Midsouth Entomologist
Abstract
Laboratory, greenhouse, and field experiments were conducted to evaluate the efficacy of cotton (Gossypium hirsutum L.) expressing two proteins of Bacillus thuringiensis Berliner (‘Bollgard II’ expressing Cry1Ac + Cry2Ab, Monsanto Company, St. Louis, MO) against economically important lepidopteran pests in Mississippi. Results from leaf assays conducted in the laboratory indicate that Bollgard II cotton caused significantly higher mortality and growth inhibition of Helicoverpa zea (Boddie), Heliothis virescens (F.), Spodoptera frugiperda (J.E. Smith), S. exigua (Hubner), Pseudoplusia includes (Walker), and Estigmene acrea (Drury) than Cry1Ac onlyand non-Bt cotton. In greenhouse studies, Bollgard II cotton provided significantly enhanced protection against common defoliating pests (i.e., S. exigua and P. includens) compared with Bollgard and non-Bt cotton. In these studies, non-Bt and Bollgard cotton genotypes sustained nearly identical levels of defoliation by these pests. Overall, these results suggest that the combination of two insecticidal proteins in Bollgard II cotton significantly improved efficacy against lepidopteran pests compared to Bollgard cotton. Under field conditions with high populations of H. zea or other occasional lepidopteran pests (e.g., S. frugiperda), Bollgard II cotton should provide a much higher level of overall protection compared with that for Bollgard cotton plants.
Recommended Citation
Akin, D. S.; Stewart, S. D.; Layton, M. B.; and Mills, J. A.
(2011)
"Efficacy of Cotton Expressing Pyramided Bacillus thuringiensis Insecticidal Proteins Against Lepidopteran Pest,"
Midsouth Entomologist: Vol. 4:
No.
1, Article 1.
Available at:
https://scholarsjunction.msstate.edu/midsouthent/vol4/iss1/1