Management of Corn Earworm and Fall Armyworm (Lepidoptera: Noctuidae) Injury on a Sweet Corn Hybrid Expressing a cryIA(b) Gene

1999 ◽  
Vol 92 (5) ◽  
pp. 1217-1222 ◽  
Author(s):  
R. E. Lynch ◽  
B. R. Wiseman ◽  
H. R. Sumner ◽  
D. Plaisted ◽  
D. Warnick
Keyword(s):  
Sweet Corn ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Lepidoptera Noctuidae ◽  
Corn Hybrid

Evaluation of Bt Transgenic Sweet Corn Hybrids for Resistance to Corn Earworm and Fall Armyworm (Lepidoptera: Noctuidae) using a Meridic Diet Bioassay2

1999 ◽  
Vol 34 (4) ◽  
pp. 415-425 ◽  
Author(s):  
B. R. Wiseman ◽  
R. E. Lynch ◽  
D. Plaisted ◽  
D. Warnick
Keyword(s):  
Spodoptera Frugiperda ◽  
Helicoverpa Zea ◽  
Sweet Corn ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Laboratory Bioassay ◽  
Corn Hybrids ◽  
Pinto Bean ◽  
Highly Correlated ◽  
Lepidoptera Noctuidae

A laboratory bioassay was used to evaluate Bt transgenic sweet corn hybrids for resistance against the corn earworm, Helicoverpa zea (Boddie), and the fall armyworm, Spodoptera frugiperda (J. E. Smith). Whorl leaves, silks, and kernels, either fresh or oven-dried and ground with a mill, were incorporated into a dilute pinto bean diet and bioassayed against neonate, 3-, or 6-day-old larvae. Regardless of age of the larvae, results with the diet bioassay using fresh silks, oven-dried silks or fresh kernels were highly correlated with those for the fresh silk bioassay. Differences in susceptibility between insect species to the CrylA(b) toxin produced in the transgenic plants were also readily discernable using the diet bioassay. Based on results of the bioassays, Novartis sweet corn hybrids containing a crylA(b) gene gene for δ-endotoxin production were very highly resistant to leaf, silk and kernel feeding by the corn earworm and highly resistant to leaf and silk feeding by the fall armyworm.

Ear Pests and Damage to Organic, Conventional and Bt-Protected Sweet Corn Grown in Central Kentucky

2009 ◽  
Vol 44 (4) ◽  
pp. 383-390
Author(s):  
John D. Sedlacek ◽  
Karen L. Friley ◽  
Steve L. Hillman
Keyword(s):  
Helicoverpa Zea ◽  
European Corn Borer ◽  
Sweet Corn ◽  
Crop Protection ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Genetically Engineered ◽  
Corn Borer ◽  
Sap Beetles ◽  
Southwestern Corn Borer

Sweet corn (Zea mays L. var. rugosa) was grown in replicated plots in 2004 and 2006 using organic, conventional, and genetically-engineered (Bt) production practices. Organic plots were treated with Entrust® (Dow AgroSciences LLC, Indianapolis, IN) whereas conventional and Bt sweet corn plots were treated with Warrior® (Syngenta Crop Protection, Inc., Greensboro, NC). All plots were treated once at silk emergence. Organic and conventional plots were treated again 1 wk later. Twenty-five ears were harvested from row centers in each treatment subplot to quantify ear pests and assess ear damage. The highest number of corn earworm, Helicoverpa zea (Boddie), larvae were found on organically-grown sweet corn. European corn borer, Ostrinia nubilalis (Hübner); southwestern corn borer, Diatraea grandiosella Dyar; and fall armyworm, Spodoptera frugiperda (J.E. Smith), larvae were not found as frequently. Neither corn earworm nor European corn borer larvae were found on Bt sweet corn ears. Sap beetles, Carpophilus lugubris Murray, were found on all 3 types of sweet corn. Organically and conventionally-grown sweet corn had a greater number of tip-damaged ears and numbers of damaged kernels per ear than Bt sweet corn. Ear length and weight were the same for all 3 types of sweet corn. Based on the information generated in this study, growing late-planted sweet corn organically or conventionally on a large commercial scale with a limited spray program and without using other types of ear pest management does not appear to be a practical or profitable option in central Kentucky.

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