How to translate text using browser tools
8 January 2020 Evaluation of Insecticide Thresholds in Late-Planted Bt and Non-Bt Corn for Management of Fall Armyworm (Lepidoptera: Noctuidae)
Tom R. Bilbo, Francis P. F. Reay-Jones, Jeremy K. Greene
Author Affiliations +
Abstract

The fall armyworm, Spodoptera frugiperda (J. E. Smith), is a major pest of corn in North and South America. It is managed primarily with transgenic corn-producing insecticidal proteins of Bacillus thuringiensis (Bt), but the development of resistance threatens their durability and necessitates the use of alternative management strategies. We conducted late-planted field trials during 2016 and 2017 in South Carolina using natural infestations. We evaluated the use of Bt and non-Bt corn hybrids in combination with foliar applications of chlorantraniliprole at varying infestation thresholds to protect field corn from infestation and damage and determine effects on grain yield. All Bt hybrids were more effective at reducing fall armyworm infestation rates and leaf injury than multiple insecticide sprays, and no Bt hybrid reached the lowest infestation threshold (20%) to require supplemental insecticide treatments, despite infestations in non-Bt corn reaching >68% in each year. The only Bt and/or insecticide treatment to significantly reduce ear feeding or the proportion of ears injured (mainly by Helicoverpa zea [Boddie]) was the Bt hybrid pyramid producing Vip3A. However, significant protection of yield was detected only in the Bt hybrids producing Cry1A.105 + Cry2Ab2. All Bt traits tested in this study were effective in reducing infestation and feeding damage from fall armyworm, although this did not always result in significant protection of yield. Our results demonstrate the potential and limitations of using chlorantraniliprole with Bt (when resistance is present) and non-Bt corn to manage this pest.

© The Author(s) 2020. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Tom R. Bilbo, Francis P. F. Reay-Jones, and Jeremy K. Greene "Evaluation of Insecticide Thresholds in Late-Planted Bt and Non-Bt Corn for Management of Fall Armyworm (Lepidoptera: Noctuidae)," Journal of Economic Entomology 113(2), 814-823, (8 January 2020). https://doi.org/10.1093/jee/toz364
Received: 7 October 2019; Accepted: 19 December 2019; Published: 8 January 2020
JOURNAL ARTICLE
10 PAGES

This article is only available to subscribers.
It is not available for individual sale.
+ SAVE TO MY LIBRARY

KEYWORDS
Bacillus thuringiensis corn
chlorantraniliprole
Spodoptera frugiperda
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top