Corn Earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae)

2006 ◽  
pp. 617-620
Keyword(s):  
Helicoverpa Zea ◽  
Corn Earworm ◽  
Lepidoptera Noctuidae

Field Evaluation of Transgenic Corn Containing a Bacillus thuringiensis Berliner Insecticidal Protein Gene Against Helicoverpa zea (Lepidoptera: Noctuidae)

1996 ◽  
Vol 31 (3) ◽  
pp. 340-346 ◽  
Author(s):  
Steven R. Sims ◽  
Jay C. Pershing ◽  
Barbara J. Reich
Keyword(s):  
Bacillus Thuringiensis ◽  
Helicoverpa Zea ◽  
Negative Relationship ◽  
Field Evaluation ◽  
Corn Earworm ◽  
Insecticidal Protein ◽  
Transgenic Corn ◽  
First Instar ◽  
Transgenic Lines ◽  
Lepidoptera Noctuidae

Twelve independently transformed lines of transgenic corn (Zea mays L.) expressing the CryIA(b) insecticidal protein from Bacillus thuringiensis var. kurstaki were field tested to evaluate their resistance to the corn earworm, Helicoverpa zea (Boddie). Silks of the primary (=top) ears of transgenic [CryIA(b) positive] and isoline control plants [no CryIA(b) protein] were artificially infested with first-instar H. zea larvae and the length of ear penetration was measured after 19 d. Eight of the 12 lines had significantly less ear damage than their respective isoline controls; 3 transgenic lines reduced H. zea feeding damage by > 75% and stunted surviving H. zea larvae. Concentration of the CryIA(b) protein (μg/g fresh weight) in silks of the transgenic lines, determined using ELISA, ranged from 0.0 to 1.28 μg/g. Within transgenic lines, there was a weak (P < 0.06) negative relationship between the concentration of CryIA(b) protein in fresh silks and the length of H. zea ear penetration.

Influence of Panicle Maturity on Infestation of Grain Sorghum by Corn Earworm and Sorghum Webworm (Lepidoptera: Noctuidae) in Georgia

1991 ◽  
Vol 26 (4) ◽  
pp. 419-424
Author(s):  
J. R. Chamberlin ◽  
J. N. All
Keyword(s):  
Helicoverpa Zea ◽  
Paired Comparison ◽  
Larval Density ◽  
Field Tests ◽  
Grain Sorghum ◽  
Corn Earworm ◽  
Egg Parasitism ◽  
Low Levels ◽  
Sorghum Webworm ◽  
Lepidoptera Noctuidae

The influence of panicle maturity on oviposition by the corn earworm, Helicoverpa zea (Boddie), and sorghum webworm, Celama sorghiella (Riley), was investigated on grain sorghum in Georgia during 1986 and 1987. Stage of panicle development, density of corn earworm and sorghum webworm, and egg parasitism by Trichogramma spp. were recorded at 2–3 day intervals in three field tests. Sorghum webworm and corn earworm began oviposition as panicles emerged from the boot. Oviposition peaked 4–8 days later, near the time panicles began anthesis, but then declined quite rapidly. Oviposition by sorghum webworm ceased approximately 10–12 days after panicle emergence began. Corn earworm oviposition continued at low levels until sampling was terminated 14 - 17 days after panicles began emgergence. Rainfall appeared to mediate effects of panicle maturity on oviposition. Corresponding peaks in larval density were not observed for corn earworm or sorghum webworm, possibly because of heavy parasitism by Trichogramma spp. A paired comparison procedure was used to determine preference of small, medium, and large corn earworm larvae for panicles of different maturity. Early instars preferred newly flowered panicles and concentrated feeding on pollen filled anthers. Late instars preferred panicles in the soft-hard dough stages, while intermediate instars exhibited no significant preference. These data suggest that corn earworm oviposition is concentrated at anthesis because pollen enhances larval development and survival.

scholarly journals Corn Earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae)

EDIS ◽  
1969 ◽  
Vol 2002 (7) ◽  
Author(s):  
John L. Capinera
Keyword(s):  
Helicoverpa Zea ◽  
Cooperative Extension ◽  
Cooperative Extension Service ◽  
Corn Earworm ◽  
Extension Service ◽  
University Of Florida ◽  
Agricultural Sciences ◽  
Lepidoptera Noctuidae

This document is EENY-145, one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: July 2000. https://edis.ifas.ufl.edu/in302

Effects of Inherited Sterility and Insect Resistant Dent-Corn Silks on Helicoverpa zea (Lepidoptera: Noctuidae) Development

1992 ◽  
Vol 27 (4) ◽  
pp. 413-420 ◽  
Author(s):  
J. E. Carpenter ◽  
B. R. Wiseman
Keyword(s):  
Helicoverpa Zea ◽  
Control Strategies ◽  
Developmental Time ◽  
Corn Earworm ◽  
Normal Female ◽  
Dent Corn ◽  
The Mean ◽  
Lepidoptera Noctuidae ◽  
Inherited Sterility ◽  
Meridic Diet

Male and female corn earworm, Helicoverpa zea (Boddie), adults were exposed to a substerilizing dose (10 krads) of gamma radiation after which their progeny were reared on a meridic diet containing selected concentrations of dry silk collected from resistant dent corn genotypes. Significant interactions were observed between the developmental time of progeny from irradiated females and progeny from normal parents and meridic diets with increasing degrees of resistance. A significant interaction also was observed between the mean larval weights of normal and substerile larvae and diets with increasing degrees of resistance. The 9-d weight of normal larvae was significantly higher than the weight of substerile larvae at the lowest degree of resistance, but differences between the weight of normal and substerile larvae at the highest degree of resistance were not significant. Larvae from irradiated male by normal female crosses were equally competitive with normal larvae for all measured parameters. Data from this study suggest that plant resistance and inherited sterility would be compatible control strategies for the management of H. zea populations.

Compatibility of Nuclear Polyhedrosis Viruses and Inherited Sterility for Control of Corn Earworm and Fall Armyworm (Lepidoptera: Noctuidae)

1997 ◽  
Vol 32 (2) ◽  
pp. 148-153 ◽  
Author(s):  
J. J. Hamm ◽  
J. E. Carpenter
Keyword(s):  
Helicoverpa Zea ◽  
Nuclear Polyhedrosis Virus ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Management Approach ◽  
Significant Difference ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
Lepidoptera Noctuidae ◽  
Inherited Sterility

Inherited sterility has been proposed as a means of suppressing the populations of the corn earworm, Helicoverpa zea (Boddie), and the fall armyworm, Spodoptera frugiperda (J. E. Smith). If nuclear polyhedrosis viruses could be used to kill larvae, thereby reducing the number of moths in the field populations, fewer moths treated with substerilizing doses of irradiation would need to be released. However, for these two methods to be compatible, the progeny of substerile moths should be no more susceptible to the virus than the progeny of the field populations. The corn earworm nuclear polyhedrosis virus (Elcar™) was bioassayed against corn earworm larvae from untreated moths and larvae from male, female, and male and female moths treated with 100 Gy of irradiation and larvae from male moths treated with 150 Gy of irradiation. The fall armyworm nuclear polyhedrosis virus was bioassayed against fall armyworm larvae from untreated moths and larvae from male moths treated with 100 to 150 Gy of irradiation. There was no significant difference between susceptibility of larvae from untreated moths and larvae from irradiated moths. Thus, the use of nuclear polyhedrosis viruses for control of larvae should be compatible with the release of substerilized moths as part of an integrated pest management approach for area-wide management of the corn earworm and fall armyworm.

Mortality of the Corn Earworm (Lepidoptera: Noctuidae) on Sorghum Panicles in Georgia

2006 ◽  
Vol 41 (4) ◽  
pp. 292-304 ◽  
Author(s):  
P. Glynn Tillman
Keyword(s):  
Helicoverpa Zea ◽  
Larval Mortality ◽  
Egg Parasitoid ◽  
Corn Earworm ◽  
Cotesia Marginiventris ◽  
Mortality Factors ◽  
Geocoris Punctipes ◽  
Lady Beetles ◽  
Nuclear Polyhedrosis ◽  
Lepidoptera Noctuidae

The mortality of the corn earworm, Helicoverpa zea (Boddie), on sorghum panicles in Georgia was determined in a 2-yr study. Percent total real mortality (rx) of H. zea exceeded 99% for each year and planting date. Percent total real mortality was highest for eggs followed by 1st instars. Parasitization and predation were the primary mortality factors for eggs on sorghum panicles. Larval mortality was due in part to predation, parasitization, and infection by pathogens. Trichogramma pretiosum Riley was the only egg parasitoid observed on sorghum panicles. Orius insidiosus (Say) was the predominant predator of H. zea. Other predators observed feeding on H. zea included the big-eyed bug, Geocoris punctipes (Say), the spined soldier bug, Podisus maculiventris (Say), green lynx spiders, Peucetia viridans (Hentz), and lady beetles (mainly Hippodamia convergens Guérin-Méneville). A variety of parasitoids attacked larvae on sorghum. The braconid Cotesia marginiventris (Cresson) parasitized small to medium-sized larvae. The tachinids Eucelatoria rubentis Coquillett and Archytas marmoratus (Townsend) parasitized large larvae. Two pathogens, HzNPV, a naturally-occurring nuclear polyhedrosis virus of H. zea, and the fungus, Entomophthora aulicae (Reichardt) G. Winter, caused mortality of larvae. In conclusion, biological control by natural enemies of H. zea on sorghum panicles resulted in significant mortality for this pest.

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