scholarly journals Response of Bt and Non-Bt Cottons to High Infestations of Bollworm (Helicoverpa zea Boddie) and Tobacco Budworm (Heliothis virescens (F.)) under Sprayed and Unsprayed Conditions

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 759 ◽  
Author(s):  
Allen ◽  
Luttrell ◽  
Little ◽  
Parys ◽  
Perera
Keyword(s):  
Heliothis Virescens ◽  
Helicoverpa Zea ◽  
Tobacco Budworm ◽  
Insect Damage ◽  
Bt Cotton ◽  
Insecticide Treatment ◽  
Early Maturing ◽  
Insect Infestations ◽  
Experimental Plots ◽  
Maturity Groups

Early-maturing and full-season Bt and non-Bt cottons were exposed to high densities of tobacco budworm (Heliothis virescens (F.)) and bollworm (Helicoverpa zea Boddie) in 0.04 ha field cages during the summers of 2011 and 2012 to measure the possible need for supplemental use of insecticides on Bt cotton. Fruit survival within-season and at-harvest was carefully mapped on individual plants within comparative plots of all cottons untreated and sprayed with lambda-cyhalothin (0.0448 kg a.i./ha) or chlorantraniliprole (0.1009 kg a.i./ha) following insect infestations. Differences in lint yields among cotton maturity groups were not always detected, but early-maturing Bt cottons were among the higher yielding experimental plots for both years. Depending on the insecticide treatment, average harvested fruit ranged from 0.3 to 7.1 open bolls per plant for non-Bt cotton plots, while Bt cotton plots ranged from 1.8 to 7.5 open bolls per plant during the two-year study. Bt cottons generally protected fruit from insect damage and resulted in final yields comparable to those of insecticide sprayed Bt and non-Bt cottons. Unsprayed non-Bt cottons were significantly damaged by insects in these high-infestation environments.

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.

scholarly journals The nucleopolyhedroviruses of Rachiplusia ou and Anagrapha falcifera are isolates of the same virus

1999 ◽  
Vol 80 (10) ◽  
pp. 2793-2798 ◽  
Author(s):  
Robert L. Harrison ◽  
Bryony C. Bonning
Keyword(s):  
Heliothis Virescens ◽  
Helicoverpa Zea ◽  
European Corn Borer ◽  
Biological Activities ◽  
Corn Earworm ◽  
Tobacco Budworm ◽  
Predicted Amino Acid Sequence ◽  
Corn Borer ◽  
Anagrapha Falcifera ◽  
Relationship Of

The 7·8 kb EcoRI-G fragment of Rachiplusia ou multicapsid nucleopolyhedrovirus (RoMNPV), containing the polyhedrin gene, was cloned and sequenced. The sequence of the fragment was 92·3% identical to the sequence of the corresponding region in the Autographa californica (Ac)MNPV genome. A comparison of the EcoRI-G sequence with other MNPV sequences revealed that RoMNPV was most closely related to AcMNPV. However, the predicted amino acid sequence of RoMNPV polyhedrin shared more sequence identity with the polyhedrin of Orygia pseudotsugata MNPV. In addition, the RoMNPV sequence was almost completely identical (99·9%) to a previously published 6·3 kb sequence of Anagrapha falcifera MNPV (AfMNPV). The Eco RI and HindIII restriction fragment profiles of RoMNPV and AfMNPV also were nearly identical, with an additional EcoRI band detected in RoMNPV DNA. Bioassays of these viruses with three different hosts (the European corn borer, Ostrinia nubilalis H übner, the corn earworm, Helicoverpa zea Boddie, and the tobacco budworm, Heliothis virescens Fabricius) failed to detect any differences in the biological activities of RoMNPV and AfMNPV. These results indicate that RoMNPV and AfMNPV are different isolates of the same virus. The taxonomic relationship of Ro/AfMNPV and AcMNPV is discussed.

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.

Bionomics of the Fall Armyworm (Lepidoptera: Noctuidae) and Its Ectoparasitic Nematode, Noctuidonema guyanense, in South Georgia

1996 ◽  
Vol 31 (2) ◽  
pp. 209-217
Author(s):  
C. E. Rogers ◽  
O. G. Marti ◽  
L. D. Chandler ◽  
A. M. Simmons
Keyword(s):  
Spodoptera Frugiperda ◽  
Heliothis Virescens ◽  
Helicoverpa Zea ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Cotton Bollworm ◽  
Tobacco Budworm ◽  
Beet Armyworm ◽  
South Georgia ◽  
Lepidoptera Noctuidae

The fall armyworm, Spodoptera frugiperda (J. E. Smith), is a perennial immigrant pest of several crops in south Georgia. Moths of S. frugiperda commonly are infested by an ectoparasitic nematode, Noctuidonema guyanense Remillet and Silvain in the Southeast. The seasonal chronology and natural association of these species are reported for Tift Co. from 1988 to 1994. Seasonal influxes of non-infested moths usually arrive in late April and dissipate in early November. Seasonal influxes of infested male moths follow the initial immigrants by 4 to 6 wks and disappear in the fall from 1 to 2 mos earlier than the general moth populations. Feral male moths that are moderately worn and infested by N. guyanense weigh less than moderately worn, non-infested males. Noctuidonema guyanense infests moths of several species of noctuids, but it has not been found on the cotton bollworm/corn earworm [Helicoverpa zea (Boddie)], tobacco budworm [Heliothis virescens (Fab.)], or beet armyworm [S. exigua (Hubner)].

Proboscidea louisianica: An Unreported Host of Heliothis virescens (Lepidoptera: Noctuidae)

1995 ◽  
Vol 30 (4) ◽  
pp. 429-433
Author(s):  
M. L. Laster
Keyword(s):  
Heliothis Virescens ◽  
Helicoverpa Zea ◽  
Survival Rates ◽  
Host Record ◽  
Tobacco Budworm ◽  
Semisynthetic Diet ◽  
New Host ◽  
New Host Record ◽  
Cardiochiles Nigriceps ◽  
Devil’S Claw

The tobacco budworm, Heliothis virescens (F.), was found to be strongly attracted to devil's claw, Proboscidea louisianica (Mill.) Thellung, plants. Of 160 larvae collected from the plants in 1992, 99.4% were H. virescens, 0.6% were Helicoverpa zea (Boddie), 42.5% died from infection by undetermined disease pathogens, and 11.3% H. virescens were parasitized by Cardiochiles nigriceps Vierick. Of 112 larvae collected from P. louisianica in 1994, 90.2% were H. virescens, 9.8% were H. zea, 59.8% died from infection by undetermined pathogens, and 26.7% H. virescens were parasitized by C. nigriceps. Feeding studies showed that P. louisianica was a nutritionally poor host for H. virescens, backcrosses of H. subflexa X H. virescens, and H. zea; when compared with their development on semisynthetic diet, development was much slower, pupal weights were lower, and survival rates were lower for larvae fed P. louisianica than for those fed semisynthetic diet. None of the backcross or H. zea and only one H. virescens female developed on P. louisianica survived to reproduce. This study reports P. louisianica as a new host record for H. virescens. Data show that H. virescens can survive and reproduce on this plant and that P. louisianica could be a major host of H. virescens in the Mississippi Delta if it were to become widespread.

Survival Rates of Tobacco Budworm (Lepidoptera: Noctuidae) Larvae Exposed to Transgenic Cottons Expressing Insecticidal Protein of Bacillus thuringiensis Berliner

2000 ◽  
Vol 35 (2) ◽  
pp. 105-117 ◽  
Author(s):  
C. D. Parker ◽  
V. J. Mascarenhas ◽  
R. G. Luttrell ◽  
K. Knighten
Keyword(s):  
Bacillus Thuringiensis ◽  
Insecticidal Activity ◽  
Heliothis Virescens ◽  
Survival Rates ◽  
Larval Survival ◽  
Tobacco Budworm ◽  
Bt Cotton ◽  
Plant Structure ◽  
Lepidoptera Noctuidae ◽  
Insecticidal Plants

The insecticidal activity of transgenic cottons expressing endotoxin protein of Bacillus thuringiensis Berliner (Bt cotton) was quantified by measuring survival of tobacco budworm, Heliothis virescens (F.), larvae caged on different plant structures for varying lengths of exposure. Percentages of larvae surviving were measured on Bt cottons expressing Cry1Ab and CrylAc protein. Plant structure (terminal, leaf, square or boll) did not affect larval survival, and survival did not differ significantly between CrylAb and CrylAc cottons. Larvae exposed to Bt cotton for only 24 h had higher initial survival than larvae exposed for 48, 72 and 96 h. Larvae first exposed to Bt cotton at 4 d of age had higher survival than those first exposed as neonate or 2-d-old larvae. Survivorship of neonate and 4-d-old larvae exposed to CrylAc cotton was significantly reduced with only 48 h of exposure to the insecticidal plants. Seven-day-old larvae exhibited no significant reduction in survivorship with exposure to CrylAc cotton for 48 h.

Distribution and Abundance of Early-Season Wild Host Plants and Bollworm and Tobacco Budworm Populations (Lepidoptera: Noctuidae) in an Intensively Cropped Area of the Mid-Delta of Mississippi

1991 ◽  
Vol 26 (1) ◽  
pp. 9-16 ◽  
Author(s):  
G. L. Snodgrass ◽  
E. A. Stadelbacher ◽  
J. W. Smith
Keyword(s):  
Heliothis Virescens ◽  
Helicoverpa Zea ◽  
Host Plants ◽  
Tobacco Budworm ◽  
Suitable Habitat ◽  
Pest Species ◽  
Washington County ◽  
Early Season ◽  
Wild Host ◽  
Wild Hosts

An intensively cropped area of the Mississippi Delta located in Washington County, Mississippi was sampled to determine distribution and abundance of early-season wild host plants of Heliothis virescens (F.) and Helicoverpa zea (Boddie), and F1 larval populations on them. The area sampled was approximately 6.4 km square with an approximate area of 4,146 ha. Wild host plants were most numerous along roadsides, ditch and field margins, and in small (usually dry) ditches and their margins. The total area of suitable habitat for these wild hosts was estimated as 98.8 ha which represented approximately 2.4% of the total area. Species of Geranium were the most abundant wild hosts found. Helicoverpa zea and Heliothis virescens were estimated to average a combined total of 62 larvae per ha of wild host plants. These data demonstrate that experiments on the control of both pest species on wild hosts on an area-wide basis in the Delta are possible due to the confinement of these pests and their wild host plants to a relatively small area.

Effects of an Entomopathogenic Nematode and a Nuclear Polyhedrosis Virus on Emergence of Heliothis virescens (Lepidoptera: Noctuidae)

1995 ◽  
Vol 30 (2) ◽  
pp. 243-250 ◽  
Author(s):  
M. R. Bell
Keyword(s):  
Heliothis Virescens ◽  
Untreated Control ◽  
Helicoverpa Zea ◽  
Entomopathogenic Nematode ◽  
Adult Emergence ◽  
Similar Rate ◽  
Tobacco Budworm ◽  
Whitening Agent ◽  
Nuclear Polyhedrosis ◽  
Lepidoptera Noctuidae

Cage tests were conducted during the 1993 growing season to determine the effect of incorporating an entomopathogenic nematode (Steinernema riobravis) in soil under cotton on subsequent emergence of tobacco budworm, Heliothis virescens (L.). When soil under seedling cotton was treated with 240K nematodes per m2 on 13 May, the number of moths emerging in cages was reduced by an average of 66%, compared to the untreated control, for at least 21 days following application. When a similar rate was applied on soil under mature cotton on 12 July, the number of moths emerging in treated cages after developing as larvae on the plants was 57% less over a 39 d period compared to the untreated control. In another cage study, application of the nematodes on wild geranium, Geranium dissectum L., an early-season host of tobacco budworms and cotton bollworms, Helicoverpa zea (Boddie), reduced adult emergence by 36% compared to untreated areas, whereas a single application of baculovirus from the celery looper (600 billion polyhedra per ha) reduced the emergence by 56%. In this latter test, adult emergence was further reduced (73% less than control) when a whitening agent was added to the virus application. These studies indicate than an entomopathogenic nematode, and the use of a whitening agent with baculovirus, might be useful in tobacco budworm management programs.

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