Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/5/2005
Publication Date: 6/28/2005
Citation: Showler, A. 2005. Cotton fruit size or age on boll weevil fecundity and oviposition. In: Proceedings of the Beltwide Cotton Conferences, January 4-7, 2005, New Orleans, Louisiana. 2005 CDROM.
Interpretive Summary: Preventive insecticide treatments against boll weevils at the early fruiting stage of cotton, when fruits (squares and bolls) are small, in south Texas has not shown conclusive advantages for protecting the crop in previous studies. This research shows that more boll weevils develop eggs, and more eggs are developed in each female, when fed on large squares than on small squares, or on bolls of any age. Because boll weevils also prefer to feed on and lay eggs in large squares in the field, protection of the large squares instead of small squares might be a more effective pest management strategy.
Technical Abstract: Boll weevil, Anthonomus grandis grandis Boheman (Coloeoptera: Curculionidae), populations in the Lower Rio Grande Valley of Texas increase strongly during cotton squaring. Boll weevils fed on large (5.5-8-mm-diameter) squares for 7 d resulted in >/=3.8-fold more gravid females that developed 4.8-fold more chorionated eggs per female than weevils fed on match-head-sized (2-3-mm-diameter) squares, or post-bloom, young (5-10-d-old), or old (3-5-wk-old) bolls. In the field, large squares had 7.8- and 25-fold more feeding punctures than match-head-sized squares and bolls, respectively. Greater feeding on large squares, and the associated greater fecundity explain rapid weevil population build-ups observed shortly after large squares become well established.