Celama Sorghiella Research Articles

Evaluation of Selected Insecticides for Control of Caterpillar Pests in Grain Sorghum, 2015: Table 1

Selected insecticide treatments were evaluated for control of corn earworm, sorghum webworm, and fall armyworm in grain sorghum at the Research and Education Center at Milan (Milan, TN). Grain sorghum was planted on 17 Jun. The test was arranged in a RCB design with four replicates. Individual plots were 12.5 × 30 ft. Treatments were applied with a high clearance sprayer calibrated to deliver 9.4 GPA at 40 PSI with 8001 flat fan nozzles. Foliar applications were made on 19 Aug, prior to infestation by caterpillar pests. The …

Efficacy of Insecticides for Control of Insect Pests of Pearl Millet for Grain Production

Pearl millet [Pennisetum glaucum (L.) R. Br.] is an alternative drought-tolerant grain crop for dryland summer production. Few insecticides are registered for use and insect management has not been extensively studied in pearl millet for grain production. Eleven trails were conducted during 2002-2004 in central and southern Georgia to understand the relative importance of insect pests and to evaluate the efficacy of currently registered insecticides against key pests. The main defoliator species were the fall armyworm [Spodoptera frugiperda (J.E. Smith)] and striped grassworm (Mocis latipes Guenée). Main insects feeding on grain heads were the corn earworm (Helicoverpa zea Boddie), sorghum webworm, (Nola sorghiella Riley), and stink bugs — brown stink bug (Euschistus spp.) and southern green stink bug [Nezara viridula (L.)]. All insects were effectively controlled by cypermethrin at 0.025 lb a.i./acre. The 0.015-lb a.i. rate was effective against sorghum webworm, striped grassworm, and stink bugs, but efficacy against the corn earworm was variable. Spinosad was effective against corn earworm, striped grassworm, and sorghum webworm but not against stink bugs. Azadirachtin was not effective against any insect tested. Grain yield was not significantly affected by treatments in any trial indicating that pearl millet is tolerant of insect injury. Further work will be needed to define economic thresholds for key insect pests of pearl millet for grain production. Accepted for publication 24 August 2006. Published 19 February 2007.

Control of Panicle Caterpillars on Sorghum, 1997

Abstract Insecticides were evaluated for control of panicle caterpillars at the Texas Agricultural Experiment Station Research Farm near College Station, TX. Panicle caterpillars included corn earworm, fall armyworm, and sorghum web-worm. Seed of hybrid sorghum (ATx399 X RTx430) was planted 16 Jun on rows spaced 30 inches apart. Insecticide treatments were compared in plots, 8 rows X 40 ft long, arranged in a RCB design with 4 replications. Insecticides were applied to the middle 2 rows of plots when sorghum was in the dough stage. Insecticides were applied on 9 Sep between 0930 and 1100 h CDT by using a hand-held backpack sprayer with 4, TX-3 hollow cone nozzles at 35 psi. producing a finished spray volume of 4.9 gpa. Caterpillar abundance was assessed by using the “beat bucket” technique to sample 10 panicles per plot. A pre-treatment count of headworms and webworms was made just prior to insecticide application. Post-treatment counts were made on 10(1 DAT) and 12 Sep (3 DAT). Data were statistically analyzed by using ANOVA and LSD. Percent control was calculated by using the Henderson and Tilton (1955) sampling formula.

Evaluation of Selected Sampling Methods for Panicle-Infesting Insect Pests of Sorghum

Field studies were conducted to evaluate methods for estimating field abundance of corn earworm, Helicoverpa zea (Boddie), sorghum webworm, Celama sorghiella (Riley), rice stink bug, Oebalus pugnax (F.), and sorghum midge, Contarinia sorghicola (Coquillett), infesting grain sorghum. A “beat-bucket” method for separating panicleinfesting lepidopteran and hemipteran pests from the panicle captured 100% of rice stink bug adults, 95-100% of rice stink bug nymphs, 78-98% of corn earworm larvae, and 77% of sorghum webworm larvae. In situ visual estimates by experienced samplers of sorghum midge densities on panicles were highly correlated with estimates provided by wholepanicle samples ( r 2 = 0.92) and =89% of the insects were detected. Both the in situ and whole-panicle methods appeared suitable for field scouting. A sticky trap for sorghum midge was described and evaluated. Daily average sticky trap catches were significantly correlated with the average number of sorghum midge per panicle as estimated by wholepanicle samples ( r 2 = 0.85).

Evaluation of Bacillus Thuringiensis Products for Control of Sorghum Webworm on Grain Sorghum, 1989

Abstract Commercial B. thuringiensis products were evaluated against sorghum webworm in Garland Co., AR. Treatments against first to third instars were applied on 11 Sep with a backpack sprayer equipped with a 1 row boom using a single TX-10 nozzle operating at 30 psi. The volume of spray was 96 liters/ha. A randomized complete block experiment was used with 4 replicates. Plots were 4 rows with 1.08 m spacing × 30.8 m in length. Plots were separated by a 2-row buffer. Treatments were evaluated at 4 and 7 DAT. Ten heads per plot were randomly chosen from the 2 inside rows and shaken into a 9.5 liter pail. Larvae collected were counted and numbers recorded. The main minimum and maximum temperatures during the test were 16.1 and 27.8°C, respectively. No significant rainfall occurred during the period. Data were analyzed using ANOVA and LSD procedures.

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

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.

Parasitism of Heliothis zea (Lepidoptera: Noctuidae) Eggs and Larvae and Celama sorghiella (Lepidoptera: Noctuidae) Eggs on Grain Sorghum Panicles

Grain sorghum panicles were collected and examined for Heliothis zea (Boddie) eggs and larvae and Celama sorghiella (Riley) eggs during 1986–1988 in seven sorghum fields along the Red River in southwestern Arkansas, northeastern Texas, and southeastern Oklahoma. Trichogramma exiguum (Pinto and Planter) and T. pretiosum Riley were the predominant parasites attacking H. zea and C. sorghiella eggs. Trichogramma spp. appeared to be an important mortality factor of H. zea and C. sorghiella eggs on grain sorghum panicles, particularly if H. zea or C. sorghiella eggs were available through the season for Trichogramma spp. to build up on. Seven species of parasites were reared from H. zea larvae; one eulophid, three tachinids, and three braconids. The incidence of larval parasitism was low, less than 2%, for the three-year study and appeared to have a minimal effect on larval numbers.

Within-Field and Within-Panicle Distribution of Heliothis zea (Lepidoptera: Noctuidae) and Celama sorghiella (Lepidoptera: Noctuidae) Eggs in Grain Sorghum

The within-field and within-panicle distributions of Heliothts zea (Boddie) and Celama sorghiella (Riley) eggs were studied in Arkansas grain sorghum during 1985 and 1986. The distribution of eggs parasitized by Trichogramma spp. was also evaluated. None of the three insect species showed a consistent preference for any portion of a grain sorghum panicle based on either location (upper, middle, or lower third) or flowering stage (⅓, ⅔, or full bloom). H. zea exhibited a clumped within-field spatial pattern for total and parasitized eggs as based on Taylor's indices of aggregation ( a = 1.24, b = 1.31, and a = 1.85, b = 1.18, respectively). Total and parasitized C. sorghiella eggs were decidedly more aggregated than those of H. zea with Taylor's indices of a = 2.56, b = 1.46, and a = 3.28, b = 1.34, respectively. Required sample sizes needed to estimate population densities of both species are provided.

Insecticide Control of Pests on Sorghum in Arkansas, 1987

Abstract Populations of sorghum webworm and corn earworm were observer 20 Aug feeding on sorghum (pre-milk), planted 20 Jun in Little River County. Insecticide treatments were applied to plots of 50 ft × 1 row. An untreatec buffer row was left between plots. Treatments were arranged in a completely randomized block design with 4 replicates. Insecticides were applied using L backpack sprayer delivering 13.6 gal/acre at 30 psi through a single Teejet TX10 nozzle. Sprays were applied approximately 10-12 inches above the sorghun panicles on 20 Aug between 10 A.M. and 12 A.M. Ten panicles/plot were randomly tagged pretreatment. The effectiveness of the treatments was evaluate! on 21 Aug (24 h postapplication) by selecting 5 of the tagged panicles from each treatment in each replication. The panicles were clipped and twirled in white plastic bucket, and the number of live sorghum webworms and corn earworms was counted. The other 5 panicles were hand harvested 25 Sep fron each row. The panicles were threshed and the grain was weighed. Data were analyzed by conventional analysis of variance and multiple-comparison procedures

Insecticide Control of Sorghum Head Worms in Georgia, 1986

Abstract Two sorghum tests were planted, one on 23 Jun and one 10 Jul, at the University of Georgia Experiment Station, Oconee Co., in Appling coarse sandy loam soil. The experiment was a randomized complete block design with 2 row plots × 20 ft long × 38 inch row width × 3 ft alleys with 5 replicates. Plants were treated with a full cone spray using an air pressure sprayer at 30 psi in a final volume of 25 gal/acre directed on the heads when 15% of die panicles were in bloom and again 5 days later. Ten consecutive heads (1st test) or 8 heads (2nd test) in a row were shaken vigorously into a plastic bucket 10 days after the last spraying and the contents were placed in a labeled plastic bag. The bags were returned to the laboratory, frozen, and the contents were examined for the presence of corn earworm larvae, fall armyworm larvae, and sorghum webworm larvae.

Insecticidal Control of Sorghum Webworm in Louisiana, 1985

Abstract Six insecticides were evaluated for control of the sorghum webworm at the LSU, Idlewild Experiment Station, East Feliciana Parish, LA. Grain sorghum was planted in a conventional manner on 25 May. Insecticide treatments were 50 ft × 1 row with an untreated row between treatments. A completely randomized block design was used with 4 replications, 5 ft alleys between replicates and 38 inch row spacing. Insecticides were applied using a backpack CO2 pressurized sprayer delivering 16 gal/acre at 55 psi through a single Teejet 8002 E nozzle. Sprays were applied approximately 6 inches above the sorghum heads on 6 Aug. The effectiveness of the treatments was evaluated on 9 Aug by counting the number of live webworms on 5 randomly selected sorghum heads from each treatment in each replication. Webworms were counted by clipping and bagging the heads, shaking them over a white porcelain pan, and counting the number of live webworm larvae.

Control of Pests on Sorghum in Mississippi, 1983

Abstract Populations of sorghum webworm, corn earworm and fall armyworm larvae (4th-5th instars) were observed on 5 Sep feeding on sorghum cv. Dekalb 42 Y (dough stage), planted on 11 Jul in Oktibbeha County, MS. Populations exceeded 47, 11 and 46 per 10 heads selected randomly from the field for sorghum webworm, corn earworm and fall armyworm, respectively. Plots were 1 row wide and 20 ft in length arranged in a randomized complete block with 3 replicates. Insecticides were applied in 10 gal of water per acre with a hand-held compressed air sprayer equipped with a solid-cone nozzle using 30 psi. The time of application was between 3 and 4 p.m. The temperature was ca 89°F. On 9 Sep (day 4 post application) treatment plots were sampled by removing 10 heads randomly from each treatment plot. Sorghum heads for each treatment were placed in paper bags and returned to the lab for examination.

Sorghum Webworm Control and Flower Bug Mortality on Sorghum in Mississippi, 1983

Abstract Populations of sorghum webworm larvae were observed on 15 Sep feeding on sorghum cv. Dekalb 42 Y (hard-dough stage), planted on 11 Jul in Oktibbeha County, MS. Populations exceeded 102 webworms per 10 heads selected randomly from the field. Plots were 1 row wide and 44 ft in length arranged in a randomized complete block with 3 replicates.

Sorghum Webworm Control, 1983

Abstract Three insecticides were evaluated for control of the sorghum webworm at the LSU, Idlewild Exp. St., East Feliciana Parish, La. Funks 522 DR grain sorghum was planted in a conventional manner on 11 July. Treatments were 50 ft by one row with an untreated row between treatments. A completely randomized block design was used with four replications, 5-ft alleys between replicates and 38 in. row spacing. Insecticides were applied using a back-pack, CO2 pressurized sprayer delivering 16 gal/acre at 55 lb/in2 through a single Teejet 8002 E nozzle. Sprays were applied from approximately 6 in. above the sorghum heads on 14 Sep. A pretreatment count of 100 randomly-selected heads in the test area yielded a mean of 17.9 webworms per head. The effectiveness of the insecticides was evaluated on 16 Sep. by counting the number of webworms shaken from 20 randomly selected heads from each treatment in each replication. The heads were brought into the laboratory, shaken over a white porcelin pan and inspected for live webworms that failed to dislodge.

Control of Lepidopteran Larvae Attacking Sorghum Grain Heads, 1982

Abstract ‘Funk’s G522DR’ was planted on Jun 23 by conventional tillage methods in a Cecil loamy clay soil type in Pike Co, GA. Plots were 6.1 m x 2 rows (91-cm row spacing) and were separated by 2 untreated rows and 1-m alleys. Insecticides were applied on Aug 31 with a CO2 backpack sprayer calibrated to deliver 370 1/ha at 2.0-2.2 kg/cm2. Numbers of corn earworm (CEW) and sorghum webworm (SWW) larvae were determined before treatment and 1 and 2 days after treatment by shaking 10 randomly selected grain heads/plot into a bucket. Treatments were replicated 4 times in a RCB design.

Sorghum Webworm Control, 1980

Abstract Three tests evaluated various materials in suppressing sorghum webworm populations on grain sorghum heads. All tests were planted with Funk’s G522DR on July 2 by minimal tillage methods following wheat. Plots were 6.1 m x 3 rows and were separated by 1 untreated row or 1 m alley. Treatments were replicated 4 times in a randomized complete block design. Applications were made with compressed-air sprayers calibrated to deliver 50 gal per acre at 30 psi. Spray was directed to opposite sides of heads to insure thorough coverage. One application on Sept 18 was used in Test 1. Low pest population levels did not merit a second application. Two applications were made on Oct 3 and 8 in Tests 2 and 3. Larval populations were estimated on each sampling date by shag-bagging 10 randomly-selected heads from each plot.

Epizootics of Entomophthora aulicae in lepidopterous pests of sorghum

Entomophthora aulicae caused 48–100% mortality in Heliothis zea larvae collected from sorghum August 24–September 6, 1978, in Tift County, Georgia. The same fungus also caused 74 and 95% mortality in Celama sorghiella larvae and 19 and 40% mortality in Spodoptera frugiperda larvae collected from sorghum August 30 and September 6 in the same area. Only 2 of 94 H. virescens larvae collected from a nearby patch of pigeon peas were killed by the fungus. This is the first report of epizootics caused by E. aulicae in pests of field crops in the southeastern United States.

Management Tactics for the Sorghum Webworm in Sorghum12

Damaging infestation levels of Celama sorghiella (Riley) were avoided by early planting of sorghum. Sorghum planted by Apr. 1 and flowering before June 20 in the Coastal Bend of Texas, and sorghum planted by Apr. 10 and flowering before July 1 in south-central Texas escaped damaging infestations of sorghum webworm. Sorghum panicle type (open vs. compact) ratings and sorghum webworm infestation levels were positively correlated (r2 = 0.8). Data showed that as sorghum panicles increase in compactness, sorghum webworm densities also increase. There was no positive correlation between sorghum webworm infestation levels and seed endosperm type or panicle size. Also, no association was apparent between egg deposition and panicle type within 6 days of panicle exertion; webworm mortality was high by the 10th day after 50% flower. Germ plasm resistant to sorghum web worm was difficult to identify, but differences in infestation levels indicated possible resistant sources.

Effect of Sorghum Webworm on Yield of Grain Sorghum in Oklahoma12

The sorghum webworm, Celama sorghiella (Riley), is a potential threat to sorghum production in Oklahoma, and in years of higher-than-normal precipitation, late plantings may sustain heavy losses. Populations of the pest were regulated experimentally by treatment with doses of mevinphos, and the amount of grain consumed at the different population levels was estimated. Each larva consumed an average of 0.79 g of grain. At an assumed market price of $1.90 per hundredweight and a total treatment cost of $2.50 per acre, a saving of 132 lb of sorghum per acre would just offset the cost of treatment. With an average distance between heads of 8 inches and a row spacing of 40 inches, a population level of approximately 5 larvae per head should justify treatment.

Effectiveness of Insecticides Against the Sorghum Webworm Sorghum Heads1

Twelve materials were tested against infestations of the Sorghum webworm ( Celama sorghiella (Riley)) in sorghum heads. Sevin® (1-naphthyl N -methylcarbamate-), Guthion® ( O,O -dimethyl S -(4-oxo-1,2,3-benzotriazin-3-(4 H )-ylmethyl) phosphorodithioate). Phosdrin® (a mixture of the alpha isomer of 2-carbomethoxy-1-methylvinyl dimethyl phosphate (not less than 60%) and related compounds (not more than 40%)), naled (Dibrom), phosphamidon, and parathion gave the most effective control. Di-Syston® ( O,O -diethyl S -[2-(ethylthio) ethyl] phosphorodithioate) as a granular formulation apparently had no effect on sorghum webworm larvae infesting sorghum heads.