Potential Impact of Pyrethroid Resistance in Helicoverpa zea to the Midwest Processing Industry: Sweet Corn and Snap Beans

2007 ◽  
Vol 8 (1) ◽  
pp. 61 ◽  
Author(s):  
Brian R. Flood ◽  
Thomas L. Rabaey
Keyword(s):  
Helicoverpa Zea ◽  
Sweet Corn ◽  
Pyrethroid Resistance ◽  
Corn Earworm ◽  
Pyrethroid Insecticides ◽  
Snap Beans ◽  
Early Instar ◽  
Production Areas ◽  
Treatment Window

Midwest food processors are well positioned to avoid major crop losses, and product contamination resulting from pyrethroid resistance in corn earworm (CEW), Helicoverpa zea (Boddie). However, we do recognize risks associated with late-season plantings, particularly for sweet corn and snap beans. CEW usually migrate into the production areas by late July to mid-August. Crops at risk for most Midwest locations primarily include sweet corn planted after 10 June and snap beans planted after 10 July (about 25% of the Midwest acreage). Pyrethroid insecticides continue to be the commercial standard, with alternative chemistries either ineffective or more expensive. The CEW “treatment window” for sweet corn is from row tassel to dark brown silk and, for snap beans, from bloom to 10 days before harvest. In sweet corn, CEW is only vulnerable as an adult, egg, or early instar feeding on the silk. If left untreated, or with insecticide failure, we anticipate a loss of about one square inch of kernels per larva (2 cases/ton of final cut-corn product). The loss of kernels and the creation of black kernels from contamination associated with feeding injury are estimated to have a market cost in excess of $100/acre, or $6 million for Midwest sweet corn and snap beans. We currently have no effective alternative insecticides for CEW for either crop. In the short term, processors will likely use higher rates of pyrethroids, shorter intervals, and/or additional treatments. Long term, we will increasingly rely on a “process-out” approach to husk out, wash out, and vision-sort larval contaminants and damaged kernels. Accepted for publication 23 February 2007. Published 19 July 2007.

Monitoring for Pyrethroid Resistance in Bollworm (Helicoverpa zea) Populations in Texas: Trends from 2003-2005

2007 ◽  
Vol 8 (1) ◽  
pp. 59 ◽  
Author(s):  
Patricia V. Pietrantonio ◽  
Terry A. Junek ◽  
Roy Parker ◽  
Ed Bynum ◽  
Greg Cronholm ◽  
...  
Keyword(s):  
Helicoverpa Zea ◽  
Crop Production ◽  
Production Systems ◽  
Pyrethroid Resistance ◽  
Monitoring Program ◽  
Analysis Data ◽  
Considerable Variability ◽  
Pyrethroid Insecticides ◽  
Susceptible Populations ◽  
Production Areas

The purpose of this study was to assess the susceptibility of the bollworm, Helicoverpa zea (Boddie), to the pyrethroid cypermethrin in the primary crop production areas of Texas. Pyrethroid insecticides are widely used in cotton and in other production systems, such as grain sorghum and corn. The statewide monitoring program that evaluated resistance in male H. zea was conducted from April to September 2005, surveying nine Texas counties with a total of 5,041 moths from all areas used for analysis. Data from all areas were sent to Texas A&M University Toxicology Laboratory for analysis. Considerable variability in response to cypermethrin was detected in H. zea across the state. Based on LC50 data, the most resistant populations were from Nueces, Uvalde, and Williamson counties while the most susceptible populations were from Ellis, Fisher and Mitchell, Hockley, and Swisher counties. Accepted for publication 2 October 2006. Published 19 July 2007.

Evidence for Decreasing Helicoverpa zea Susceptibility to Pyrethroid Insecticides in the Midwestern United States

2007 ◽  
Vol 8 (1) ◽  
pp. 57 ◽  
Author(s):  
W. D. Hutchison ◽  
E. C. Burkness ◽  
B. Jensen ◽  
B. R. Leonard ◽  
J. Temple ◽  
...  
Keyword(s):  
United States ◽  
Helicoverpa Zea ◽  
Sweet Corn ◽  
Survival Rates ◽  
Field Tests ◽  
Corn Earworm ◽  
High Survival ◽  
Vegetable Crops ◽  
Pyrethroid Insecticides ◽  
Midwestern United States

The corn earworm (CEW), Helicoverpa zea (Boddie), is a highly mobile pest of numerous field and vegetable crops in much of North America. In the Midwestern United States, CEW is a voracious pest of several high-value vegetable crops, including sweet corn, tomatoes, and snap beans, and seed corn grown for the field corn industry. Historically, synthetic pyrethroid insecticides have been cost-effective and have provided excellent control of CEW, with control of larvae in sweet corn exceeding 90%. However, since 2000 pyrethroids have only provided 35 to 45% control in field tests conducted in the Midwest, as indicated by small-plot sweet corn efficacy trials. During 2005, the four most commonly used pyrethroids averaged only 19.3 to 37.3% control of CEW (mean of 5 trials in Minnesota, Wisconsin, Illinois, and Indiana). In addition, the survival of moths exposed to the standard pyrethroid, cypermethrin, using the Adult Vial Test (AVT), indicated high survival rates (44 to 66% at 5 μg cypermethrin and up to 45% survival at 10 μg). These levels are similar to, or higher than recent AVT results from Louisiana and Texas. These states reflect two possible “source” regions of late-season CEW that likely migrate north to the Midwestern states each summer. These results, including the stability of resistance each year in the Midwest, are discussed within the context of developing and expanding a North American resistance monitoring and management network. Accepted for publication 3 June 2007. Published 19 July 2007.

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.

scholarly journals Resistance to insecticides in Heliothine Lepidoptera: a global view

1998 ◽  
Vol 353 (1376) ◽  
pp. 1735-1750 ◽  
Author(s):  
A. R. McCaffery
Keyword(s):  
Helicoverpa Zea ◽  
Resistance Management ◽  
Corn Earworm ◽  
Tobacco Budworm ◽  
Current Status ◽  
Controversial Issues ◽  
Mechanisms Of Resistance ◽  
Pyrethroid Insecticides ◽  
Global View ◽  
The Status

The status of resistance to organophosphate, carbamate, cyclodiene and pyrethroid insecticides in the heliothine Lepidoptera is reviewed. In particular, resistance in the tobacco budworm, Heliothis virescens , and the corn earworm, Helicoverpa zea , from the New World, and the cotton bollworm, Helicoverpa armigera , from the Old World, are considered in detail. Particular emphasis has been placed on resistance to the most widely used of these insecticide groups, the pyrethroids. In each case, the incidence and current status of resistance are considered before a detailed view of the mechanisms of resistance is given. Controversial issues regarding the nature of mechanisms of resistance to pyrethroid insecticides are discussed. The implications for resistance management are considered.

scholarly journals Phytotoxicity and Pollination Disorders in Sweet Corn Due to Direct-silk Applications of Materials Used for Alternative Corn Earworm Control

2007 ◽  
Vol 17 (2) ◽  
pp. 163-168 ◽  
Author(s):  
Tori Lee Jackson ◽  
Mark G. Hutton ◽  
David T. Handley
Keyword(s):  
New England ◽  
Helicoverpa Zea ◽  
Sweet Corn ◽  
Corn Oil ◽  
Corn Earworm ◽  
Soy Oil ◽  
Conventional Management ◽  
Repeated Applications ◽  
Materials Used ◽  
Significant Injury

Corn earworm [CEW (Helicoverpa zea)] is one of the most important pests of sweet corn (Zea mays) in New England. Conventional management of this pest is achieved through repeated applications of chemical insecticides through the silking period. Organic growers, however, have few alternatives to prevent CEW infestation. Technology first developed in the 1930s and 1940s, using applications of mineral oil directly into the silk channel with an eyedropper, has been further researched in recent years using vegetable oils with and without pesticides, but pollination problems associated with these treatments have been observed. Several materials were evaluated for efficacy in controlling CEW populations and for phytotoxicity to the developing ear. Materials evaluated were corn oil, soy oil, carrageenan, corn oil mixed with Bacillus thuringiensis ssp. kurstaki (Bt), soy oil mixed with Bt, and carrageenan mixed with Bt. All treatments were compared with an untreated control. Treatments provided a range of 33% to 50% control of CEW infestation. The oil and Bt combinations provided some reduction in infestation compared with the untreated controls (33% vs. 100% infestation), but this level of control was inadequate for all wholesale markets and most direct markets. Additionally, oil-based treatments also caused significant injury to developing ears by reducing pollination quality, impacting the development of the kernels at the ear tip. This condition referred to as “cone-tip” is of concern since it may decrease marketability. The percent unmarketable ears due to cone-tips ranged from 0% to 13% for the untreated and carrageenan-based treatments. From 12% to 42% of ears were unmarketable due to the soy oil treatments. Corn oil treatments caused 10% to 50% cone-tips.

Field Bioassay of Pheromone Lures and Trap Designs for Monitoring Adult Corn Earworm (Lepidoptera: Noctuidae) in Sweet Corn in Southern New England

1920 ◽  
Vol 17 (3) ◽  
pp. 1833-1836
Author(s):  
Norman L. Gauthier ◽  
Patrick A. Logan ◽  
Lisa A. Tewksbury ◽  
Craig F. Hollingsworth ◽  
Donald C. Weber ◽  
...  
Keyword(s):  
New England ◽  
Rhode Island ◽  
Helicoverpa Zea ◽  
Sweet Corn ◽  
Corn Earworm ◽  
Reference Standards ◽  
Fresh Market ◽  
Field Bioassay ◽  
Southern New England ◽  
Lepidoptera Noctuidae

Four commercial pheromones attractive to Helicoverpa zea (Boddie) were used as baits in four insect traps to attract moths in fresh market sweet corn. Moth catches were monitored for 10 wk in nine sites in Connecticut, Massachusetts, and Rhode Island. Zealure attracted twice as many moths as Scentry's corn earworm lure and nine times as many as Pherocon's corn earworm lure. Consep Membrane's Biolure attracted few moths. Hartstack traps caught three times more moths than Heliothis net traps and 15 times more than Multi-pher or International Pheromone Systems traps. Results suggest the need for reference standards in management programs that use pheromones to monitor corn earworm populations.

Alternatives to Pyrethroids for Managing Corn Earworm in Sweet Corn, Seed Corn, Tomatoes and Peppers

2007 ◽  
Vol 8 (1) ◽  
pp. 60 ◽  
Author(s):  
Richard Weinzierl
Keyword(s):  
Management Practices ◽  
Potential Problem ◽  
Sweet Corn ◽  
Commercial Production ◽  
Corn Earworm ◽  
Current Status ◽  
Pyrethroid Insecticides ◽  
Corn Seed ◽  
Seed Corn ◽  
Management Alternatives

To date, there are no reports of widespread failures of pyrethroid insecticides to control the corn earworm in midwestern North America. However, H. zea resistance to pyrethroids is a potential problem. If resistance compromises pyrethroid effectiveness, adopting or developing alternative management practices will be essential. This paper summarizes the current status of management alternatives for H. zea, specifically in commercial production of sweet corn, seed corn, tomatoes, and peppers. Accepted for publication 26 October 2006. Published 19 July 2007.

scholarly journals Direct Silk Applications of Corn Oil and Bacillus thuringiensis as a Barrier to Corn Earworm Larvae in Sweet Corn

2003 ◽  
Vol 13 (3) ◽  
pp. 509-514 ◽  
Author(s):  
Rosalind Cook ◽  
Anne Carter ◽  
Pam Westgate ◽  
Ruth Hazzard
Keyword(s):  
Bacillus Thuringiensis ◽  
Helicoverpa Zea ◽  
Sweet Corn ◽  
Corn Oil ◽  
Field Studies ◽  
Corn Earworm ◽  
Untreated Plot ◽  
Promising Alternative ◽  
First Instar ◽  
Almost All

Field studies were conducted in 2000 and 2001 to rate the efficacy and longevity of four pesticide treatments against corn earworm (Helicoverpa zea) larvae (CEW) in sweet corn (Zea mays). The four treatments used were 1) corn oil, 2) Bacillus thuringiensis ssp. kurstaki (Bt), 3) oil + Bt, and 4) an untreated plot. All treatments were applied on silk day 5. Silk day 1 was the first day that more than 50% of the ears had 2.5 cm (1 inch) or more silks emerging from the husk using a hand-held pump applicator. Two first-instar CEW larvae were placed directly into silk channel of selected ears on 6 different days (days 3, 6, 9, 12, 15, and 18 after first silk). The same six ears were then harvested 4 days later. Untreated ears had more live CEW and higher levels of feeding damage than the other three treatments ears for all harvest days in both years. The number of CEW found per ear was lower when Bt was included in the treatment. The use of corn oil gave the lowest damage ratings on almost all harvest days in both years. Treatments which contained oil had the highest number of marketable ears in both years, but also the highest percentage of underdeveloped kernels at the tip of the ear (6% to 9%). The oil and Bt treatments appeared to control CEW for at least 17 days, from silking through maturity. This treatment regime appears to be a promising alternative for growers to conventional pest management methods.

scholarly journals Combining Ability of Husk Extension, Maysin Content, and Corn Earworm Resistance

2021 ◽  
Vol 146 (1) ◽  
pp. 14-23
Author(s):  
Virginia M. Moore ◽  
William F. Tracy
Keyword(s):  
Zea Mays ◽  
Combining Ability ◽  
Helicoverpa Zea ◽  
Sweet Corn ◽  
Corn Earworm ◽  
Management Options ◽  
Mating Design ◽  
Cultivar Development ◽  
Factorial Mating ◽  
Factorial Mating Design

Corn earworm (Helicoverpa zea) is a destructive pest with limited management options in sweet corn (Zea mays) production. Increased husk extension and the presence of the C-glycosyl flavone maysin are two proposed mechanisms for improving corn earworm resistance in corn cultivars. A factorial mating design was conducted to test hybrid combinations of sweet corn inbreds with long husks and/or maysin to identify candidates for future cultivar development. The mating design had seven male parents, including three commercial sweet corn inbreds (Wh9261, We11401, and Wt1001) and four inbreds selected for maysin content (Maysin1, 2, 3, and 4), and five female parents, including two commercial sweet corn inbreds (Ia453su and Ia5125su) and three inbreds with long, thick, tight husks (A684su, A685su, and A686su). Hybrids were evaluated for ear length, husk length, maysin content, and corn earworm resistance at six environments in 2016 and 2017. Relationships between husk extension, maysin, and corn earworm resistance were inconsistent, but five inbreds produced hybrids with significantly lower corn earworm infestation and/or damage, demonstrating potential to confer resistance to the corn earworm.

scholarly journals Maize silk antibiotic polyphenol compounds and molecular genetic improvement of resistance to corn earworm (Helicoverpa zea Boddie) in sh2 sweet corn

2010 ◽  
Vol 1 (1) ◽  
pp. 3 ◽  
Author(s):  
Baozhu Guo ◽  
Ana Butrón ◽  
Brian T. Scully
Keyword(s):  
Helicoverpa Zea ◽  
Sweet Corn ◽  
Gene Action ◽  
Molecular Genetic ◽  
Pleiotropic Effect ◽  
Corn Earworm ◽  
Critical Factors ◽  
Polyphenol Compounds ◽  
Field Corn ◽  
Antibiotic Compounds

The flavor of sh2 super-sweet corn is preferred by consumers. Unfortunately, sh2 sweet corn has little genetic variation for insect resistance. In this paper we review the functions of two loci, p1 and a1. The P1 allele has a major role in sh2 sweet corn resistance to corn earworm, an allele that was lost in historical selection because of its pleiotropic effect on undesirable cob color and silk browning. The P1 allele has significant effects on biosyntheses of silk antibiotic compounds, maysin, apimaysin, methoxymaysin, and chlorogenic acid. The effect of a1 shows gene action for lowered maysin and significant epistatic action with p1. The dominant functional allele A1 causes anthocyanin pigments in aleurone, plant, and pericarp tissues; the recessive a1 allele causes absence of pigment in these tissues. If silk browning and cob color are critical factors for maysin production but lack the customer’s preference, then separating red cob and browning silk, which are controlled by the P1 allele, may be difficult if not impossible. One high silk maysin sh2 sweet corn germ­plasm, shrunken Zapalote Chico, has been released. There is some field corn germplasm with p1-wwr alleles, but the amount of antibiotic flavones and their potential as a donor need further investigation.

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