Effects of Bt Corn on the Development and Fecundity of Corn Earworm (Lepidoptera: Noctuidae).
J Econ Entomol
; 111(5): 2233-2241, 2018 09 26.
Article
in En
| MEDLINE
| ID: mdl-29986034
ABSTRACT
The corn earworm, Helicoverpa zea (Boddie) (Lepidoptera Noctuidae), is only moderately susceptible to most toxins from the bacterium Bacillus thuringiensis (Bt) expressed in transgenic corn. To better understand the impact of Bt corn on the life cycle of H. zea, we collected pupae of H. zea during 2014-2016 in North Carolina, South Carolina, and Mississippi from corn hybrids expressing Cry1Ab, Cry1F, Cry1F + Cry1Ab, Cry1F + Cry1Ab + Vip3Aa20, Cry1A.105 + Cry2Ab2, and Cry1A.105 + Cry2Ab2 + Cry1F, as well as from non-Bt near-isolines. We investigated the effect of Bt corn on pupal weight, fecundity, and egg viability of H. zea. Pupal weights were significantly reduced for males and females from all Bt hybrids compared with non-Bt near-isolines. Female pupae from the hybrid expressing Cry1F + Cry1Ab were also significantly lighter relative to those from the near-isolines expressing only Cry1F. Reductions in pupal weight did not result in any detectable effects on fecundity or egg viability. The reduction in pupal weight in the hybrids expressing Cry1F and Cry1F + Cry1Ab significantly declined over time in South Carolina, possibly indicating developing resistance to these Bt toxins. These data can be incorporated into insect resistance management models used to improve risk management decisions regarding H. zea in Bt crops in the complex landscapes of the southern United States.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Bacterial Proteins
/
Endotoxins
/
Hemolysin Proteins
/
Moths
Type of study:
Prognostic_studies
Limits:
Animals
Country/Region as subject:
America do norte
Language:
En
Journal:
J Econ Entomol
Year:
2018
Document type:
Article
Affiliation country:
Seychelles