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1.
J Econ Entomol ; 114(2): 739-746, 2021 04 13.
Article in English | MEDLINE | ID: mdl-33576417

ABSTRACT

Tarnished plant bug, Lygus lineolaris Palisot de Beauvois (Hemiptera: Miridae), has become a primary pest of cotton in the Midsouthern United States. Insect growth regulators such as novaluron are an important part of L. lineolaris management. While novaluron is lethal to nymphs, it does not kill adults, so it has been used when nymphs are the primary stage present. However, cotton yield protection was observed from an application of novaluron when adults were the predominant stage present. To explain this, a series of studies were conducted to examine sublethal impacts of novaluron to L. lineolaris adults. Novaluron ingestion by adults reduced hatch rate and sometimes reduced oviposition rate. Ingestion by either males or females reduced hatch rates, but the reduction was greater from female exposure. Contact exposure of adults with novaluron residues within 1 d of application reduced hatch rate by about 50%, but the impact on oviposition was inconsistent. A field study showed reduced hatch rate from contact exposure to mixed-age natural populations, but the overall net reproductive rate was not reduced. Surface exposure of eggs to novaluron did not reduce hatch rate. Overall, exposure of tarnished plant bug adults to novaluron, regardless of adult age or exposure route, reduced egg viability. However, the impact on oviposition rate and net reproductive rate varied with adult age and exposure route. This understanding of sublethal impacts of novaluron, in addition to lethal impacts on nymphs, should be considered when choosing application times to maximize effects on L. lineolaris populations.


Subject(s)
Hemiptera , Heteroptera , Animals , Female , Male , Nymph , Oviposition , Phenylurea Compounds/pharmacology
2.
J Econ Entomol ; 111(1): 10-15, 2018 02 09.
Article in English | MEDLINE | ID: mdl-29281077

ABSTRACT

Neonicotinoid insecticides are currently one of two classes of chemicals available as a seed treatment for growers to manage early season insect pests of cotton, Gossypium hirsutum L. (Malvales: Malvaceae), and they are used on nearly 100% of cotton hectares in the midsouthern states. An analysis was performed on 100 seed-treatment trials from Arkansas, Louisiana, Mississippi, and Tennessee to determine the value of neonicotinoid seed treatments in cotton production systems. The analysis compared seed treated with neonicotinoid insecticides seed treatments plus a fungicide with seed only treated with fungicide. When analyzed by state, cotton yields were significantly greater when neonicotinoid seed treatments were used compared with fungicide-only treatments. Cotton treated with neonicotinoid seed treatments yielded 123, 142, 95, and 104 kg ha-1, higher than fungicide only treatments for Arkansas, Louisiana, Mississippi, and Tennessee, respectively. Across all states, neonicotinoid seed treatments provided an additional 115 kg lint ha-1 comparedwith fungicide only treated seed. Average net returns from cotton with a neonicotinoid seed treatment were $1,801 per ha-1 compared with $1,660 per ha-1 for cottonseed treated with fungicide only. Economic returns for cotton with neonicotinoid seed treatments were significantly greater than cottonseed treated with fungicide only in 8 out of 15 yr representing every state. These data show that neonicotinoid seed treatments provide significant yield and economic benefits in Mid-South cotton compared with fungicide only treated seed.


Subject(s)
Fungicides, Industrial , Insect Control/methods , Insecticides , Neonicotinoids , Arkansas , Crop Protection/economics , Crop Protection/methods , Gossypium/growth & development , Insect Control/economics , Louisiana , Mississippi , Seeds/physiology , Tennessee
3.
J Econ Entomol ; 111(1): 187-192, 2018 02 09.
Article in English | MEDLINE | ID: mdl-29177425

ABSTRACT

Neonicotinoid seed treatments are one of several effective control options used in corn, Zea mays L., production in the Mid-South for early season insect pests. An analysis was performed on 91 insecticide seed treatment trials from Arkansas, Louisiana, Mississippi, and Tennessee to determine the value of neonicotinoids in corn production systems. The analysis compared neonicotinoid insecticide treated seed plus a fungicide to seed only with the same fungicide. When analyzed by state, corn yields were significantly higher when neonicotinoid seed treatments were used compared to fungicide only treated seed in Louisiana and Mississippi. Corn seed treated with neonicotinoid seed treatments yielded 111, 1,093, 416, and 140 kg/ha, higher than fungicide only treatments for Arkansas, Louisiana, Mississippi, and Tennessee, respectively. Across all states, neonicotinoid seed treatments resulted in a 700 kg/ha advantage compared to fungicide only treated corn seed. Net returns for corn treated with neonicotinoid seed treatment were $1,446/ha compared with $1,390/ha for fungicide only treated corn seed across the Mid-South. Economic returns for neonicotinoid seed treated corn were significantly greater than fungicide-only-treated corn seed in 8 out of 14 yr. When analyzed by state, economic returns for neonicotinoid seed treatments were significantly greater than fungicide-only-treated seed in Louisiana. In some areas, dependent on year, neonicotinoid seed treatments provide significant yield and economic benefits in Mid-South corn.


Subject(s)
Crop Protection/methods , Fungicides, Industrial/administration & dosage , Insect Control/economics , Insecticides/administration & dosage , Neonicotinoids/administration & dosage , Zea mays , Crop Protection/economics , Southeastern United States , Tennessee , Zea mays/growth & development
4.
J Econ Entomol ; 109(4): 1859-71, 2016 08.
Article in English | MEDLINE | ID: mdl-27329627

ABSTRACT

Blended refuge for transgenic plants expressing Bacillus thuringiensis (Bt) toxins has been approved in the northern United States as a resistance management strategy alternative to a structured refuge. A three-year study (2012-2014) was conducted with 54 trials across nine states in the southern United States to evaluate plant injury from lepidopteran pests of corn and yield in a corn hybrid expressing Cry1F × Cry1Ab × Vip3Aa20 (Pioneer Brand Optimum Leptra) planted as a pure stand and in refuge blends of 5, 10, and 20% in both early and late plantings. Injury by corn earworm, Helicoverpa zea Boddie (Lepidoptera: Noctuidae), and fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), was generally proportional to the percentage of non-Bt corn within each refuge blend. Across locations, ear injury in plots with 100% Cry1F × Cry1Ab × Vip3Aa20 (Optimum Leptra) corn ranged from no injury to a maximum of 0.42 cm(2) per ear in Mississippi in 2013. Leaf injury ratings in 100% non-Bt plots in early and late planted trials in 2014 were 86- and 70-fold greater than in 100% Cry1F × Cry1Ab × Vip3Aa20 (Optimum Leptra) plots. Plants in plots with blended refuges had significantly greater leaf injury in 2012 (5, 10, and 20% refuge blends), in the early-planted corn in 2013 (10 and 20% only), and in both early- and late-planted corn in 2014 (20% only) as compared with leaf injury in a pure stand of Cry1F × Cry1Ab × Vip3Aa20 (Optimum Leptra) seen during these years. Corn ears in plots with blended refuges also had significantly greater area of kernels injured in 2012 (5, 10, and 20%), in early- and late-planted corn in 2013 (5, 10, and 20%), and in early (10 and 20% only)- and late-planted corn (5, 10, and 20%) in 2014 as compared with ear injury in a pure stand of Cry1F × Cry1Ab × Vip3Aa20 (Optimum Leptra) seen during these years. Infestations of southwestern corn borer, Diatraea grandiosella Dyar (Lepidoptera: Crambidae), were also significantly reduced by Cry1F × Cry1Ab × Vip3Aa20 (Optimum Leptra). Despite these differences in injury, yield averaged across locations varied among refuge blends only in the late-planted trials in 2013, with greater yields in the 0% refuge blend than in the 20% blend; however, when examining yield separately by location, only two of nine locations had higher yields in the 100% Bt plots than in any of the blended refuge plots. As a complement to studying the contribution of blended refuge to delaying resistance, quantifying injury and yield in a range of refuge blends is a necessary step to provide management information on the range of lepidopteran pests that occur in the southern United States.


Subject(s)
Bacillus thuringiensis/chemistry , Bacterial Proteins/pharmacology , Bacterial Toxins/pharmacology , Moths/physiology , Zea mays/physiology , Animals , Bacillus thuringiensis/genetics , Insecticide Resistance , Pest Control, Biological , United States , Zea mays/genetics , Zea mays/growth & development
5.
J Econ Entomol ; 109(3): 1161-1166, 2016 Apr 10.
Article in English | MEDLINE | ID: mdl-27063843

ABSTRACT

Field experiments were conducted in Starkville and Stoneville, MS; Marianna, AR; Winnsboro, LA; and Jackson, TN, during 2012 and 2014 to evaluate the relationship of corn earworm, Helicoverpa zea (Boddie), larval density and yield and the relationship between the percentage of damaged pods and yield in Mid-South soybean systems. Corn earworm moths were infested into field cages at R2 for 5-11 d to achieve a range of larval densities within each plot. Larval density was estimated at 14 d after infestation. Total pods and damaged pods were determined at 19 days after infestation to obtain the percentage of damaged pods. Plots were harvested at the end of each growing season and yield recorded. Data were subjected to regression analysis, and the relationship between larval density and yield and the relationship between the percentage of damaged pods and yield both can be described by a linear relationship. Each increase of one larvae per row-m resulted in a yield loss of 45.4 kg/ha. Similarly, each increase of 1% damaged pods resulted in a yield loss of 29.4 kg/ha. From these data, economic injury levels were developed for a range of crop values and control costs. These data suggest that current corn earworm threshold use in the Mid-South should be reduced.

6.
J Econ Entomol ; 109(3): 1156-1160, 2016 Apr 18.
Article in English | MEDLINE | ID: mdl-27091814

ABSTRACT

Early-season insect management is complex in the Mid-South region of the United States. A complex of multiple pest species generally occurs simultaneously at subthreshold levels in most fields. Neonicotinoids are the only insecticide seed treatment widely used in soybean, Glycine max L., production. An analysis was performed on 170 trials conducted in Arkansas, Louisiana, Mississippi, and Tennessee from 2005 to 2014 to determine the impact of neonicotinoid seed treatments in soybean. The analysis compared soybean seed treated with a neonicotinoid insecticide and a fungicide with soybean seed only treated with the same fungicide. When analyzed by state, soybean yields were significantly greater in all states when neonicotinoid seed treatments were used compared with fungicide-only treatments. Soybean treated with neonicotinoid treatments yielded 112.0 kg ha -1 , 203.0 kg ha -1 , 165.0 kg ha -1 , and 70.0 kg ha -1 , higher than fungicide-only treatments for Arkansas, Louisiana, Mississippi, and Tennessee, respectively. Across all states, neonicotinoid seed treatments yielded 132.0 kg ha -1 more than with fungicide-only treated seed. Net returns from neonicotinoid seed treatment usage were US$1,203 per ha -1 compared with US$1,172 per ha -1 for fungicide-only treated seed across the Mid-South. However, economic returns for neonicotinoid seed treatments were significantly greater than fungicide-only treated seed in 4 out of the 10 yr. When analyzed by state economic returns the neonicotinoid seed treatments were significantly greater than fungicide-only treated seed in Louisiana and Mississippi. These data show that in some areas and years, neonicotinoid seed treatments provide significant economic benefits in Mid-South soybean.

7.
J Econ Entomol ; 108(4): 1795-803, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26470321

ABSTRACT

Cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a common pest of cotton throughout much of the world. In the United States, insecticide applications targeting cotton aphid in cotton are common in the Mid-South, Texas, and California. Cotton aphid population dynamics data were collected from eight insecticide efficacy trials conducted in Lubbock, TX, over a 4-yr period. Among the field populations in the nontreated plots, the instantaneous rate of population growth averaged 0.56 ± 0.608, and the mean population doubling time was 3.97 ± 2.16 d. For calculating economic injury levels (EIL) and thresholds, control costs were set at US$30.50/ha, market prices were evaluated at US$0.88, US$1.33, US$1.77, and US$2.21 kg-lint, and cotton yield potentials were evaluated at 672, 896, and 1,120 kg-lint/ha. The EIL we calculated ranged from 66 to 272 aphids per leaf, and averaged 137 aphids per leaf. Economic thresholds (ET) were calculated based on lead times of 1, 3, 5, and 7 d before EIL occurs. The mean ET across control cost, market price, and yield potential were 110 ± 48, 70 ± 31, 45 ± 19, and 29 ± 13 aphids per leaf at lead times of 1, 3, 5, and 7 d, respectively. Most curative pest management tactics in cotton are implemented within 3 d of determining need, and the ET at 3 d that we calculated (70 ± 31 aphids per leaf) overlaps the current recommended action threshold in Texas and California of 50 aphids per leaf.


Subject(s)
Aphids/physiology , Crops, Agricultural/growth & development , Gossypium/growth & development , Insect Control/economics , Animals , Crops, Agricultural/economics , Population Dynamics , Texas
8.
J Econ Entomol ; 96(3): 805-10, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12852620

ABSTRACT

We tested effects of kaolin particle film on oviposition, larval mining, and infestation of cotton by pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), in the laboratory, greenhouse, and field. In laboratory choice tests, females laid seven times more eggs on untreated bolls than on bolls treated with kaolin. When neonates were put on bolls in the laboratory, each boll with a treated and untreated half, larvae and mines were found 24 h later on the untreated half but not on the treated half. In oviposition choice tests with whole plants in the greenhouse, females laid four times more eggs on untreated plants than on treated plants and the number of eggs on bolls was five times higher for untreated plants than for treated plants. Kaolin treatments altered the distribution of eggs among plant parts, with untreated bolls receiving a higher percentage than treated bolls, whereas the opposite occurred for petioles. In field tests, treatment with kaolin alone reduced the proportion of bolls infested with pink bollworm, but a mixture of kaolin and the pyrethroid lambda-cyhalothrin was most effective. The results suggest that kaolin particle film may be useful against pink bollworm, particularly in conjunction with other control tactics.


Subject(s)
Gossypium/parasitology , Kaolin/pharmacology , Larva/drug effects , Lepidoptera/drug effects , Lepidoptera/physiology , Oviposition/drug effects , Agriculture/instrumentation , Agriculture/methods , Animals , Larva/physiology
9.
Occup Health Saf ; 69(10): 230, 232-4, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11056928

ABSTRACT

Drug testing has proven to be an effective safety strategy. With proper planning, implementation, and technical expertise, a company can enjoy the benefits of a drug-free workplace. Should you wish to outsource this responsibility, there are some very good Program Administrators throughout the country, some national in scope and some regional. When recruiting an administrator, make sure it is capable of satisfying your needs. These may include a national collection site network with one fee for all your locations and with appointment scheduling, Medical Review Officers on staff with 24-hour availability, custom or standard policy and procedure manuals, training capabilities, the computing ability to customize your program, and the references to back up what the administrator claims. (Fact: If you don't test for drugs and all other employers in your area do, where do you think the drug users work?)


Subject(s)
Substance Abuse Detection/standards , Humans , Occupational Health , Policy Making , Substance Abuse Detection/methods
10.
J Econ Entomol ; 93(3): 788-94, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10902331

ABSTRACT

Insecticides are used extensively on lettuce, Lactuca sativa L., grown in southwestern Arizona because of heavy insect pressure that can potentially reduce lettuce productivity. Multiple sprays are made per season to manage these insects in lettuce. One of the major concerns related to extensive insecticide applications in lettuce is the potential subtle impact of insecticides that may reduce lettuce photosynthesis and yield. We conducted field and greenhouse experiments to examine the impact of multiple insecticides and surfactant spray applications on lettuce photosynthesis and yield. Lettuce was planted in the field in 1998, insecticides and surfactant were applied, and lettuce gas-exchange and dry weights were determined. Treatments were arranged in a split-plot consisting of insecticides as main plot and surfactant as subplot treatments in a randomized complete block design with four replications. Photosynthetic rates of lettuce were significantly reduced by endosulfan, methomyl, acephate, and surfactant at seedling stage 4 h and 2 d after the spray application was made. However, the reduction in lettuce photosynthesis by these insecticides and surfactant was only transient, and lettuce photosynthesis recovered 5 d after the spray application was made. Photosynthetic rates were not altered by zeta-cypermethrin, emamectin benzoate, and spinosad at the seedling stage. Insecticides or surfactant (Kinetic, a nonionic surfactant) did not significantly affect lettuce photosynthesis after rosette formation. In addition, lettuce dry weight was not significantly altered. These studies suggest that lettuce photosynthesis may be susceptible to some insecticides at the seedling stage. Consequently, we found that biorational insecticides, introduced to manage insect pests in lettuce, have no influence on lettuce physiology at the seedling stage, unlike the chlorinated hydrocarbons, organophosphates, or carbamates tested in this study. In a greenhouse study, we found that lettuce photosynthesis and yield were not altered by Bacillus thuringiensis application. Our results indicate that B. thuringiensis and the newer insecticides, particularly biorationals, can be used to manage lettuce insect pests without significantly altering lettuce gas-exchange and yield.


Subject(s)
Insect Control/methods , Insecticides , Lactuca/physiology , Surface-Active Agents , Animals , Crops, Agricultural
13.
Future Child ; 4(2): 119-34, 1994.
Article in English | MEDLINE | ID: mdl-7804760

ABSTRACT

Physicians become involved in child sexual abuse when they must report suspected abuse or when they are asked to medically evaluate a child who is an alleged victim of abuse. This article reviews recent progress in the medical profession's attention to child sexual abuse and discusses current issues surrounding reporting and medical evaluation. The reporting requirement raises several concerns for pediatricians. Their legal responsibilities as reporters may conflict with their traditional relationship with the family as a unit and with the confidentiality of the doctor-patient relationship. Knowledge about pediatric anogential anatomy is in a relatively early stage of development, and few pediatricians receive training adequate to enable them to determine whether medical observations are consistent with sexual abuse. Even fewer pediatricians receive training in the unique considerations and needs present when taking the medical history of a possible abuse victim or when preserving evidence for possible later use in court. The medical evidentiary evaluation of suspected sexual abuse also raises a number of concerns. There is great variability in referral patterns, which determine whether a medical examination will be requested and whether a general practice physician or a specialist will be asked to conduct the exam. Although professional medical associations have laid out broad outlines of recommended procedures for medical exams when sexual abuse is suspected, more detailed protocols are needed for addressing the many cases where findings are ambiguous or subtle. Often physicians need training in forensics and assistance in coordinating services with multiple agencies and professions. Finally, attention must be given to ensuring adequate cost reimbursement for medical evaluations.


Subject(s)
Child Abuse, Sexual/legislation & jurisprudence , Physician's Role , Child , Child Abuse, Sexual/history , Child Advocacy , Child, Preschool , History, 20th Century , Humans , United States
14.
Pediatrics ; 90(2 Pt 1): 265-72, 1992 Aug.
Article in English | MEDLINE | ID: mdl-1641294

ABSTRACT

The purpose of this study was to describe and analyze the characteristics of, and the clinical correlates to, concave hymenal variations in a large number of suspected child sexual abuse victims. Thirteen hundred eighty-three female child and adolescent suspected sexual abuse victims were comprehensively evaluated. Photocolposcopy was used for the anogenital examinations. Concave hymenal variations were found in 174 patients (12.6%). Sixty-one (35.1%) were anterior. Of these, 40 (65.6%) were curved and smooth, and 21 (34.4%) were angular and/or irregular. One hundred (57.5%) were posterior/lateral. Of these, 33 (33%) were curved and smooth, and 67 (67%) were angular and/or irregular. Thirteen patients (7.5%) had multiple hymenal concavities. Posterior/lateral location was associated with penile-vaginal contact (P = .004), penetration (P = .006), stranger perpetrator (P = .032), hymenal rim narrowing (P less than .001), and posterior fourchette abnormality (P = .049). Angular and/or irregular features were associated with penile contact (P = .005), vaginal contact (P = .035), penile-vaginal contact specifically (P less than .001), penetration (P = .046), abnormal general physical examination (P = .018), and hymenal rim narrowing (P less than .001). Logistic regression analysis demonstrated that age-specific prevalence trends for posterior/lateral (P less than .001) and angular and/or irregular (P = .011) concavities were consistent with acquired anatomic findings. An interobserver exercise with five "blinded" raters evaluating photographs of 49 patients showed significant agreement among observers in sorting posterior/lateral and angular concavities into the diagnostic categories "suggestive of trauma" and "trauma."(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Child Abuse, Sexual/pathology , Hymen/pathology , Adolescent , Age Factors , Child , Child Abuse, Sexual/diagnosis , Coitus , Colposcopy , Female , Humans , Hymen/anatomy & histology , Hymen/injuries , Logistic Models , Multivariate Analysis , Observer Variation , Prevalence , Vagina/injuries , Vagina/pathology
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