scholarly journals Spinosad and Mixtures of an Entomopathogenic Fungus and Pyrethrins for Control of Sitona lineatus (Coleoptera: Curculionidae) in Field Peas

2020 ◽  
Vol 113 (2) ◽  
pp. 669-678 ◽  
Author(s):  
Govinda Shrestha ◽  
Sindhura Mettupalli ◽  
Ramadevi Gadi ◽  
Debra A Miller ◽  
Gadi V P Reddy

Abstract The pea leaf weevil, Sitona lineatus L., is an important pest of field peas and faba beans in most temperate regions. As no information is currently available on efficacy of biopesticides for S. lineatus control, laboratory bioassays were performed to evaluate the impact of biopesticides (spinosad, Beauveria bassiana strain GHA, pyrethrins, B. bassiana GHA + pyrethrins, and B. bassiana GHA + azadirachtin) against adults of this pest. The concentrations used in this bioassay were 0.1, 0.5, 1.0, and 2.0 times the lowest labeled application rate of each product. Results were further verified in cage experiments by assessing biopesticide effects on adult mortality and feeding damage in pea plants. The impact of biopesticides on mortality of larvae of two beneficial species, Chrysoperla carnea and Adalia bipunctata, was also tested in laboratory conditions. We found spinosad to be the most promising candidate, causing 100% adult mortality at high and medium concentrations. Beauveria bassiana and its combination with pyrethrins caused 60–62% adult mortality, but only at the highest concentration. In contrast, B. bassiana + azadirachtin and pyrethrins treatments caused only minimal adult mortality at all concentrations. In cage experiments, spinosad and B. bassiana + pyrethrins had significant effects on adult mortality and provided foliage protection from adult feeding. Conversely, the fungus treatment alone showed inconsistent performance. Beauveria bassiana and spinosad were generally harmless to C. carnea and A. bipunctata larvae, but B. bassiana + pyrethrins was toxic toward beneficial species. These results could help to improve integrated pest management programs intended to control S. lineatus.

2016 ◽  
Vol 148 (5) ◽  
pp. 595-602 ◽  
Author(s):  
M.L. Evenden ◽  
C.M. Whitehouse ◽  
A. St. Onge ◽  
L. Vanderark ◽  
J.-P. Lafontaine ◽  
...  

AbstractThe pea leaf weevil, Sitona lineatus (Linnaeus) (Coleoptera: Curculionidae), is an important pest of field peas, Pisum sativum Linnaeus (Fabaceae), and faba beans, Vicia faba Linnaeus (Fabaceae), that has recently become established in the Prairie Provinces of Canada. Male pea leaf weevils produce an aggregation pheromone, 4-methyl-3,5-heptanedione, in the spring when overwintered weevils migrate to fields to feed and mate. The current study tests the attractiveness of the aggregation pheromone with and without synthetic bean volatiles to pea leaf weevils in the spring and in the fall when weevils seek perennial legumes to feed and overwinter. Modified Leggett traps similar to those used in Europe did not retain weevils in this study. Aggregation pheromone-baited pitfall traps caught male and female weevils in the spring and fall. Weevils were not attracted to traps baited with three bean volatiles, (Z)-3-hexen-1-yl acetate, (Z)-3-hexen-1-ol, and linalool. Bean volatiles did enhance response to pheromone, but only in the fall. Weevils were captured in most semiochemical-baited traps in a 1:1 sex ratio, but female-biased catch in control traps might indicate greater activity of females in the trap vicinity. This study lays the groundwork for semiochemical-based monitoring to detect pea leaf weevil spread in the Prairie Provinces.


2003 ◽  
Vol 38 (3) ◽  
pp. 359-367 ◽  
Author(s):  
Mathias Kouassi ◽  
Daniel Coderre ◽  
Silvia I. Todorova

Experiments were conducted under laboratory and field conditions to assess the effect of the fungicide Zineb (zinc dimethyl-dithiocarbamate) and the insecticide Cygon (dimethoate) on the pathogenicity of the isolate MK 2001 of Beauveria bassiana (Balsamo) Vuillemin, a potential microbial agent for biological control of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois). The isolate was highly pathogenic to adults yielding an LC50 of 7.2 × 103 conidia/mL at 6 d post treatment and an LT50 of 3.07 d at a concentration of 1 × 108 conidia/mL. Zineb inhibited the in vitro growth of the fungus in Sabouraud's dextrose broth and on Sabouraud's dextrose agar. It had no insecticidal activity against adult L. lineolaris in laboratory bioassays. A field test with caged L. lineolaris adults on lettuce Lactuca sativa L. var. longifolia, at a phenological stage of 50 leaves further demonstrated that Zineb and Dimethoate had no effect on B. bassiana against L. lineolaris. Adult mortality 10 d after application did not differ significantly in treatments with B. bassiana alone from treatments with B. bassiana + Zineb, dimethoate alone, B. bassiana + dimethoate, B. bassiana + Zineb, and B. bassiana + Zineb + dimethoate. No larva was observed in cages treated with B. bassiana alone or in combination with Zineb or dimethoate. On the contrary, 11 larvae/plant were recorded in the untreated cages and 5 larvae/plant in the dimethoate-treated cages.


Biochar ◽  
2021 ◽  
Author(s):  
Ngitheni Winnie-Kate Nyoka ◽  
Ozekeke Ogbeide ◽  
Patricks Voua Otomo

AbstractTerrestrial and aquatic ecosystems are increasingly threatened by pesticide pollution resulting from extensive use of pesticides, and due to the lack of regulatory measures in the developing world, there is a need for affordable means to lessen environmental effects. This study aimed to investigate the impact of biochar amendment on the toxicity of imidacloprid to life-cycle parameters and biomarker responses of the earthworm Eisenia fetida. E. fetida was exposed to 10% biochar-amended and non-amended OECD artificial soils spiked with 0, 0.75, 1.5, 2.25 and 3 mg imidacloprid/kg for 28 days. An LC50 of 2.7 mg/kg was only computed in the non-amended soil but not in the biochar-amended soil due to insignificant mortality. The EC50 calculated in the non-amended soil (0.92 mg/kg) for reproduction (fertility) was lower than the one computed in the biochar amended (0.98 mg/kg), indicating a decrease in toxicity in the biochar-amended substrate. Significant weight loss was observed at the two highest imidacloprid treatments in the non-amended soil and only at the highest treatment in the biochar-amended substrate, further highlighting the beneficial effects of biochar. Catalase activity decreased significantly at the two highest concentrations of non-amended soil. Yet, in the amended soil, the activity remained high, especially in the highest concentration, where it was significantly higher than the controls. This indicated more severe oxidative stress in the absence of biochar. In all non-amended treatments, there was a significant acetylcholinesterase inhibition, while lower inhibition percentages were observed in the biochar-amended soil. In most endpoints, the addition of biochar alleviated the toxic effects of imidacloprid, which shows that biochar has the potential to be useful in soil remediation. However, there is still a need for field studies to identify the most effective application rate of biochar for land application.


2003 ◽  
Vol 83 (2) ◽  
pp. 283-289 ◽  
Author(s):  
R. E. Karamanos ◽  
N. A. Flore ◽  
J. T. Harapiak

Canadian Prairie Provinces in general, and Saskatchewan in particular are major producers of peas worldwide. Individual provincial criteria for P application are considerably different from each other. Further introduction of new pea varieties and the adoption of direct seeding practices prompted us to re-evaluate these criteria. To this end, two experiments with field peas (Pisum sativum L. var. Carneval) were carried out between 1994 and 1998 at nine different locations in Alberta. The first experiment was carried out in 1994 and consisted of three trials with six rates of P (0, 4.4, 8.7, 13, 17.5 and 21.8 kg P ha-1) in the form of monoammonium phosphate (MAP) (12-51-0). To eliminate the impact of varying N rates along with P, a series of 21 trials and a uniform design that included five rates of P (0, 6.5, 13, 19.5 and 26 kg ha-1) in the form of triple super phosphate (0-45-0) and two methods of placement (seed placement or side banding) were subsequently carried out. There was a significant response to P application at all 13 sites of both experiments that contained 10 or less mg of a Modified Kelowna (MK) extractable-P kg-1 of soil. Side banding resulted in significantly higher yield in only three trials. Maximum average yield increase of 645 kg seed ha-1 was obtained with application of 19.5 kg P ha-1; it was influenced by soil texture as the magnitude of response was greater on loamy (535 kg seed ha-1) than on clay loam soils (285 kg seed ha-1). There was no significant yield increase in the trials that contained greater than 10 mg MK-P kg-1 soil. Reduction in plant population was more frequent as a result of seed placement (nine cases with P < 0.1) than side banding in both experiments. The impact of P fertilization on seed moisture was not consistent. The ability to side band or to seed with an increased seed bed utilization may fulfil the need for application of greater rates of P than the ones currently recommended for prairie soils. Key words: Seed placement, side banding, triple super phosphate, monoammonium phosphate


2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Sarayut Pittarate ◽  
Malee Thungrabeab ◽  
Supamit Mekchay ◽  
Patcharin Krutmuang

Ctenocephalides felis is an ectoparasitic flea species commonly found on dogs and cats. The current study verified the in vitro virulence of conidia of the entomopathogenic fungus Beauveria bassiana produced under different color LED light (red, blue, purple, green, yellow, and white) to adults of C. felis. The fungal isolates were cultivated on malt extract agar (MEA). Bioassay treatments used aerial conidia in test tubes. Adult fleas were obtained from a house cat in Chiang Mai province, Thailand. The experiments were composed of one control and eleven treatment groups. All of the treatments with B. bassiana conidia caused adult mortality after an exposure of 12 h. Among the conditions used in this study, B. bassiana cultured under red LED and fluorescent light were the most effective in causing mortality (100 %) in adult fleas after 36 h. The experimental results indicate that these aerial conidia of B. bassiana have promising potential for use in control of C. felis adult stages.


Critical Care ◽  
2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Shih-Chieh Chien ◽  
Chien-Yi Hsu ◽  
Hung-Yi Liu ◽  
Chao-Feng Lin ◽  
Chung-Lieh Hung ◽  
...  

Abstract Background This study investigated temporal trends in the treatment and mortality of patients with cardiogenic shock (CS) in Taiwan in relation to acute myocardial infarction (AMI) accreditation implemented in 2009 and the unavailability of percutaneous ventricular assist devices. Methods Data of patients diagnosed as having CS between January 2003 and December 2017 were collected from Taiwan’s National Health Insurance Research Database. Each case was followed from the date of emergency department arrival or hospital admission for the first incident associated with a CS diagnosis up to a 1-year interval. Measurements included demographics, comorbidities, treatment, mortality, and medical costs. Using an interrupted time-series (ITS) design with multi-level mixed-effects logistic regression model, we assessed the impact of AMI accreditation implementation on the mortality of patients with AMI and CS overall and stratified by the hospital levels. Results In total, 64 049 patients with CS (mean age:70 years; 62% men) were identified. The incidence rate per 105 person-years increased from 17 in 2003 to 25 in 2010 and plateaued thereafter. Average inpatient costs increased from 159 125 points in 2003 to 240 993 points in 2017, indicating a 1.5-fold increase. The intra-aortic balloon pump application rate was approximately 22–25% after 2010 (p = 0.093). Overall, in-hospital, 30-day, and 1-year mortality declined from 60.3%, 63.0%, and 69.3% in 2003 to 47.9%, 50.8% and 59.8% in 2017, respectively. The decline in mortality was more apparent in patients with AMI-CS than in patients with non-AMI-CS. The ITS estimation revealed a 2% lower in-hospital mortality in patients with AMI-CS treated in district hospitals after the AMI accreditation had been implemented for 2 years. Conclusions In Taiwan, the burden of CS has consistently increased due to high patient complexity, advanced therapies, and stable incidence. Mortality declined over time, particularly in patients with AMI-CS, which may be attributable to advancements in AMI therapies and this quality-improving policy.


2005 ◽  
Vol 25 (6) ◽  
pp. 431-444 ◽  
Author(s):  
VICTORIA HOSEGOOD ◽  
IAN M. TIMÆUS

This paper examines changes in households with older people in a northern rural area of KwaZulu Natal province, South Africa, between January 2000 and January 2002. The focus is the impact of adult deaths, especially those from AIDS, on the living arrangements of older people. The longitudinal data are from the Africa Centre Demographic Information System. In 2000, 3,657 older people (women aged 60 years or older, men 65 years or older) were resident in the area, and 3,124 households had at least one older member. The majority (87%) of older people lived in three-generation households. Households with older people were significantly poorer, more likely to be headed by a woman, and in homesteads with poorer quality infrastructure than households without older members. By January 2002, 316 (8%) of the older people in the sample had died. Of all the households with an older person, 12 per cent experienced at least one adult death from AIDS. The paper shows that older people, particularly those living alone or with children in the absence of other adults, were living in the poorest households. They were also coping with an increasing burden of young adult deaths, the majority of which were attributable to AIDS.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 318-318
Author(s):  
Cierra N Crowell ◽  
Erin B Perry

Abstract Work in other species has demonstrated an impact of gestational exposure on flavor preferences. Although equine palatability preferences in mature horses have been identified, feeding behaviors in growing horses are not well documented. The objective of this study was to evaluate the impact of exposure to common palatants in utero on feeding preferences of weanlings. Stock-type weanlings (n = 4) weighing 225(±18.15) kg at 29(±2.55) weeks of age were used in a side-by-side comparison test with a divided feeding platform. Common palatants (apple and anise) were utilized throughout the broodmare gestational period. A novel palatant, peppermint, was withheld during gestation to identify impacts associated with neophobic tendencies. Treatments were offered once daily for three consecutive days across three periods (4 weeks apart) using a pelleted concentrate feed with an application rate of 0.375 mL/0.23 kg. Weanlings were allowed free access to the feeding platform with identical pans spaced 6” apart for 20 minutes. Treatment location within the feeding platform was changed daily to limit effects associated with side-eating. Data were measured as a Chi Square test of SAS using PROC FREQ statement with α ≤. 0.05. Despite gestational exposure to apple and anise, no preference was measured in palatability assessments including First Sniff (P = 0.29), First Consumed (P = 0.70), First Finished (P = 0.29). These data suggest that exposure in utero failed to elicit a preference for common palatants in weanling horses. Additionally, these data fail to demonstrate a neophobic effect for a novel palatant, peppermint.


2019 ◽  
Vol 11 (17) ◽  
pp. 4799
Author(s):  
Wenting Jiang ◽  
Xiaohu Liu ◽  
Xiukang Wang ◽  
Lihui Yang ◽  
Yuan Yin

Optimizing the phosphorus (P) application rate can increase grain yield while reducing both cost and environmental impact. However, optimal P rates vary substantially when different targets such as maximum yield or maximum economic benefit are considered. The present study used field experiment conducted at 36 experiments sites for maize to determine the impact of P application levels on grain yield, plant P uptake, and P agronomy efficiency (AEP), P-derived yield benefits and private profitability, and to evaluated the agronomically (AOPR), privately (POPR), and economically (EOPR) optimal P rate at a regional scale. Four treatments were compared: No P fertilizer (P0); P rate of 45–60 kg ha−1 (LP); P rate of 90–120 kg ha−1 (MP); P rate of 135–180 kg ha−1 (HP). P application more effectively increased grain yield, reaching a peak at MP treatment. The plant P uptake in HP treatment was 37.4% higher than that in P0. The relationship between P uptake by plants (y) and P application rate (x) can be described by the equation y = −0.0003x2 + 0.1266x + 31.1 (R2 = 0.309, p < 0.01). Furthermore, grain yield (y) and plant P uptake (x) across all treatments also showed a significant polynomial function (R2 = 0.787–0.846). The MP treatment led to highest improvements in P agronomic efficiency (AEP), P-derived yield benefits (BY) and private profitability (BP) compared with those in other treatments. In addition, the average agronomically (AOPR), privately (POPR), and economically optimal P rate (EOPR) in 36 experimental sites were suggested as 127.9 kg ha−1, 110.8 kg ha−1, and 114.4 kg ha−1, which ranged from 80.6 to 211.3 kg ha−1, 78.2 to 181.8 kg ha−1, and 82.6 to 151.6 kg ha−1, respectively. Economically optimal P application (EOPR) can be recommended, because EOPR significantly reduced P application compared with AOPR, and average economically optimal yield was slightly higher compared with the average yield in the MP treatment. This study was conducive in providing a more productive, use-effective, profitable, environment-friendly P fertilizer management strategy for supporting maximized production potential and environment sustainable development.


2016 ◽  
Vol 154 (5) ◽  
pp. 812-827 ◽  
Author(s):  
M. J. BELL ◽  
J. M. CLOY ◽  
C. F. E. TOPP ◽  
B. C. BALL ◽  
A. BAGNALL ◽  
...  

SUMMARYIncreasing recognition of the extent to which nitrous oxide (N2O) contributes to climate change has resulted in greater demand to improve quantification of N2O emissions, identify emission sources and suggest mitigation options. Agriculture is by far the largest source and grasslands, occupying c. 0·22 of European agricultural land, are a major land-use within this sector. The application of mineral fertilizers to optimize pasture yields is a major source of N2O and with increasing pressure to increase agricultural productivity, options to quantify and reduce emissions whilst maintaining sufficient grassland for a given intensity of production are required. Identification of the source and extent of emissions will help to improve reporting in national inventories, with the most common approach using the IPCC emission factor (EF) default, where 0·01 of added nitrogen fertilizer is assumed to be emitted directly as N2O. The current experiment aimed to establish the suitability of applying this EF to fertilized Scottish grasslands and to identify variation in the EF depending on the application rate of ammonium nitrate (AN). Mitigation options to reduce N2O emissions were also investigated, including the use of urea fertilizer in place of AN, addition of a nitrification inhibitor dicyandiamide (DCD) and application of AN in smaller, more frequent doses. Nitrous oxide emissions were measured from a cut grassland in south-west Scotland from March 2011 to March 2012. Grass yield was also measured to establish the impact of mitigation options on grass production, along with soil and environmental variables to improve understanding of the controls on N2O emissions. A monotonic increase in annual cumulative N2O emissions was observed with increasing AN application rate. Emission factors ranging from 1·06–1·34% were measured for AN application rates between 80 and 320 kg N/ha, with a mean of 1·19%. A lack of any significant difference between these EFs indicates that use of a uniform EF is suitable over these application rates. The mean EF of 1·19% exceeds the IPCC default 1%, suggesting that use of the default value may underestimate emissions of AN-fertilizer-induced N2O loss from Scottish grasslands. The increase in emissions beyond an application rate of 320 kg N/ha produced an EF of 1·74%, significantly different to that from lower application rates and much greater than the 1% default. An EF of 0·89% for urea fertilizer and 0·59% for urea with DCD suggests that N2O quantification using the IPCC default EF will overestimate emissions for grasslands where these fertilizers are applied. Large rainfall shortly after fertilizer application appears to be the main trigger for N2O emissions, thus applicability of the 1% EF could vary and depend on the weather conditions at the time of fertilizer application.


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