Effects of Inorganic Fertilizers on Virulence of the Entomopathogenic Nematode Steinernema glaseri and Peanut Germination under Field Conditions

The use of entomopathogenic nematodes as safe biopesticidal alternatives to hazardous chemicals entails improving the prediction of their native efficacy against soil pests. The effect of ten inorganic fertilizers, used extensively in Egypt, on the virulence of indigenous Steinernema glaseri and peanut germination was examined herein. The nematode added either before or tank-mixed with 1%, 5%, and 10% concentrations of each fertilizer in a peanut field was sampled 1 and 7 days before and 1, 7, 14, 21, 28, 49, and 56 post-tank mixes to check for S. glaseri virulence via baiting soil with Galleria mellonella larvae. Phosphorus fertilizers had more adverse effects than others on S. glaseri virulence and peanut germination. Plots with only S. glaseri had high germination close to chlorpyrifos. Averages of insect mortality in soil samples of potassium, nitrogen: phosphorus: potassium (NPK), nitrogenous, and phosphorus fertilizers, and non-fertilized checks (nematode only) were 85.8, 83.8, 80, 69.2%, and 93.3% respectively. Using S. glaseri is preferred before fertilizing. Most 1% fertilizer concentrations are compatible with S. glaseri in tank mixes for short-term (1–7 days) insect control but may affect long-term control.

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Intraspecific variation among isolates of the entomopathogenic nematode Steinernema feltiae from Bull Island, Ireland

Nematology ◽

10.1163/156854109x447015 ◽

2009 ◽

Vol 11 (3) ◽

pp. 439-451 ◽

Cited By ~ 4

Author(s):

Martin Downes ◽

Conor Meade ◽

Stephen Boyle ◽

Alec Rolston ◽

Thomae Kakouli-Duarte

Keyword(s):

Intraspecific Variation ◽

Galleria Mellonella ◽

Insect Pests ◽

Entomopathogenic Nematode ◽

Laboratory Culture ◽

Steinernema Feltiae ◽

Host Insect ◽

Large Numbers ◽

Insect Mortality ◽

Control Insect

AbstractThe application of large numbers of entomopathogenic nematodes (EPN) to control insect pests of agriculture is likely to have an impact on the local EPN fauna, yet little is known about the intraspecific relationships between EPN populations, particularly with regard to phylogeny and outbreeding. Here we assess the fitness, with regards to fecundity, host insect mortality and time taken to produce progeny, of isolates of Steinernema feltiae from Bull Island, Ireland. Exon-primed, intron-crossing (EPIC) PCR was used to examine intraspecific phylogenies between S. feltiae isolates, and identified up to three possible colonisation events of Bull Island. EPIC-PCR grouped two isolates, 33.D.(2) and 59.F.(2), separately from the remaining ten S. feltiae isolates These same two isolates consistently performed poorly in all fitness assessments. Following the crossbreeding of all isolates in Galleria mellonella, the number of host cadavers exhibiting emerging infective juveniles was significantly fewer than expected and there were significant differences between isolates in the number of days until progeny were observed. Host insect mortality varied between 40 and 87%. Such intraspecific variation may be a result of adaptation to different microhabitats of Bull Island, which in turn may be accentuated by laboratory culture practices.

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Genetic adaptation and founder effect in laboratory populations of the entomopathogenic nematode Steinernema glaseri

Canadian Journal of Zoology ◽

10.1139/z96-021 ◽

1996 ◽

Vol 74 (1) ◽

pp. 164-170 ◽

Cited By ~ 35

Author(s):

Robin J. Stuart ◽

Randy Gaugler

Keyword(s):

Founder Effect ◽

Galleria Mellonella ◽

Entomopathogenic Nematode ◽

Reproductive Potential ◽

Laboratory Culture ◽

Popillia Japonica ◽

Founder Effects ◽

Japanese Beetle ◽

Laboratory Adaptation ◽

Steinernema Glaseri

Laboratory culture can have detrimental effects on populations through adverse environmental conditions such as poor nutrition or disease, or through genetic effects such as inbreeding depression, founder effect, genetic drift, or laboratory adaptation. We tested for laboratory effects on the entomopathogenic nematode Steinernema glaseri (Steiner) by forming a genetically diverse base population from a series of field isolates and rearing several independent lines through 12 cycles of laboratory culture, using larvae of the greater wax moth, Galleria mellonella (L.), or the Japanese beetle, Popillia japonica Newman, as hosts. Laboratory bioassays based on G. mellonella indicated that lines maintained with large breeding populations did not deteriorate but often showed significant increases in infectivity (15.3–48.0%), proportion of males (12.2–36.1%), and reproductive potential (39.0–160.4%). Lines reared on P. japonica larvae responded similarly to lines reared on G. mellonella but showed higher levels of reproductive potential. Two of three lines subjected to initial genetic bottlenecks to test for founder effects differed from other lines by showing very high infectivity but little change in sex ratio or reproductive potential. These results demonstrate that laboratory adaptation can produce dramatic changes in important biological attributes of these nematodes, but that a lack of genetic variation associated with founder effects can impede this process. Laboratory adaptation should be considered a potent factor when designing, interpreting, and comparing studies of this important group of biological control organisms.

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Long-term influence of organic and inorganic fertilizers on nutrient build-up and their relationship with microbial properties under a rice-wheat cropping sequence in an acid alfisol

Acta Agronomica Hungarica ◽

10.1556/aagr.57.2009.3.5 ◽

2009 ◽

Vol 57 (3) ◽

pp. 297-306 ◽

Cited By ~ 1

Author(s):

P. Bedi ◽

Y. Dubey

Keyword(s):

Wheat Straw ◽

Green Manure ◽

Soil Samples ◽

Microbial Count ◽

Inorganic Fertilizers ◽

Microbial Properties ◽

Cropping Sequence ◽

Organic And Inorganic Fertilizers ◽

Nitrogen Phosphorus

The long-term effect of organic and inorganic fertilizers on nutrient build-up and their relationship with microbial properties in a rice-wheat cropping sequence were studied in surface (0–15 cm) and subsurface (15–30 cm) soil samples. This experiment has been in progress since 1990 in the Department of Agronomy, CSK, Palampur with twelve treatments involving combinations of organic and inorganic fertilizers. In these treatment combinations, 25 and 50% of the recommended nitrogen levels were supplemented with organic sources, i.e. FYM (farm yard manure), green manure and wheat straw. The buildup of organic matter, and the total and available pools of nitrogen, phosphorus and sulphur were determined in surface (0–15 cm) and subsurface (15–30 cm) soil samples. The substitution of 25 and 50% nitrogen through organic fertilizers proved to be better than inorganic fertilizers alone. Amongst the organic sources, the substitution of FYM resulted in higher organic carbon, total and available nitrogen, phosphorus and sulphur than green manure or wheat straw. The substitution of 50% nitrogen through organic fertilizer was more effective than the substitution of 25% nitrogen. The relationships between the total and available pools of nutrients and the total microbial count, biomass carbon, microbial respiration, and the dehydrogenase and phosphatase enzymes were studied. The total pool of nutrients showed a high, positive, significant relationship with all these parameters.

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Long-term dynamics of infectiousness within the infective-stage pool of the entomopathogenic nematode Steinernema feltiae (Site 76 strain) Filipjev

Parasitology ◽

10.1017/s0031182096008426 ◽

1997 ◽

Vol 114 (3) ◽

pp. 301-308 ◽

Cited By ~ 19

Author(s):

D. A. BOHAN ◽

W. M. HOMINICK

Keyword(s):

Population Structure ◽

Time Course ◽

Galleria Mellonella ◽

Entomopathogenic Nematode ◽

Steinernema Feltiae ◽

Infective Juvenile ◽

Future Research ◽

Infection Model ◽

Ecological Implications

Infection experiments were conducted to assess the proportion of Steinernema feltiae (Site 76 strain) Filipjev infective juveniles which penetrated into the test host Galleria mellonella L. over an 8-week period. Using a combined ANOVA and infection model approach, the analyses showed that the proportion of infective juveniles which penetrated into the test hosts changed significantly over time. This change was found to be consistent with a fluctuation in the size of a non-infectious population structure within the infective juvenile pool. These fluctuations in the magnitude of the infectious structure would dynamically alter the number of juveniles available for infection in hosts and so impose the observed change in the proportion of juveniles penetrating into hosts, over the 8-week time-course. The empirical and ecological implications of such a dynamically limited pattern of infection and possible future research into the mechanisms responsible for the non-infectious population structure are discussed.

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Influence of long-term use of various doses of mineral fertilizers on the productivity of grain-fallow crop rotation in the arid steppe of the Volga region

The Agrarian Scientific Journal ◽

10.28983/asj.y2021i8pp49-56 ◽

2021 ◽

pp. 49-56

Author(s):

Tatiana Mikhailovna Yaroshenko ◽

Dmitry Yurevich Zhuravlev ◽

Nadezhda Fedorovna Klimova

Keyword(s):

Crop Rotation ◽

Nitrate Nitrogen ◽

Mineral Fertilizers ◽

Phosphorus Fertilizers ◽

Southern Chernozem ◽

Arid Steppe ◽

High Doses ◽

Nitrogen Phosphorus ◽

Minimum Medium

The work reflects the analysis of changes in the productivity of crops of crop rotation during the long-term use of fertilizer systems in a stationary experiment for the period from VI to VIII rotation (1999-2001 - 2016-2018). The influence of various doses of nitrogen, phosphorus and nitrogen-phosphorus fertilizers on the change in the content of nitrate nitrogen and mobile phosphorus in the conditions of the southern chernozem for the specified period of research was determined. The responsiveness of crop rotation crops to the application of nitrogen, phosphorus, and nitrogen-phosphorus fertilizers in minimum, medium and high doses has been established.

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Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

Behavioral and Brain Sciences ◽

10.1017/s0140525x15000928 ◽

2016 ◽

Vol 39 ◽

Author(s):

Mary C. Potter

Keyword(s):

Working Memory ◽

Rapid Serial Visual Presentation ◽

Language Comprehension ◽

Short Term Memory ◽

Visual Presentation ◽

Long Term Memory ◽

Short Term ◽

Term Memory ◽

Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

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Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159412 ◽

1990 ◽

Vol 48 (3) ◽

pp. 374-375

Author(s):

D.E. Loudy ◽

J. Sprinkle-Cavallo ◽

J.T. Yarrington ◽

F.Y. Thompson ◽

J.P. Gibson

Keyword(s):

Antidepressant Drug ◽

Beagle Dogs ◽

Long Term Effects ◽

Short Term ◽

Platelet Counts ◽

Toxicological Studies ◽

Induced Aggregation ◽

Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

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Comparison of Auditory, Language, Memory, and Attention Abilities in Children With and Without Listening Difficulties

American Journal of Audiology ◽

10.1044/2020_aja-20-00018 ◽

2020 ◽

Vol 29 (4) ◽

pp. 710-727

Author(s):

Beula M. Magimairaj ◽

Naveen K. Nagaraj ◽

Alexander V. Sergeev ◽

Natalie J. Benafield

Keyword(s):

Auditory Processing ◽

Short Term Memory ◽

Group Differences ◽

Long Term Memory ◽

Short Term ◽

Significant Group ◽

Term Memory ◽

Memory And Attention ◽

Speed And Accuracy

Objectives School-age children with and without parent-reported listening difficulties (LiD) were compared on auditory processing, language, memory, and attention abilities. The objective was to extend what is known so far in the literature about children with LiD by using multiple measures and selective novel measures across the above areas. Design Twenty-six children who were reported by their parents as having LiD and 26 age-matched typically developing children completed clinical tests of auditory processing and multiple measures of language, attention, and memory. All children had normal-range pure-tone hearing thresholds bilaterally. Group differences were examined. Results In addition to significantly poorer speech-perception-in-noise scores, children with LiD had reduced speed and accuracy of word retrieval from long-term memory, poorer short-term memory, sentence recall, and inferencing ability. Statistically significant group differences were of moderate effect size; however, standard test scores of children with LiD were not clinically poor. No statistically significant group differences were observed in attention, working memory capacity, vocabulary, and nonverbal IQ. Conclusions Mild signal-to-noise ratio loss, as reflected by the group mean of children with LiD, supported the children's functional listening problems. In addition, children's relative weakness in select areas of language performance, short-term memory, and long-term memory lexical retrieval speed and accuracy added to previous research on evidence-based areas that need to be evaluated in children with LiD who almost always have heterogenous profiles. Importantly, the functional difficulties faced by children with LiD in relation to their test results indicated, to some extent, that commonly used assessments may not be adequately capturing the children's listening challenges. Supplemental Material https://doi.org/10.23641/asha.12808607

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