Control Of Fall Armyworm Research Articles

Seed Treatment and Foliar Insecticidal Control of Fall Armyworm in Florida Sweet Corn, 1991

Abstract Three raised, plastic-mulched beds on 1.8 m centers were divided into 4 replicate blocks. Each block was comprised often 4.3 m single-row plots separated by 0.6 m of buffer space. Five randomly selected plots in each block were planted on 28 Oct with three seed per planting hole spaced every 25 cm in double rows 25 cm apart. Remaining plots were planted with seed from the same lot which had been treated just prior to planting with Larvin 3.2, by mixing a small amount of seed with sufficient chemical to give a treatment rate of 1.4 L per 100 lbs seed. The number of seedlings was noted and plants were thinned to one stalk per planting hole. Five post-planting treatments were assigned randomly to the two seed treatment categories in each block. Beginning 11 Nov, plants were evaluated positive or negative for feeding damage to the whorl and 2 uppermost leaves.

Selected Insecticide Evaluations for Control of Fall Armyworm in Peanut, 1992:

Abstract Selected insecticides were evaluated against FAW in Virginia-type peanut in Greensville County, VA. Peanuts were planted 15 May using a 36-inch row spacing. Test treatments were applied on 24 Aug using a CO2 pressurized backpack sprayer calibrated to deliver 14.5 gal/acre at 50 psi through 3, D2-13 disc-core hollow cone spray nozzles per row, 1 over the top and 1 on each side. A RCB experimental design was used with 4 replicates; plots were 4 rows by 30 ft. Treatments were evaluated before and 1 and 4 DAT by comparing numbers of small, medium, and large-sized FAW larvae per 3 row ft, corresponding to lst-2nd, 3rd-4th, and 5th-6th instar groupings, respectively. A standard or rigid beat cloth was used in each plot to determine number of worms per 3 row ft. Data were analyzed using ANOVA and LSD procedures.

Insecticidal and Biological Control of Fall Armyworm in Florida Sweet Corn, 1991

Abstract Sweet corn was planted on 10 Sep with 10 in. between plants in double rows spaced 10 inches apart on raised beds mulched with polyethylene film. Three 240 ft beds on 6 ft centers were divided into four replicate blocks, containing nine, 15 ft single row treatment plots and one, 15 ft control plot (5 ft per row). One neonate fall armyworm was placed in each leaf whorl 1 week prior to treatment. Six weekly applications were made beginning on 2 Oct. Biosafe (nematodes) was applied the first 3 weeks only, followed by Lannate on subsequent dates. The first Biosafe application was made by automatic pipette to the whorl (into which 3.5 g of washed sand had already been introduced in treatment 3), and subsequently by hand-held trigger sprayer. Dipel 10 G was applied directly to the whorl from pre-weighed cups for the first two applications, followed by spray applications with Dipel 2 X. Remaining applications were made with a CO2 pressurized sprayer at a tank pressure of 40 psi, timed to deliver 100 gal/acre.

Control of Fall Armyworm on Whorl Stage Corn, 1991

Abstract Sweet corn was planted on 3 Jul near Georgetown, DE. Four row plots, 20 ft long on 30 inch centers, were replicated 4 times in a randomized complete block design. Treatments were applied with a CO2 pressurized wheel barrow sprayer using one nozzle/row delivering 26.4 gal/acre at 40 psi. Treatments were applied on 6 Aug. All plant whorls were removed from the center 2 rows from each plot, unrolled and the numbers of infested plants counted 13 Aug.

Control of Corn Earworm and Fall Armyworm in Sweetcorn, 1991

Abstract Funks G80' sweetcorn was planted on 11 Jun at the University of Georgia Plant Sciences Farm, Oconee Co. A randomized complete block design was used with 2-row plots, 20 ft long with 38 in row width, 3 ft alleys and 5 replicates. Plants were treated with a full cone sprayer using a CO2 pressure sprayer at 30 psi with a final volume of 25 gal/acre directed on the plant ears. Sprays were applied 10 times beginning prior to silking on 24 Jul, and continuing on 26, 29, 31 Jul, 2, 5, 7, 9, 12, and 14 Aug. All ears in the center 16 ft of row were examined on 15 Aug for the presence of larvae or damage.

Influence of Three Types of Borders on Field Evaluation of Insecticides for Fall Armyworm (Lepidoptera: Noctuidae) Control in Seedling Corn2

The performance of insecticides when applied against the fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), larvae in whorl stage corn was studied in relation to larval movement within and between test plots. The effectiveness of individual treatments varied in accordance with their toxicity to FAW. The degree of FAW suppression was critically influenced by the type of adjacent treatment (Exp 1). Side-by-side experimental plots with no borders gave results that made better performing insecticides look worse than they were, while poorer performers looked better. Plots having fallow (tillage only), untreated, and insecticide-treated borders (Exp 2) contained 21, 14, and 9% dead plants, respectively, from FAW feeding. Methomyl and monocrotophos gave the greatest control of FAW larvae, while trichlorfon and carbaryl were the least effective insecticides. Permethrin gave poor control with one application but improved with multiple applications to equal the effect of the methomyl standard after three applications. Azinphosmethyl gave slightly better control of FAW larvae than did carbaryl or trichlorfon but was not as effective as methomyl. Reinfestation of whorl stage corn by FAW larvae occurred with all treatments and border types. The greatest reinfestation occurred after the first of three weekly applications. Studies suggested that border types, adjacent treatments, and cumulative effect of multiple applications are factors that critically influence the performance of insecticides applied to FAW larvae in small field plots.

Influence of Chemigation Parameters on Fall Armyworm Control in Field Corn

The application of pesticides in irrigation water (chemigation) is developing into a highly efficient and economical pest management strategy as the influence of application parameters are understood. In the current study, the effects of main-line water velocity, injection port direction, and sprinkler nozzle type were evaluated with two rates of chlorpyrifos to control fall armyworm larvae, Spodoptera frugiperda (J. E. Smith), in whorl-stage field corn grown under 0.6 ha center pivot irrigation systems. Chlorpyrifos injected into a main-line water velocity of 2.7 m/s generally gave as good or better fall armyworm control than when injected into a water velocity of 0.9 m/s regardless of sprinkler type. Upstream injection of chlorpyrifos formulated in non-emulsifiable oil resulted in better control of fall armyworm than did downstream injection. Chlorpyrifos applied with a 360@* spray sprinkler with coarse plates and nozzle orifice diam. between 3.6 and 9.5 mm at a main-line water velocity of 0.9 m/s gave the poorest fall armyworm control while an impact sprinkler gave the best control. The formulation droplet breakup in the main line and at the sprinkler were important factors in the distribution of insecticides to the target.

Effect of Various Chemigation Methodologies on Suppression of the Fall Armyworm (Lepidoptera: Noctuidae) in Corn

Studies were conducted in Tifton, Georgia during 1989 to compare the effectiveness of center-pivot irrigation sprinkler packages and various formulations of insecticides for the control of fall armyworm, Spodoptera frugiperda (J. E. Smith), infesting corn. Chemigation with Whirl-jet (E53) sprinklers provided better control of the pest than impact sprinklers or a Pass system. Chemigation with whirl-jet sprinklers controlled fall armyworm as well as a conventional hi-clearance sprayer. Asana XL 0.66 EC + oil chemigated with an irrigation simulator provided the most consistent control of fall armyworm larvae in whorl stage corn when compared with Asana XL + water, Lorsban 4E + oil, Lorsban 4E + water, Lorsban 6 (tech.) + oil, Larvin 3.2 + oil, and Larvin 3.2 + water. All tested materials resulted in significant reductions in fall armyworm damage to the whorls of corn.

Grain Sorghum Response to Fall Armyworm and Corn Earworm Infestation

In two plantings of grain sorghum, Sorghum bleolor (L.) Moench, we investigated the impact of whorl injury by natural infestations of fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), on subsequent panicle development and infestation. We also examined plant response to panicle infestation by corn earworm, Heliothis zea (Boddie) (Lepidoptera: Noctuidae). Treatments were applications of chlorpyrifos, methomyl, or Bacillus thuringiensis (Berliner) to the whorl, panicle, or both. Fall armyworm injury to the whorl caused light to moderate whorl injury in nontreated plots; injury was approximately 30% greater in the later planting, possibly reflecting differences in sorghum maturity. Fall armyworm damage delayed panicle development in the second planting by 2-4 d and may have prolonged anthesis. Fall armyworm injury did not measurably affect panicle oviposition by corn earworm. Whorl stage applications of chlorpyrifos apparently increased corn earworm survival on panicles, possibly because of toxicity to beneficials. Methomyl and chlorpyrifos were ovicidal for corn earworm, with up to 18-fold more noneclosed eggs recorded from treated than from nontreated panicles. Control of fall armyworm and corn earworm with chlorpyrifos increased yield in the second planting 106% relative to nontreated plots. Fall armyworm control with methomyl increased plant height 6.8% in the second planting relative to nontreated plots. Yield losses were significantly correlated with corn earworm density in the first planting and fall armyworm damage in the second.

Corn Earworm and Fall Armyworm Control in Peanuts in North Florida, 1989

Abstract The experiment was located in Jackson County, Fla., and planted 23 May. Plot size was 4 rows × 30 ft with a 36-inch row spacing. Experimental design was a randomized complete block with 4 replications. All insecticide treatments were applied on 1 Aug with a 2-row, CO2-powered backpack sprayer that was equipped with 3, D3 nozzles/row. These chemicals were applied at about 36 psi, with the amount of spray about 25 gal/acre. The density of CEW and FAW larvae in each plot was estimated 3, 8, 14, and 21 days later on 4, 9, 15, and 22 Aug, respectively, by taking 10 sweeps/plot with a 15-inch diam sweepnet.

Evaluation of Insecticides for Control of Corn Earworms and Fall Armyworms on Peanuts, 1990

Abstract This field test was conducted in conventionally planted and tilled peanut at the Wiregrass Substation in Headland, Ala. Eight treatments and a control were replicated 4 times in a randomized complete block design. Each plot was 4 rows wide (36 inch row spacing) and 50 ft long. Replicates were separated by a 15 ft alley. Treatments were applied in water on 26 Jul using a boom sprayer equipped with 3 TX3 nozzles/row operating at 40 psi and delivering 8.3 gal/acre. Insect populations were monitored by placing a standard 3-ft beat sheet between 2 randomly selected rows and by beating both rows. Samples were taken at 1 hr before treatment and at four and seven DAT.

Effect of Steinernema feltiae on Spodoptera frugiperda and Heliothis zea (Lepidoptera: Noctuidae) in Corn

The entomogenous nematode Steinemema feltiae Filipjev was evaluated for control of fall armyworm, Spodoptera frugiperda (J. E. Smith), in vegetative field corn ( Zea mays [L.J] and for control of fall armyworm and corn earworm, Heliothis zea (Boddie), in sweet corn ears. In 3 yr of field tests in vegetative field corn, spraying the nematode resulted in up to 33-43% infection of fall S. frugiperda larvae and occasionally significant ( P <0.05) reductions in numbers of S. frugiperda infesting the corn. There was no significant increase in total yield of corn, although the dry weight of kernels per ear was significantly ( P < 0.05) greater in treatment plots than in control plots. Nematode dosage had a significant effect on percentages of infection, but neither spray volume nor the addition of a surfactant affected insect control by the nematode. In one experiment in sweet corn, spraying the nematode onto corn ears resulted in up to 71% infection and up to 53% reduction of a mixed population of H. zea and S. frugiperda , mostly the former. Nematode treatments did not increase sweet corn yield by weight. However, spraying the nematode at a pressure of 0.70 kg/em2 resulted in a significantly ( P < 0.05) higher percentage of US #1 grade marketable ears than in control plots, whereas spraying at 1.76 kg/em2 did not, regardless of the nematode dose.

Fall Armyworm Control in Late-Planted Field Corn, 1989

Abstract ‘Pioneer 3147’ corn was planted on 25 Jun at the Highland Rim Experiment Station, Springfield. Eighteen treatments replicated 4 times were arranged in a randomized complete block design. Plots were 30 ft × 6 rows with 10 ft alleys between plots and blocks. Rows were spaced 40 inches apart with 37 plants/30 row ft. The 4 inner rows were treated and the 2 middle rows were evaluated for whorl damage and harvested for yield determinations. Liquid formulations were applied using 2.5 gal compressed CO2 sprayers at 30 psi and 30 gal/acre. Granular insecticides were applied with shaker jars. Insecticides were applied on 18 Jul when 90% of the plants were infested with an average of 1.33 larvae/plant. Whorls newly damaged by the fall armyworm (FAW) were counted on 25 Jul, 1 and 8 Aug. Ensilage yields were determined on 30 Oct at 60% moisture. Soil type was Dixon silt loam, 2-5% slope, pH 6.0.

Chemigation to Control Fall Armyworm in Field Corn, 1989

Abstract Field corn was planted 23 Aug on USDA facilities, Tifton, GA. Plots were 6 rows wide (36-inch spacing) and 40 ft long with 3 ft alleys separating plots on the same row. Plots were arranged in a randomized complete block design with 4 replications. Plants were in the whorl stage at the time of applications. Chemigation treatments were applied with a chemigation simulator calibrated to deliver 2172 gal of water/acre through 4 E53 whirljet nozzles at 10 psi. Desired insecticide concentrations were mixed in either vegetable oil or water at a rate of 2.1 qt of material/acre. Thirty plants/plot were randomly selected from the 2 center rows, and the number of freshly damaged plants and larval species composition noted. Counts were performed prior to initiation of the test and 48 h after each treatment.

Fall Armyworm (Lepidoptera: Noctuidae) Infestations in No-Tillage Cropping Systems

Field experiments comparing no-tillage and plow-tillage practices demonstrated that infestations by the fall armyworm, Spodoptera frugiperda (J. E. Smith), ultimately become similar in either cropping system. However, in certain no-tillage situations where high mulch concentrations were present on the soil surface, oviposition and damage were reduced. Significantly fewer egg masses and damage were sampled on corn, Zea mays L., (3-leaf stage) while seedlings remained within no-tillage mulch. Oviposition quickly became similar to that observed in plow-tillage systems when the plants grew above the mulch canopy of no-tillage. The number of egg masses on corn older than 4 leaves was similar in either cropping system, and leaf injury at plant silking was the same. In a comparison of corn, sorghum (Sorghum bicolor [L.] Moench.), and soybeans (Glycine max L.), the latter crop had no damage in either tillage system while corn and sorghum were heavily infested. Efficacy of chlorpyrifos (0.56 kg [AI]/ha) for controlling fall armyworm leaf damage was similar in corn and sorghum in either cropping system.

Control of Fall Armyworm in Whorl Stage Sweet Corn, 1987

Abstract A small-plot field experiment was conducted to screen insecticides for control of leaf-feeding damage to sweet corn seedlings by the fall armyworm. Sweet corn was planted 11 Aug in an Appling loamy coarse sand. The experiment was a randomized complete block design with 2-row plots, 20 ft long and 38 inches wide, with 5-ft alleys, replicated 5 times. Full-cone sprays were applied at 30 psi, directed over the whorl in a final volume of 25 gal/acre. Sprays were initiated when plants were in the 4th leaf stage at a time when 50% showed leaf feeding symptoms of 1st instar larvae. Plants were sprayed on 2, 9, and 16 Sep. On 9 and 28 Sep, all plants in each plot were rated for fall armyworm damage using the following 0-7 damage index: 0, no damage; 1, slight leaf feeding, but no indication of bud damage; 2, moderate leaf feeding, but no bud damage; 3, heavy leaf feeding and no bud damage; 4, slight to moderate feeding and slight bud damage; 5, moderate to heavy leaf feeding damage and moderate to heavy bud damage; 6, heavy leaf feeding and severe bud damage; and 7, plant virtually destroyed.

Control of Fall Armyworm by Aerial Application of Insecticides, 1987

Abstract One commercial 16-acre field, located near Potter, N.Y., was used for this test. Within the field 5 plots, each 40 ft wide by 900 ft long, were delineated. Within the center of each plot we marked a section of 100 plants in the early whorl stage. Into the whorls of each of the 500 plants, about 15 newly hatched FAW larvae (from a Du Pont-maintained Lannatesusceptible culture) were deposited on 15 Jul using a “bazooka” dry-grit Davis innoculator. On 21 Jul, each section was sprayed with 1 of 4 insecticides. A Schweizer Ag-Truck plane was used to deliver all treatments. Liquid insecticides were applied a 3 gal/acre, 35-40 psi with D8-45 nozzels and 115-120 mph. On 27 Jul 50 plants from each treatment were evaluated for the number of live FAW larvae. After this evaluation, 1 additional spray of EPN and 2 additional sprays of Penncap-M (all at 0.5 lb [AI]/acre) were sprayed on 4, 11, and 18 Aug, respectively. On 25 Aug the remaining 50 ears in each treatment were evaluated for ear injury.

Whorl Applications to Control Fall Armyworm in Corn, 1987

Abstract 'Silver Queen' sweet corn was planted 13 Jul in a Sassafras sandy loam field. Plots were 4 rows wide on 30-inch centers and 25 ft long. Treatments were replicated 4 times in a randomized complete block design. Granular whorl treatments were applied with a hand shaker in a 7-inch band over the whorl on 18 and 24 Aug. No other treatments were applied. Twenty whorls were rated for fall armyworm damage on 26 Aug as follows: 0, no damage; 1, slight damage, up to 10% whorl feeding; 2, moderate damage, 10-25% whorl feeding; 3, heavy damage, 25-50% feeding damage; 4, severe damage, 50-75% whorl feeding, tassel damaged; and 5, whorl destroyed. Twenty whorls were removed from the plants, unrolled, and all live armyworm larvae were counted. On 6 Oct, 20 ears were harvested and weighed. On 16 Oct, 20 plants in each plot were measured to determine plant height from the soil surface to the tip of the tassel. On 19 Nov, 10 stalks from the center 2 rows of each plot were split from 3 nodes above the ear to 3 nodes below the ear and each 2.5 cm of ECB damage was recorded as one cavity.

Control of Fall Armyworm (FAW) by Aerial Applications of Liquid Insecticides, 1986

Abstract One commercial field, located near Avon, NY, was used for this test. The field was divided into 4 sections and each section contained a subsection of 100 plants in the silking stage. On the silks of each of the 400 plants, 15 newly hatched FAW larvae were deposited on 3 Aug. On 5 Aug, each section was sprayed with 1 of 3 insecticides. Additional sprays of each insecticide were applied on 13 and 19 Aug. A spray of Penncap was substituted for the 19 Aug EPN spray because of PHI. A Grumman Air Cat, delivering 3 gal/acre, was used to apply the sprays. At harvest (29 Aug), 50 ears from each treatment were evaluated for damage.

Control of Fall Armyworm in Field Corn, 1985

Abstract 'Pool 24' corn was planted on 5 Jul at the Poza Rica Experiment Station, Puebla, Mexico. Twenty four treatments were replicated 4 times in a randomized complete block design. Plot size was 6 rows (0.75 m apart) × 5.0 m. Corn was thinned to 40,404 plants per hectare. All rows were infested, but only the four central ones were treated and evaluated. An avg of 26.4 larvae/plant were initially applied on 18 Jul when the crop was at the 3 expanded leaf stage. On 1 Aug the crop was reinfested at the 7-8 expanded leaf stage with an avg of 21 larvae/plant. The insecticides were applied on 24 Jul with corn at the 5.5 leaves stage. Liquid formulations were applied with a bicycle compressed air sprayer, using 8004 nozzles, 2.8 kg/cm2 and delivering 483 liters/ha. Granular formulations were applied with hand applicators, delivering 0.2 cc/stroke. Evaluations consisted of: a) Number of total and undamaged plants, at three intervals: one week after initial infestation, one week after treatment application ;md one week after reinfestation; b) Plant and ear height, on 12 Sep; c) Number of harvested plants and ears, and grain yield (15% moisture) on 24 Oct.