Control Of European Corn Borer Research Articles

Transgenic Corn for Control of the European Corn Borer and Corn Rootworms: a Survey of Midwestern Farmers’ Practices and Perceptions

In 2001, a self-administered questionnaire was sent to 1000 corn, Zea mays L., farmers in each of five states (Illinois, Indiana, Iowa, Minnesota, and Nebraska) to evaluate their perceptions of transgenic corn designed to control the European corn borer, Ostrinia nubilalis (Hübner), and corn rootworms, Diabrotica spp. Respondents returned 1,313 surveys (26.2%). Farmers with small acreages planted a greater portion of their corn (54.5%) with transgenic corn for control of European corn borer than farmers with large farms (39.2%). The majority (75.2%) of farmers use crop rotation to control the corn rootworm. Nine insecticides comprised 92.2% of the commercial soil insecticides used for control of corn rootworm larvae. More than one-third of the farmers in Illinois (33.5%) and Indiana (39.4%) treated first-year corn for corn rootworm, primarily due to western corn rootworm egg laying in soybean, Glycine max (L.). When asked whether they would plant transgenic corn protected against the corn rootworm, 35.0% of farmers responded they would, whereas 40.5% said they were unsure. The two greatest farmer concerns about transgenic corn were the ability to sell harvested grain (59.3%) and additional technology fees (54.8%). Respondents indicated that less farmer exposure to insecticide (69.9%) and less insecticide in the environment (68.5%) were the primary benefits of transgenic corn. Farmers who had no concerns about transgenic corn for rootworm control were more likely to purchase the product (46.8%). The most common refuge-planting options farmers favored were adjacent fields (30.9%) and split fields (29.9%). Farmers (21.1%) observed a yield increase (23.7 bu/ha [9.6 bu/acre]) when using transgenic corn for European corn borer control compared with non-transgenic corn. These data can help in understanding farmers' knowledge and concerns regarding transgenic corn. This information may be of value to guide researchers, extension specialists, and policy makers in designing insect resistance management and integrated pest management programs.

Controlling European corn borer in vegetables with a parasitic wasp

Thomas P. Kuhar (Department of Entomology, Virginia Tech), Michael P. Hoffmann (Department of Entomology, Cornell University), and Mark G. Wright (Department of Plant and Environmental Protection Sciences, University of Hawaii) summarize current reasearch with Trichogramma ostriniae for control of European corn borer in vegetable crops.

Biotechnology and the European corn borer: measuring historical farmer perceptions and adoption of transgenic Bt corn as a pest management strategy.

A 3-yr, multi-state survey of farmers who had planted transgenic Bacillus thuringiensis (Bt) corn was conducted to evaluate perceptions of Bt corn performance and its utility as a management option for European corn borer, Ostrinia nubilalis (Hübner). A questionnaire was sent to farmers in Illinois, Iowa, Kansas, Minnesota, Nebraska, and Pennsylvania who had grown Bt corn during the growing seasons of 1996, 1997, or 1998. There were 7,427 usable questionnaires returned with the following response percentages: 1996 (42.1%), 1997 (35.0%), and 1998 (22.6%). Adoption rates, based on percentage of acreage planted to Bt corn, increased dramatically from 1996 (10.5%) to 1998 (40.7%). The states growing the highest percentage of Bt corn were Minnesota, Iowa, and then Nebraska However, Illinois, was adopting Bt corn at the fastest rate. Historical use of insecticides did not influence the adoption of Bt corn. In addition, of those farmers who used insecticides to control European corn borer, the percentage that decreased their use of insecticides nearly doubled from 13.2% (1996) to 26.0% (1998) over this 3-yr period. The primary reason farmers planted Bt corn was to eliminate the yield loss caused by European corn borer. Scouting for European corn borers decreased from 91% (scouting 2.2 times a year) in 1996 to 75% (scouting 1.8 times a year) in 1998. The percentage of farmers not scouting for European corn borers increased from 9.6% (1996) to 25% (1998). Most farmers believed yields of Bt hybrids were either similar to or greater than the yields of non-Bt hybrids. Minnesota farmers perceived the greatest yield advantages. Farmers are becoming more aware of insect resistance management guidelines; however, they also clearly show preferences for having the flexibility to use different spatial plantings of Bt and non-Bt corn. Finally, after having planted Bt corn and obtained excellent control of European corn borer, most farmers believed that this insect had been causing more yield loss than they previously had suspected in their non-Bt corn. The data represented here provide an historical foundation for how transgenic Bt corn was used by farmers during the first 3 yr of commercial availability, their initial perceptions on the performance of this technology, and their attitudes regarding management of the European corn borer.

Insect management and herbicide tolerance in near-isogenic sister lines of transgenic and non-transgenic sweet corn

Pest management systems were evaluated in three near-isogenic lines of transgenic and non-transgenic sweet corn. The genetic transformation was reputed to confer resistance to corn earworm ( Helicoverpa zea) and European corn borer ( Ostrinia nubilalis), and increase tolerance to the herbicide glufosinate. Plots were planted with either a transgenic line or a non-transgenic sister line. Transgenic and non-transgenic varieties were treated with a herbicide; either glufosinate or bentazon, respectively, applied post-emergence. Ears of the non-transgenic varieties were protected by spraying insecticides every 3–4 days. Transgenic varieties were not sprayed. Glufosinate caused temporary chlorosis (5% or less) and stunting (6% or less) of transgenic sweet corn in one experiment. Bentazon did not injure non-transgenic varieties. Corn earworm and European corn borer control in transgenic sweet corn was superior to that achieved in non-transgenic varieties sprayed with insecticides. Damaged ears of transgenic varieties ranged from 0% to 6% and most damage was restricted to the tip of the silk end. A few small, moribund larvae were recovered. In contrast, 40% of non-transgenic varieties, on average, had damaged ears, despite regular spraying of insecticides. Ears of non-transgenic varieties were damaged more severely and many late-instar larvae were recovered.

Corn Earworm and European Corn Borer Control with Insecticides, 1997

Abstract ‘Golden Queen’ sweet corn was seeded on 22 I Apr near Calabash, NC in Brunswick Co. Single-row plots, 10 ft long on 42-inch centers, were replicated 4 times in a RCB design. Alleys of 5 ft were used I between replicates. Treatments were applied with a CO2-pressurized backpack sprayer using a single hollow-cone nozzle (18X) operating at 60 psi to deliver 54.5 gpa. Test 1 and Test 2 were in the same field with a 75 ft spacing of untreated area between the two test sites. Applications were made to both Test 1 and Test 2 twice a week on 27 and 30 Jun, and 3, 7, 10, 14, and 17 Jul. Insect-damaged ears were assayed on 21 Jul when all ears were harvested from both tests.

Insecticide Rescue Treatments for Control of First-Generation European Corn Borer in South Dakota, 1997

Abstract Corn fields near New Holland and Letcher, South Dakota were used to evaluate planting-time and postemergence insecticides for controlling first-generation European corn borer, Ostrinia nubilalis Hubner, larvae. Preapplication counts (4 d before application) at Letcher indicated a uniform infestation of O. nubilalis larvae in 92.0% of plants sampled. Approximately 2.4 larvae (4.2, 62.5 and 33.3% were 1st, 2nd and 3rd instars, respectively) per plant were observed at this location. Similarly at New Holland a 90% infestation level (predominantly 1st and 2nd instars on the application date) existed, but the average number of larvae was estimated to be ~ 4-fold less than at Letcher). The at-planting-time treatment at New Holland occurred on 15 May and all whorl-treatments (approximately 1 week prior to tasseling) on 12 July (Letcher) and 15 July (New Holland). Insecticides were applied to single-row plots (16.4 cm by 30.5 m) in a randomized complete block design with 4 replicates. Granules were directed into corn plant’s whorl using a pneumatic applicator powered by a 3.5-horsepower engine mounted on a highboy. Noble metering units attached to a modified chain-driven apparatus regulated the amount of granules released into the pneumatic applicator. Liquid treatments were applied to corn plant whorls using a single-nozzle 3-gal. CO2-propelled backpack sprayer system. Approximately one month following insecticide applications (11 August), twenty corn stalks were randomly chosen from each plot. Each plant was split vertically and examined for O. nubilalis tunneling damage. The number and length of O. nubilalis cavities were analyzed using the ANOVA procedure with means being compared with the LSD.

Control of Second-Generation European Corn Borer, 1997

Abstract Foliar treatments of registered and non-registered insecticides for second-generation European corn borer control were applied to irrigated corn plots in Dixon County, NE on 12 Aug. Liquid-formulated insecticides were applied with a Hahn Hi-Boy calibrated to deliver 17 gpa at 30 psi. Four d prior to application, 6 black-headed egg masses on paper disc were pinned to the middle portion of 10 marked com plants in each replicate. Experimental design was RCB with 4 replications. On 25 Sep, the infested plants were dissected from tassel to ground, examined and the number of corn borer larvae recorded. Results were analyzed using analysis of variance procedures. Treatment means were separated using LSD procedures.

Reduced Fusarium Ear Rot and Symptomless Infection in Kernels of Maize Genetically Engineered for European Corn Borer Resistance

ABSTRACT Field experiments were conducted in 1994, 1995, and 1996 to evaluate the incidence and severity of Fusarium ear rot and the incidence of symp-tomless Fusarium infection in kernels of maize hybrids genetically engineered with Bacillus thuringiensis genes encoding for the delta-endotoxin CryIA(b). Treatments included manual infestation with European corn borer (ECB) larvae and insecticide applications to limit ECB activity to specific maize growth stages or mimic standard ECB control practices. Fusarium symptoms and infection were affected by the specific cryIA(b) transformation used in each hybrid that determines tissue-specific expression of CryIA(b). In hybrids expressing CryIA(b) in kernels, incidence and severity of Fusarium ear rot and incidence of symptomless kernel infection were reduced compared with near-isogenic hybrids lacking cryIA(b) genes. In plants that were manually infested with ECB, ear rot incidence was reduced by 87, 58, and 68%; severity was reduced by 96, 54, and 64%; and incidence of kernel infection by Fusarium species was reduced by 17, 38, and 38% in 1994, 1995, and 1996, respectively. Results were similar in treatments that were not manually infested, but differences between transgenic and nontransgenic hybrids were smaller. Most kernel infection was due to F. moniliforme, F. proliferatum, and F. subglutinans (section Liseola) collectively, and it was within this group that transgenic hybrids exhibited reduced infection. Expression of CryIA(b) in plant tissues other than kernels did not consistently affect Fusarium symptoms or infection. Disease incidence was positively correlated with ECB damage to kernels. Insecticide applications also reduced Fusarium symptoms and infection when applied to nontransgenic plants.

The Ecology of Agricultural Pests: Biochemical Approaches.

Introduction. Biochemical systematics: principles and perspectives for pest management. Combined use of biochemical, immunological and molecular assays for infection, species identification and and resistance detection in field populations of Anopheles (Diptera: Culicidae). Studies of interactions between alfalfa weevil strains, Wolbachia endosymbionts and parasitoids. Biochemical approaches to the study of ecological genetics: the role of selection and gene flow in the evolution of insecticide resistance. A molecular and ecological investigation of the large arionid slugs of north west Europe: the potential for new pests. Systematics of brown planthopper and related species using nuclear and mitochondrial DNA. Application of novel molecular markers (DNA) in agricultural entomology. Location of resistance to Brevicoryne brassicae in wild brassica species. The use of DNA markers in population genetics and ecological studies of the desert locust Schistocerca gregaria (Orthoptera: Acrididae). The use of DNA analysis and the polymerase chain reaction in the study of introduced pests in New Zealand. Serological analysis of arthropod predation: past, present and future. Serological diagnosis of parasitism: a monoclonal antibody-based immunodot assay for Microplitis (Hymenoptera: Braconidae). Polyclonal, monoclonal and engineered antibodies to investigate the role of predation in slug population dynamics. The potential of combinatorial antibody libraries in pest/predator relationship studies. Serological analysis of predators of Helicoverpa armigera Hubner (Lepidoptera: Noctuidae) eggs if sorghum-pigeonpea intercropping at ICRISAT, India: a preliminary field study. Using gut content immunoassays to evaluate predaceous biological control agents: a case study. An environmental risk assessment for release of an exotic microsporidium for European corn borer control in North America. Progress in quantifying predation using antibody techniques. Electrophoretic approaches to predator-prey interactions. Genetics of esterases in laboratory and feral cotton boll weevils, Anthonomus grandis Bohemia. Practical applications for techniques to determine the nutritional state and age of field caught tsetse flies.

Efficacy of Registered and Experimental Insecticides for Control of European Corn Borer Under Artificial Infestation, 1996

Abstract Corn was planted at the Shaw Foundation Farm, Champaign, IL in rows 30 inches wide on 17 Jun. A RCB design was used, and each treatment was replicated four times. Two untreated controls were used per replication and averaged for the analysis. Each plot was 4 rows wide X 60 ft long. Insecticides were applied to the middle 2 rows of each plot; the 2 outside rows were left untreated. Treatments were applied with a modified John Deere 6000 high-clearance vehicle (HCV) with a rear-mounted boom. Granules were applied through Noble units mounted in brackets on the rear of the HCV. The Noble units were driven with electric motors, and the granules were applied over the whorls in a 7-inch band. Liquid insecticides were broadcast over the center 2 rows of the 4-row plot with TeeJet even fiat-fan spray tips (8003VS) mounted in brackets on the rear of the HCV. The height of the nozzles was approximately 18 inches above the whorls. The liquids were delivered with a compressed-air system calibrated to deliver 11.0 gpa at 20 psi at a speed of 2.5 mph. Plants were artificially infested with ECB on 18 and 19 Jul. Two black head stage ECB egg masses were placed in the whorl of 15 consecutive plants in each of the middle 2 rows of a 4-row plot on each of the 2 infestation dates. On 26 Aug, 10 of the infested plants from each of the middle 2 rows in each plot were split with a corn knife for evaluation. The number of borer cavities and the total length of cavities per plant were recorded. The mean percentage of plants with cavities and percent control were determined for each treatment.

Control of European Corn Borer in Whorl Stage Corn, 1996

Abstract The experimental design was RCB with 20 insecticide treatments and an untreated check replicated four times. Single-row plots were 50 ft in length and at 30 inch spacings. Corn was no-till planted into soybean residue on 29 Apr. All granular insecticides were applied in a seven inch band over the whorl with a specially designed cone belt distributors mounted on a Hahn Hi-boy. The distributors were also mounted on the plantar for the in-furrow treatment of Regent 3G applied at planting. Liquid insecticides were applied with a back-pack sprayer directing the spray solution into the whorl and calibrated to deliver 18 gpa at 30 psi, excepting Regent 80WG which was applied in-furrow at planting time. The planting time in-furrow treatment was applied as 1.0 gpa spray solution. On 27 Jun, six black headed ECB egg-masses were placed in each whorl often marked plants per plot row. Whorl treatments were applied 6 days later on 3 Jul, excepting a treatment of regent 80WG which was applied to eight-inch corn on 14 Jun. On 30 Jul, the 10 marked plants in each replicate were dissected from tassel to ground, examined and the number of corn borer cavities recorded.

Colorado Potato Beetle and European Corn Borer Control with Insecticides, 1996

Abstract ‘Atlantic’ potatoes were | planted by the grower in early Mar near Elizabeth City, NC and in late Mar at McGees Crossroads (MGX) near Benson, N.C. The test plots were each 20 ift. long, with single-row spacing on 42 inch centers and a guard row between treatments. The tests at both locations were replicated 4 times in a RCB design. Alleys of 10 ft, perpendicular to rows, were used between replicates in Test 1 (Pasquotank Co., Elizabeth City, NC) and 5 ft. alleys were used in Test i2 (Johnston Co., MGX). Treatments were applied with a CO2 pressurized backpack sprayer with a single hollow cone nozzle (18X) operating at 60 psi to J deliver 54.5 gpa. In Test 1, potatoes were uncovered and Admire 2F was applied over the top on 25 Mar and in Test 2, on 26 Mar. Both tests received Admire 2F at the rate of 1.0 fluid oz per 1000 linear ft of row. Provado 1.6F was applied at CPB egg stage only on 6 May for Test and on 22 May for Test 2. All other treatments were applied on 13 May for Test 1 and on 22 and 28 May for Test 2 when small larvae were present. Test 1 apparently received an overspray of Provado for CPB by the grower and we were unable to make any weekly CPB counts or ratings. Counts of CPB on 3 hills/plot as well as visual damage ratings were made on 28 May and 4 Jun for Test 2 at MGX. Small larvae were assumed to be first and second instar, and large larvae, third and fourth instar. Counts of entry points of ECB for the entire row were taken on 11 Jun for Test 1 and on 12 Jun for Test 2. Due to grower error, no yield data were obtained in Test 1. In Text 2, potatoes were harvested on 10 ft of row to measure yields at 12 Jun.

Control of Second Generation European Corn Borer, 1996

Abstract Foliar treatments of registered and non-registered insecticides for second generation ECB control were applied to irrigated corn plots in Dixon County, NE on 16 Aug. Liquid formulated insecticides were applied with a Hahn Hi-Boy calibrated to deliver 17 gpa at 30 psi. Two days prior to application, six black headed egg masses on paper disc were pinned to the middle portion of 10 marked corn plants in each replicate. Experimental design was RCB with four replications. On 27 Sep, the infested plants were dissected from tassel to ground, examined and the number of corn borer larvae recorded. Results were analyzed using analysis of variance. Treatment means were separated using LSD procedures.

Sequential Sampling Plans for Use in Timing Insecticide Applications for Control of European Corn Borer (Lepidoptera: Pyralidae) in Potato

Sequential sampling plans were developed for use in recommending control of European corn borer, Ostrinia nubilalis (Hubner), in potato, Solanum tuberosum L., fields based on the distribution of damaged stems. Likelihood ratio tests indicated that the beta-binomial distribution (aggregated) provided a better fit than the binomial (random) when the mean percentage of damaged stems in a field was ≥6%, but not when damage was <6%. Similarly, variance-ratio ( D ) and C ( a ) tests indicated that damage was aggregated generally at damage levels ≥6%. Because the slope ( b ) ± SEM of the binary form of the Taylor power law (1.15 ± 0.05) (total of 41 fields) revealed moderate overdispersion, and a weak linear relationship existed between the index of aggregation ( θ ) and p , sequential sampling plans were evaluated under various degrees of aggregation. The precision and practicality of the sequential sampling plans were evaluated through calculation of operational characteristic and average sample number functions for both simulated binomial and beta-binomial distributions. Precision of the sequential sampling plans decreased as the aggregation of O. nubilalis damage increased, especially when the proportion of damaged stems was near threshold. However, needed to make the decision.

Evaluation of Corn Rootworm Insecticide Treatments and Carry-Over Control of European Corn Borers in South Dakota, 1995

Abstract A secondary benefit of corn rootworm insecticide treatments could be the residual control of European corn borer (ECB) larvae. Our study was repeated at sites near Aurora, Cavour, Delmont, and Garretson, South Dakota to assess the efficacy and secondary ECB control provided by 3 insecticides (Furadan, 60720A, &amp; Regent). Treatment plots consisted of single 15.2 m long rows which were spaced 96.5 cm apart. The study was arranged in a RCBD with 4 replicates at each site. Granular insecticide formulations were applied with modified Noble metering units mounted on a specially adapted Kinze 4-row com planter. Metering units were ground-driven, and all units were calibrated on the planter before applications. Banded (B) insecticide treatments were applied in an 18-cm swath over the open seed furrow in front of furrow-closing wheels (T-band), and were incorporated by the wheels and drag chains. In-furrow (F) treatments were placed directly between double-disk furrow openers and into the open seed furrow. Cultivation-time liquids were applied using a CO2-powered backpack canister sprayer system equipped with a single nozzle (Teejet 8003 flat fan) hand-held boom. The system was calibrated to deliver 20 gpa. To evaluate rootworm damage 5 roots per replicate were dug for each treatment. Roots were washed, examined for corn rootworm larval feeding damage, and rated in accordance with the Iowa 1 to 6 scale. For assessment of ECB control, 10 com stalks were randomly chosen from each plot. Plants were split vertically and examined for corn borer tunneling damage. The number and length of ECB cavities were analyzed along with root injury data using SAS’s General Linear Models (GLM) procedure and means were compared by DMRT.

Control of European Corn Borer in Whorl Stage Corn, 1995

Abstract The experimental design was RCB with 22 insecticide-treatments and an untreated check replicated 4 times. Single row plots were 50 ft in length and at 30 inch spacings. Corn was no-till planted into soybean residue on 16 May. Granular insecticides were Applied in a 7-inch band with cone belt distributors mounted on a Hahn Hi-Boy. Liquid insecticides were applied with a back-pack sprayer in 20 gpa at 30 psi on 12 Jul. Five d prior to insecticide application 6 black headed ECB egg masses were placed on 10 marked plants/replicate for later evaluation. On 3 Aug, the marked plants in each replicate were dissected from tassel to ground, examined and the number of corn borer cavities recorded.

Aerial Application of Insecticides for Control of First Generation European Corn Borer, 1995

Abstract The cornfield was located in Cedar County, northwest of the town of Hartington, NE. Two treatments and an untreated check were arranged in a strip plot design with one replication. Six black headed egg masses were infested onto 30 marked plants (3, ten plant subsamples) per treatment on 6 Jul. A Cessna 188 Ag Truck was used to make the applications on 13 Jul. On 18 Aug, all artificially infested plants were disected from tassel to ground and examined for corn borer cavities. Data were analyzed using analysis of variance procedures. Treatment means were separated using LSD procedures.

Control of Second Generation European Corn Borer, 1995

Abstract Foliar treatments of registered and non-registered insecticides for second generation European corn borer were applied to irrigated corn plots in Dixon County, NE on 9 Aug. Liquid formulated insecticides were applied with a Hahn Hi-Boy calibrated to deliver 17 gpa at 30 psi. Granular formulated insecticides were applied with Noble granulator units mounted on the same Hahn Hi-Boy with 10 inch row banders. Twenty-four hr prior to application, 6 black headed egg masses on paper disc were pinned to the middle portion of 10 marked corn plants in each replicate. Experimental design was RCB with 4 replications. On 14 Sep, the infested plants were dissected from tassel to ground, examined and the number of corn borer larvae recorded. Results were analyzed using analysis of variance produres. Treatment means were separated using LSD procedures.

Laboratory Activity of Spinosad on the European Corn Borer 1994

Abstract To evaluate the European corn borer control of spinosad, the first example of the naturalyte insect control class, two techniques were utilized. First, corn seedlings were cut and confined with spinosad corn cob granules in a 150 mm petri dishes with corn borer eggs and a moist dental wick. For each material, four replicates per rate and 4 rates were evaluated after 10 days. The amount of feeding present in the dishes was scored and compared to the untreated to determine percent control. After activity was seen in these preliminary tests, a more field correlated study was run utilizing large whorl stage (18“) corn plants previously infested with egg masses of European corn borer. The plants were treated in the whorl with various granular treatments at the shot-holing stage approximately 2 weeks following infestation. After 3 weeks in the greenhouse, the corn stalks were split and the number of larvae and the length of the tunnels were recorded. These were compared to the untreated check to obtain percent control.

Evaluation of Peruvian Maize for Resistance to European Corn Borer (Lepidoptera: Pyralidae) Leaf Feeding and Ovipositional Preference

Partial control of the European corn borer, Ostrinia nubilalis (Hubner), in maize, Zea mays L., has been achieved through germplasm resistant to leaf feeding that was incorporated into breeding populations. Leaf-feeding resistance to European corn borer in maize had generally been attributed to presence of the chemical 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA). New sources of resistance, other than that mediated by DIMBOA, are desirable for developing new resistant cultivars. From 1990 to 1992, 1,601 accessions of Peruvian maize maintained in the U.S. National Plant Germplasm System were evaluated for leaf-feeding resistance to European corn borer. Eleven resistant accessions were identified, all of which originated from Peru's north coast. The 11 resistant accessions were then analyzed for 6-methoxybenzoxazolinone (MBOA), the degradation product of DIMBOA and an indicator of DIMBOA levels present in the plant. All 11 resistant accessions contained low MBOA concentrations, equivalent to that found in the susceptible inbred WF9, indicating that DIMBOA is not the basis of this resistance. The factor(s) underlying this source of host plant resistance remains to be determined. Six morphologically diverse Peruvian maize races were evaluated in the greenhouse for ovipositional nonpreference by the European corn borer. Some differences were noted, but morphological factors could not be confirmed as causing the differences.