Field Performance of Cottons Expressing Transgenic CryIA Insecticidal Proteins for Resistance to Heliothis virescens and Helicoverpa zea (Lepidoptera: Noctuidae)

1996 ◽  
Vol 89 (1) ◽  
pp. 230-238 ◽  
Author(s):  
J. H. Benedict ◽  
E. S. Sachs ◽  
D. W. Altman ◽  
W. R. Deaton ◽  
R. J. Kohel ◽  
...  
Keyword(s):  
Heliothis Virescens ◽  
Helicoverpa Zea ◽  
Field Performance ◽  
Insecticidal Proteins ◽  
Lepidoptera Noctuidae

Age-Specific Mortality of Helicoverpa zea and Heliothis virescens (Lepidoptera: Noctuidae) Larvae on Flower Buds of Transgenic Cotton Expressing Vip3A and VipCot™ Insecticidal Proteins

2008 ◽  
Vol 43 (4) ◽  
pp. 349-361 ◽  
Author(s):  
P. L. Bommireddy ◽  
B. R. Leonard
Keyword(s):  
Heliothis Virescens ◽  
Helicoverpa Zea ◽  
Tobacco Budworm ◽  
Bt Cotton ◽  
Age Classes ◽  
Flower Buds ◽  
Insecticidal Proteins ◽  
Cotton Industry ◽  
Cumulative Mortality ◽  
Specific Mortality

The age-specific mortality of bollworm, Helicoverpa zea (Boddie), and tobacco budworm, Heliothis virescens (F.), larvae was quantified on flower buds (squares) of transgenic Bacillus thuringiensis (Bt) cotton expressing Vip3A and VipCot™ (Vip3A + CrylAb) proteins. Cumulative mortality levels for both species and all larval ages (2 d, 4 d, 6 d, and 8-d-old) were significantly higher on squares of the Vip3A and VipCot cotton lines compared with that for the nonBt Coker 312 cotton. In general, H. zea and H. virescens larvae demonstrated significantly lower survival on VipCot squares compared with larvae that were offered Vip3A squares. The final cumulative mortality levels of H. zea larvae occurred more rapidly than that observed for H. virescens larvae on Vip3A squares. On Vip3A squares, the rates of peak mortality were similar among H. zea age-classes. Heliothis virescens in 4, 6 and 8-d-old age-classes survived longer than 2-d-old larvae on Vip3A squares. However, on VipCot squares, 8-d-old larvae of both species survived longer compared with other age-classes. Regardless of age-class, no larvae of either species were capable of completing pupation on squares from the VipCot cotton line. The combination of two insecticidal proteins expressed in the VipCot cotton line improved heliothine efficacy levels above that of the single protein in the Vip3A line and should exceed the requirements of the cotton industry for registration and regulation of transgenic Bt cottons. This level of VipCot toxicity to both target species supports continued development of the technology to provide another useful transgenic tool with considerable IPM and IRM value.

Antagonism between Formulations of Different Bacillus thuringiensis Subspecies in Heliothis virescens and Helicoverpa zea (Lepidoptera: Noctuidae)

1998 ◽  
Vol 33 (2) ◽  
pp. 129-135 ◽  
Author(s):  
A. O. Ameen ◽  
J. R. Fuxa ◽  
A. R. Richter
Keyword(s):  
Bacillus Thuringiensis ◽  
Heliothis Virescens ◽  
Helicoverpa Zea ◽  
Insect Species ◽  
Median Lethal Concentrations ◽  
Lepidoptera Noctuidae

Interactions between formulations of the aizawai and kurstaki subspecies of Bacillus thuringiensis Berliner were evaluated by bioassay in Heliothis virescens (F.) and Helicoverpa zea (Boddie). In preliminary experiments, a formulation of subspecies aizawai, Xentari AS®, had significantly (P < 0.05) higher median lethal concentrations (LC50s) in both insect species than formulations based on subspecies kurstaki. Helicoverpa zea was significantly (P < 0.05) more susceptible than H. virescens to one formulation of subspecies kurstaki (Dipel ES®), but the two insects did not differ in susceptibility to Xentari AS® or to a second formulation of subspecies kurstaki (Dipel 6AF®). In H. virescens, Xentari AS® was additive with Dipel 6AF® and significantly (P< 0.05) antagonistic with Dipel ES® and with a third formulation of subspecies kurstaki, Dipel 48A®. In H. zea, Xentari AS® was significantly antagonistic with all three formulations of subspecies kurstaki. This suggests that certain toxin combinations from B. thuringiensis subspecies might not be effective for managing H. virescens and H. zea populations.

Impact of δ-Endotoxin-Producing Transgenic Cotton on Insect–Plant Interactions with Heliothis virescens and Helicoverpa zea (Lepidoptera: Noctuidae)

1993 ◽  
Vol 22 (1) ◽  
pp. 1-9 ◽  
Author(s):  
J. H. Benedict ◽  
E. S. Sachs ◽  
D. W. Altman ◽  
D. R. Ring ◽  
T. B. Stone ◽  
...  
Keyword(s):  
Heliothis Virescens ◽  
Helicoverpa Zea ◽  
Transgenic Cotton ◽  
Plant Interactions ◽  
Lepidoptera Noctuidae

Early Season Application of a Baculovirus for Area-Wide Management of Heliothis/Helicoverpa (Lepidoptera: Noctuidae): 1992 Field Trial

1994 ◽  
Vol 29 (2) ◽  
pp. 192-200 ◽  
Author(s):  
M. R. Bell ◽  
D. D. Hardee
Keyword(s):  
Heliothis Virescens ◽  
Helicoverpa Zea ◽  
Tobacco Budworm ◽  
Emergence Period ◽  
Early Season ◽  
Treated Area ◽  
Untreated Area ◽  
Weed Hosts ◽  
Lepidoptera Noctuidae ◽  
Growing Region

A 9.6-km diam area in the intensive cotton-growing region of the Mississippi Delta was treated with an entomopathogenic virus to determine the effect on populations of adult tobacco budworms, Heliothis virescens (F.), and bollworms, Helicoverpa zea (Boddie), emerging from early season weed hosts. Four aircraft were used to treat ≈ 7,106 ha during 24–28 April at a rate of 100 larval equivalents per ha. Emergence data from cages placed over treated and untreated areas indicated that virus treatments reduced tobacco budworm emergence by 80.6% and bollworm emergence by 46.2%. During the emergence period, tobacco budworm traps in the area surrounding the treated area averaged 11.4 moths per trap per night. Average trap capture per trap per night in the center (6.4 km diam) of the treated area was 6.4 moths, a reduction of 43.9% compared with the untreated area. Correspondingly, reduction in trap counts for bollworm in the center was 21% when compared with the untreated area.

Sign in / Sign up

Export Citation Format

Share Document