development of adult female boll weevils fed exclusively on different parts and stages of cotton fruiting bodies. Entomologia Experimentalis et Applicata. 127(2):125-132.

Interpretive Summary: Although it is known that cotton fruiting bodies (squares and bolls), particularly squares, induce boll weevil egg production while other parts of the cotton plant do not, the contributions of the inner reproduction portions of the fruiting bodies and the outer ‘rinds’ have not been determined. This study involved feeding rinds or inner reproductive portions of various sizes and ages of the fruiting bodies to adult female boll weevils to determine the extent to which each enabled gravidity and fecundity, and boll weevil longevity. Square reproductive portions and rinds (particularly rinds from large squares) enabled gravidity, but the rinds generally contributed less to fecundity than reproductive portions, and both portions supported boll weevils longer than a starvation diet, excluding the rind and reproductive portions of old, hardened bolls.

Technical Abstract: The capacities of the external rind or internal reproductive portions of cotton, Gossypium hirsutum L., squares of various sizes (match-head, 2–3-mm-diameter; medium, 3.1–5.4-mm-diameter; and large, 5.5–8-mm-diameter) and bolls of various ages (post-bloom, 1–2-d after flower petal abscission; young, 5–10 d; and old, 3–5 wk) to influence adult boll weevil, Anthonomus grandis grandis Boheman, longevity and egg production were evaluated in laboratory assays. Although the reproductive portions of squares were expected to contribute the most toward enhancing boll weevil longevity (e.g., medium square reproductive portions: ~170 d weevil longevity), rinds also supported longevity to a substantial extent (~100 d), and to lesser degrees, the reproductive portions and rinds of post-bloom bolls and young bolls each supported adult boll weevils for longer than did a starvation diet. As anticipated, square reproductive portions contributed toward the weevil’s gravidity and fecundity, but this study also reports that a steady diet of rinds particularly from large squares enabled substantial gravidity and limited fecundity. Diets of rinds or reproductive portions of post-bloom bolls resulted in ~50% of female boll weevils becoming gravid with one or more chorionated eggs. Maintaining boll weevils on reproductive portions and rinds of old bolls did not enhance longevity or egg development. These findings further our understanding of boll weevil field ecology and offer clues about the relationships between boll weevil nutrition and reproduction.