Residual Effects of Insecticides on Deraeocoris brevis (Hemiptera: Miridae)

2019 ◽  
Vol 113 (2) ◽  
pp. 770-778
Author(s):  
Kaushalya G Amarasekare ◽  
Peter W Shearer

Abstract Deraeocoris brevis (Uhler) is a key predatory natural enemy of insects and mites in pear orchards in the United States. Insecticides used for crop protection in pear orchards and their residues can negatively affect populations of D. brevis. The focus of this study was to investigate the field-aged residual effects of lambda-cyhalothrin, spinetoram, and chlorantraniliprole insecticides on D. brevis through contact exposure. An airblast sprayer was used to apply the high label rate of insecticides on pear trees. Leaves were collected from the experimental trees at 1 d after treatment (DAT) and then at 7-d intervals up to 21 DAT. Adults and nymphs were exposed to leaves with insecticide residues or untreated control for 72 h in the laboratory. The nymphs that survived the treatments were reared until they emerged as adults. The surviving paired adults were reared until death. The treated nymphs were assessed for acute mortality, survival, developmental time, and the sex ratio if they emerged as adults. The treated adults were assessed for acute and chronic mortality, fecundity, fertility, and longevity. Both nymphs and adults exposed to leaf residues of lambda-cyhalothrin had significantly higher acute mortality compared with the insects exposed to the control. When compared with the control treatment, the toxicity of field-aged residues of lambda-cyhalothrin, chlorantraniliprole, and spinetoram can persist over a longer period of time. Similar patterns were observed in previous laboratory and field experiments on D. brevis. We discuss the residual effects of three insecticides through contact exposure of D. brevis.

2019 ◽  
Vol 112 (5) ◽  
pp. 2109-2115 ◽  
Author(s):  
Kaushalya G Amarasekare ◽  
Preston H Brown ◽  
Peter W Shearer

Abstract We studied the direct (lethal) and indirect (sublethal) effects of field-aged insecticide residues of spinetoram, chlorantraniliprole and lambda-cyhalothrin on adults and larvae of the green lacewing, Chrysoperla johnsoni Henry, Wells and Pupedis an important generalist predator in western United States pear orchards. We applied formulated pesticides using their high label rates mixed with 935 liters/ha of water on pear trees utilizing an airblast sprayer. We collected leaves from the experiment trees at 1, 7, 14, 21 days after treatment (DAT) and exposed C. johnsoni adults and second instars to insecticide residues or untreated control for 72 h. We monitored larvae that survived the treatments until adult emergence (for larvae) or adults until death (for paired adults). We assessed the adults for acute and chronic mortality, longevity, fecundity, and fertility, and larvae for acute mortality, sex ratio, developmental time, and survival of adults emerged from treated second instars, to determine lethal and sublethal effects. The field-exposed insecticide residues of chlorantraniliprole exhibited higher lethal and sublethal toxicities on C. johnsoni during the 21-d leaf collection period when compared with the field-exposed residue toxicities of lambda-cyhalothrin and spinetoram. The field-exposed residue of lambda-cyhalothrin and spinetoram exhibited moderate toxicities on C. johnsoni during the 21-d leaf collection period. Results from this study show similar trends with previous studies using multiple routes of exposure laboratory assays and field experiments on Chrysoperla sp. The direct and indirect effects of field-aged residues of spinetoram, chlorantraniliprole, and lambda-cyhalothrin on C. johnsoni are discussed.


Plant Disease ◽  
2020 ◽  
Vol 104 (6) ◽  
pp. 1736-1743
Author(s):  
Yuba R. Kandel ◽  
Carl A. Bradley ◽  
Martin I. Chilvers ◽  
Febina M. Mathew ◽  
Albert U. Tenuta ◽  
...  

In total, 52 uniform field experiments were conducted in Illinois, Indiana, Iowa, Michigan, South Dakota, and Wisconsin in the United States and Ontario, Canada from 2013 to 2017 comparing crop protection products against sudden death syndrome (SDS) of soybean. Data were analyzed using meta-analytic models to summarize the relationship between foliar disease index (FDX) and yield. For each study, correlation and regression analyses were performed separately to determine three effect sizes: Fisher’s transformation of correlation coefficients (Z r ), intercept (β0), and slope (β1). Random- and mixed-effect meta-analyses were used to summarize the effect sizes. Study- and location-specific moderator variables FDX (low < 10% and high ≥ 10%), date of planting (early = prior to 7 May, conventional = 7 to 21 May, and late = after 21 May) cultivar (susceptible and partially resistant to SDS), study location, and growing season were used as fixed effects. The overall mean effect sizes of transformed correlation coefficient [Formula: see text] r was −0.41 and different from zero (P < 0.001), indicating that yield was negatively correlated with FDX. The [Formula: see text] r was affected by disease level (P < 0.01) and cultivar (P = 0.02), with a greater effect at higher disease levels and with susceptible cultivars. The mean [Formula: see text] 0 was 4,121 kg/ha and mean [Formula: see text] 1 was −21 kg/ha/% FDX and were different from zero (P < 0.01). Results from these data indicate that, for every unit of FDX increase, yield was decreased by 0.5%. Study locations and year affected the [Formula: see text] 0 , whereas none of the moderator variables significantly affected [Formula: see text] 1.


2020 ◽  
Vol 57 (3) ◽  
pp. 199-210
Author(s):  
Rajib Kundu ◽  
Mousumi Mondal ◽  
Sourav Garai ◽  
Ramyajit Mondal ◽  
Ratneswar Poddar

Field experiments were conducted at research farm of Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India (22°97' N latitude and 88°44' E longitude, 9.75 m above mean sea level) under natural weed infestations in boro season rice (nursery bed as well as main field) during 2017-18 and 2018-19 to evaluate the herbicidal effects on weed floras, yield, non-target soil organisms to optimize the herbicide use for sustainable rice-production. Seven weed control treatments including three doses of bispyribac-sodium 10% SC (150,200, and 250 ml ha-1), two doses of fenoxaprop-p-ethyl 9.3% EC (500 and 625 ml ha-1), one weed free and weedy check were laid out in a randomized complete block design, replicated thrice. Among the tested herbicides, bispyribac-sodium with its highest dose (250 ml ha-1) resulted in maximum weed control efficiency, treatment efficiency index and crop resistance index irrespective of weed species and dates of observation in both nursery as well as main field. Similar treatment also revealed maximum grain yield (5.20 t ha-1), which was 38.38% higher than control, closely followed by Fenoxaprop-p-ethyl (625 ml ha-1) had high efficacy against grasses, sedge and broadleaf weed flora. Maximum net return (Rs. 48765 ha-1) and benefit cost ratio (1.72) were obtained from the treatment which received bispyribac-sodium @ 250 ml ha-1. Based on overall performance, the bispyribac-sodium (250 ml ha-1) may be considered as the best herbicide treatment for weed management in transplanted rice as well as nursery bed.


2020 ◽  
Author(s):  
Richard P Bartlett ◽  
Alexandria Watkins

UNSTRUCTURED Background: This is an outpatient case study that examines two patients in the United States with unique cases that involve oncology, hypertension, Type II Diabetes Mellitus, and Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), also known as COVID-19. This case study involves two patients in the outpatient setting - treated via telemedicine, with laboratory-confirmed SARS-CoV-2 infection in the West Texas region between March 29th, 2020, and May 14th, 2020. Case Report: The first patient is a 63-year-old female, non-smoker, who is diagnosed with Waldenstrom’s Macroglobulinemia (2012) and Primary Cutaneous Marginal Zone Lymphoma (2020) and the second patient is a 38-year-old male, non-smoker, who has the following comorbidities: Type II Diabetes Mellitus (DM), hypertension, and gout. Both patients were empirically started on budesonide 0.5mg nebulizer twice daily, clarithromycin (Biaxin) 500mg tab twice daily for ten days, Zinc 50mg tab twice daily, and aspirin 81mg tab daily. Both patients have fully recovered with no residual effects. Conclusion: The goal is to call attention to the success of proactive, early empirical treatment, combining a classic corticosteroid (budesonide) administered via a nebulizer and an oral macrolide antibiotic known as clarithromycin (Biaxin).


2021 ◽  
pp. 1-21
Author(s):  
Jose H. S. de Sanctis ◽  
Amit J. Jhala

Abstract Velvetleaf is an economically important weed in agronomic crops in Nebraska and the United States. Dicamba applied alone usually does not provide complete velvetleaf control, particularly when velvetleaf is greater than 15 cm tall. The objectives of this experiment were to evaluate the interaction of dicamba, fluthiacet-methyl, and glyphosate applied alone or in a mixture in two- or three-way combinations for velvetleaf control in dicamba/glyphosate-resistant (DGR) soybean and to evaluate whether velvetleaf height (≤ 12 cm or ≤ 20 cm) at the time of herbicide application influences herbicide efficacy, velvetleaf density, biomass, and soybean yield. Field experiments were conducted near Clay Center, Nebraska in 2019 and 2020. The experiment was arranged in a split-plot with velvetleaf height (≤ 12 cm or ≤ 20 cm) as the main plot treatment and herbicides as sub-plot treatment. Fluthiacet provided ≥ 94% velvetleaf control 28 d after treatment (DAT) and ≥ 96% biomass reduction regardless of application rate or velvetleaf height. Velvetleaf control was 31% to 74% at 28 DAT when dicamba or glyphosate was applied alone to velvetleaf ≤ 20 cm tall compared with 47% to 100% control applied to ≤ 12 cm tall plants. Dicamba applied alone to ≤ 20 cm tall velvetleaf provided < 75% control and < 87% biomass reduction 28 DAT compared with ≥ 90% control with dicamba at 560 g ae ha−1 + fluthiacet at 7.2 g ai ha−1 or glyphosate at 1,260 g ae ha−1. Dicmaba at 280 g ae ha−1 + glyphosate at 630 g ae ha−1 applied to ≤ 20 cm tall velvetleaf resulted in 86% control 28 DAT compared with the expected 99% control. The interaction of dicamba + fluthiacet + glyphosate was additive for velvetleaf control and biomass reduction regardless of application rate and velvetleaf height.


Toxics ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 61
Author(s):  
Joseph Belsky ◽  
David J. Biddinger ◽  
Neelendra K. Joshi

Blue orchard bees, [Osmia lignaria (Say) (Hymenoptera: Megachilidae)], have been developed as an important pollinator for orchard crops in North America over the last 40 years. The toxicity of several pesticides to O. lignaria and other Osmia species has been previously reported. However, the field-realistic toxicity of formulated premix insecticides comprised of multiple active ingredients (each with a different mode of action) to O. lignaria has not been assessed. Here, we use a customized spray tower in a laboratory setting to assess adult male and female whole-body direct contact exposure to four formulated pesticide mixtures: thiamethoxam + lambda-cyhalothrin (TLC), imidacloprid + beta-cyfluthrin (IBC), chlorantraniliprole + lambda-cyhalothrin (CLC) and methoxyfenozide + spinetoram (MS) by directly spraying anesthetized bees in Petri dishes. Separately, adult male and female whole-body direct contact exposure to formulated imidacloprid (I), beta-cyfluthrin (BC) and their 1:1 binary combination (IBC) was assessed using the same experimental method. Resulting mortality in each study was screened up to 96 h post-treatment to determine acute whole-body contact toxicity. In the first study, TLC and IBC resulted in statistically higher mortality at 24 and 48 h than the two other insecticide combinations tested. The CLC and MS combinations were slower acting and the highest mortality for O. lignaria exposed to these mixtures was recorded at 96 h. We did observe significant differences in toxicity between CLC and MS. In the second study, exposure to the 1:1 binary combination of IBC caused overall significantly higher mortality than exposure to I or BC alone. Both active ingredients alone, however, demonstrated equivalent levels of mortality to the 1:1 binary combination treatment at the 96 h observation reading, indicating increased speed of kill, but not necessarily increased toxicity. Significant differences in the onset of mortality following acute contact whole-body exposure to the formulated insecticide mixtures and individual active ingredients tested were consistently observed across all experiments in both studies.


Author(s):  
Meritxell Pérez-Hedo ◽  
Carolina Gallego ◽  
Amy Roda ◽  
Barry Kostyk ◽  
Mónica Triana ◽  
...  

Abstract The predatory mirid Macrolophus praeclarus is widely distributed throughout the Americas, and is reported to prey upon several horticultural pest species. However, little is known about its biology, thermal requirements, crop odour preferences, phytophagy, and capability to induce defensive responses in plants. When five temperatures studied (20, 25, 30, 33 and 35°C) were tested and Ephestia kuehniella was used as prey, the developmental time from egg to adult on tomato, was longest at 20°C (56.3 d) and shortest at 33°C (22.7 d). The ability of nymphs to develop to adults decreased as the temperature increased, with the highest number of nymphs reaching the adult stage at 20°C (78.0%) and lowest at 35°C (0%). The lower and upper developmental thresholds were estimated at 11.2° and 35.3°C, respectively. The maximum developmental rate occurred at 31.7°C and the thermal constant was 454.0 ± 8.1 degree days. The highest predation rate of E. kuehniella eggs was obtained at 30°C. In Y-tube olfactory choice tests, M. praeclarus selected tomato, sweet pepper and eggplant odours more frequently than no plant control treatment. Macrolophus praeclarus feeding did not damage tomato plants compared to another zoophytophagous mirid, Nesidiocoris tenuis, which caused necrotic rings. The phytophagy of M. praeclarus induced defensive responses in tomato plants through the upregulation of the jasmonic acid metabolic pathway. The implications of the findings for using M. praeclarus in tomato biological control programmes in the Americas are discussed.


Plant Disease ◽  
2011 ◽  
Vol 95 (3) ◽  
pp. 263-268 ◽  
Author(s):  
S. K. Gremillion ◽  
A. K. Culbreath ◽  
D. W. Gorbet ◽  
B. G. Mullinix ◽  
R. N. Pittman ◽  
...  

Field experiments were conducted in 2002 to 2006 to characterize yield potential and disease resistance in the Bolivian landrace peanut (Arachis hypogaea) cv. Bayo Grande, and breeding lines developed from crosses of Bayo Grande and U.S. cv. Florida MDR-98. Diseases of interest included early leaf spot, caused by the fungus Cercospora arachidicola, and late leaf spot, caused by the fungus Cercosporidium personatum. Bayo Grande, MDR-98, and three breeding lines, along with U.S. cvs. C-99R and Georgia Green, were included in split-plot field experiments in six locations across the United States and Bolivia. Whole-plot treatments consisted of two tebuconazole applications and a nontreated control. Genotypes were the subplot treatments. Area under the disease progress curve (AUDPC) for percent defoliation due to leaf spot was lower for Bayo Grande and all breeding lines than for Georgia Green at all U.S. locations across years. AUDPC for disease incidence from one U.S. location indicated similar results. Severity of leaf spot epidemics and relative effects of the genotypes were less consistent in the Bolivian experiments. In Bolivia, there were no indications of greater levels of disease resistance in any of the breeding lines than in Bayo Grande. In the United States, yields of Bayo Grande and the breeding lines were greater than those of the other genotypes in 1 of 2 years. In Bolivia, low disease intensity resulted in the highest yields in Georgia Green, while high disease intensity resulted in comparable yields among the breeding lines, MDR-98, and C-99R. Leaf spot suppression by tebuconazole was greater in Bolivia than in the United States. This result indicates a possible higher level of fungicide resistance in the U.S. population of leaf spot pathogens. Overall, data from this study suggest that Bayo Grande and the breeding lines may be desirable germplasm for U.S. and Bolivian breeding programs or production.


2017 ◽  
Vol 46 (2) ◽  
pp. 315-337 ◽  
Author(s):  
Maik Kecinski ◽  
Kent D. Messer ◽  
Lauren Knapp ◽  
Yosef Shirazi

Oyster aquaculture has experienced tremendous growth in the United States over the past decade, but little is known about consumer preferences for oysters. This study analyzed preferences for oysters with varied combinations of brands, production locations, and production methods (aquaculture vs. wild-caught) using dichotomous choice, revealed preference economic field experiments. Results suggest significant and distinct differences in behavior between first-time and regular oyster consumers. While infrequent oyster consumers were drawn to oysters labeled as wild-caught, experienced oyster consumers preferred oysters raised via aquaculture. These findings will be valuable for growers and policymakers who invest in aquaculture to improve surrounding ecosystems.


2021 ◽  
Author(s):  
Eman G. Sayed ◽  
Mona A. Ouis

Abstract A new glass fertilizer (GF) system of main composition 60P2O5.30K2O.3.5ZnO. 3.5MnO.3Fe2O3 was developed in response to the needs of pea plants with bio-fertilizers (Rhizobium leguminosarum. Bv.vicieae, Bacillus megaterium var phosphaticum, Bacillus circulans).GF was prepared by the traditional melt quenching technique at 1150°C. Characterization of prepared system was done using FTIR spectra before and after immersion in a simulated actual agriculture medium like 2% citric acid and distilled water. During two winter seasons, two successful field experiments were conducted at Cairo University's Eastern Farm to determine the impact of chemical, glass, and bio-fertilizers on plant growth, yield attributes, and seed quality of pea plant. Control treatment were without any addition of recommended chemical fertilizers and other treatments were full dose of recommended chemical fertilizers (100%RDF), glass fertilizers at rate 60 kg fed− 1, Glass fertilizers at rate30 kg fed− 1, 50% RDF ,100%RDF + bio-fertilizers, Glass fertilizers at rate 60 kg fed− 1 + bio-fertilizers, glass fertilizers at rate 30 kg fed− 1+ bio-fertilizers, 50%RDF + bio-fertilizers. Plots received 60 kg fed− 1 glass fertilizers + bio-fertilizers show the highest significant increment in plant growth, number and weight of pods plant− 1, number of grain pods− 1, grain yield, biological yield, P%, k% in pea leaves and quality of pea seeds compared with plots without any addition (control) in both seasons.


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