Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/15/2012
Publication Date: 2/1/2013
Citation: Neves, R.C., Showler, A.T., Pinto, E.S., Bastos, C.S., Torres, J.B. 2013. Reducing boll weevil populations by clipping terminal buds and removing abscised fruiting bodies. Entomologia Experimentalis et Applicata. 146(2):276-285. Interpretive Summary: In areas of Brazil where low-input agriculture must be practiced in cotton because of regional economic conditions, cultural methods of boll weevil control are needed. In this study, collection of fallen, infested cotton squares, and clipping plant terminals when many bolls have matured, were assessed for their individual and collective impacts on boll weevil populations in the cotton plants. Collection of fallen squares, clipping plant terminals, and the combination of both tactics reduced boll weevil infestation by 64%, 60%, and 79%, respectively.
Technical Abstract: The boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae) punctures cotton squares and young bolls during feeding and oviposition, causing abscission of flower buds (squares) in the instance of oviposition. Fallen squares are a source of next generation adult boll weevils that either infest the surrounding cotton, or, if late season, overwinter, particularly in the warm subtropics, to the following spring planting. We examined the impact of collecting abscised cotton fruiting bodies (squares and bolls) and clipping plant terminals at 50% boll maturation under field and field cage conditions, and the rate of parasitism on immature stages of the pest. We found that collecting abscised reproductive structures, clipping plant terminals, and using both practices together reduced the boll weevil population by 64%, 60%, and 79%, respectively. Because they are practicable measures for areas where cotton is predominantly grown by smallholders, such as semiarid states in northeastern Brazil, these tactics could be incorporated into a relatively low input integrated pest management strategy for this key cotton pest.