Seasonal natural history of aphidophagous Syrphidae (Diptera) attacking the balsam twig aphid in balsam fir (Pinaceae) Christmas tree plantations

2016 ◽  
Vol 148 (4) ◽  
pp. 466-475 ◽  
Author(s):  
Richard Berthiaume ◽  
Christian Hébert ◽  
Georges Pelletier ◽  
Conrad Cloutier
Keyword(s):  
Natural History ◽  
Larval Density ◽  
Abies Balsamea ◽  
Abundant Species ◽  
Balsam Fir ◽  
Aesthetic Value ◽  
Christmas Trees ◽  
History Of ◽  
The Aesthetic ◽  
The Impact

AbstractThe balsam twig aphid, Mindarus abietinus Koch (Hemiptera: Aphididae), is one of the most important pests of balsam fir (Abies balsamea (Linnaeus) Miller; Pinaceae) grown as Christmas trees in eastern North America. Aphid feeding on the current-year shoots results in needle distortion and shoots stunting, which reduces the aesthetic value of balsam fir trees and can have substantial economic impact. Syrphidae (Diptera) fly predators attacking this aphid are poorly known. We identified four species attacking the balsam twig aphid. Syrphus torvus Osten Sacken (Diptera: Syrphidae) was the most abundant species followed by Eupeodes lapponicus (Zetterstedt) (Diptera: Syrphidae) and Eupeodes americanus (Wiedemann) (Diptera: Syrphidae). We described the seasonal natural history of the two most abundant syrphids feeding on this aphid and we studied their synchrony with their prey. Syrphid larval density on balsam fir shoots increased rapidly and closely followed density of the balsam twig aphid. We also reported heavy parasitism of syrphid pupae by two Hymenoptera on tree foliage but lower parasitism on pupae in the soil under trees. Several cases of multiple parasitism and hyperparasitism were observed in syrphid pupae under trees. Abundance of predaceous syrphid species was higher in untreated balsam fir plantations compared with treated plantations. More research is needed to understand the role and the impact of these predators on balsam twig aphid population dynamics.

Podabrus rugosulus (Coleoptera: Cantharidae), an opportunist predator of Mindarus abietinus (Hemiptera: Aphididae) in Christmas tree plantations

2001 ◽  
Vol 133 (1) ◽  
pp. 151-154 ◽  
Author(s):  
Richard Berthiaume ◽  
Christian Hébert ◽  
Conrad Cloutier
Keyword(s):  
Abies Balsamea ◽  
The United States ◽  
Balsam Fir ◽  
Tree Plantations ◽  
Christmas Tree ◽  
Eastern Canada ◽  
Aesthetic Value ◽  
Christmas Trees ◽  
Major Pest ◽  
The Aesthetic

The balsam twig aphid, Mindarus abietinus Koch, is a major pest of balsam fir, Abies balsamea (L.) Mill. (Pinaceae), grown as Christmas trees in eastern Canada and the United States (Nettleton and Hain 1982; Kleintjes 1997). This aphid has three or four generations from April to July, and overwinters as eggs on fir shoots. Mature fundatrices deposit progeny on new shoots in late May. Infested shoots develop into pseudogalls characterised by stunting and needle distortion, thus reducing the aesthetic value of trees.

Stochastic simulation of growth loss in thinned balsam fir stands defoliated by the spruce budworm in Newfoundland

1998 ◽  
Vol 28 (5) ◽  
pp. 703-710 ◽  
Author(s):  
Erhard John Dobesberger
Keyword(s):  
Stochastic Simulation ◽  
Larval Density ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Damage Function ◽  
Balsam Fir ◽  
Negative Exponential Function ◽  
Attack Pattern ◽  
Growth Loss ◽  
The Impact

A stochastic simulation model was developed to derive a damage function for the spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), and balsam fir, Abies balsamea (L.) Mill., herbivore interaction at the stand level for open-grown trees. Both aggregated and uniform models of attack pattern by late-instar larvae based on k of the negative binomial were evaluated to determine the impact of larval density and attack pattern on the loss in stemwood volume increment of young, thinned balsam fir stands in Newfoundland. Percentage loss in stemwood increment was a nonlinear, negative exponential function of initial larval density. Implementation of control measures to prevent 50% defoliation that is caused by about 14 larvae/branch tip would result in saving 24% of the annual stemwood increment after 1 year of defoliation and about 32% after 2 years of cumulative defoliation. Aggregation of spruce budworm larvae among trees within a forest stand results in less growth loss compared with a uniform pattern of attack. The nonlinear damage function may suggest tolerance and possibly compensatory growth after herbivory by low population levels of the spruce budworm.

What's the Message of Architecture?

2014 ◽  
pp. 126-136
Author(s):  
Аndrey G. Velikanov
Keyword(s):  
Separate Entity ◽  
Aesthetic Value ◽  
Current State ◽  
Entire Complex ◽  
History Of ◽  
The Aesthetic

Considers the aspects of architecture as a language able to express the current state and to prophetically indicate the upcoming changes. The aesthetic value of a construction cannot be perceived just as a separate entity, but it can be cognized in the context and not only a visual one, in space. It is necessary to see the entire complex of the accompanying phenomena, all the flow of the unfolding metaphors and values. In the model in view the figure of the author-creator must be reconsidered as no longer conforming to today's reality. The development of the Stalinist Empire style, as well as its transformations, is considered as one of the specific phenomena in the history of well-known constructions

scholarly journals Natural History of NAFLD

2021 ◽  
Vol 10 (6) ◽  
pp. 1161
Author(s):  
Raluca Pais ◽  
Thomas Maurel
Keyword(s):  
Liver Disease ◽  
Natural History ◽  
Disease Progression ◽  
Specific Treatment ◽  
Alcoholic Fatty Liver ◽  
Individual Level ◽  
Close Relationship ◽  
History Of ◽  
The Individual ◽  
The Impact

The epidemiology and the current burden of chronic liver disease are changing globally, with non-alcoholic fatty liver disease (NAFLD) becoming the most frequent cause of liver disease in close relationship with the global epidemics of obesity, type 2 diabetes and metabolic syndrome. The clinical phenotypes of NAFLD are very heterogeneous in relationship with multiple pathways involved in the disease progression. In the absence of a specific treatment for non-alcoholic steatohepatitis (NASH), it is important to understand the natural history of the disease, to identify and to optimize the control of factors that are involved in disease progression. In this paper we propose a critical analysis of factors that are involved in the progression of the liver damage and the occurrence of extra-hepatic complications (cardiovascular diseases, extra hepatic cancer) in patients with NAFLD. We also briefly discuss the impact of the heterogeneity of the clinical phenotype of NAFLD on the clinical practice globally and at the individual level.

scholarly journals S19 The impact of clotting abnormalities on the natural history of idiopathic pulmonary fibrosis: an extended follow up of a population based cohort

Thorax ◽  
2016 ◽  
Vol 71 (Suppl 3) ◽  
pp. A13.1-A13
Author(s):  
V Navaratnam ◽  
AW Fogarty ◽  
T McKeever ◽  
N Thompson ◽  
G Jenkins ◽  
...  
Keyword(s):  
Natural History ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Population Based ◽  
History Of ◽  
The Impact

scholarly journals Modelling the HIV-Associated TB Epidemic and the Impact of Interventions Aimed at Epidemic Control

2019 ◽  
pp. 25-55
Author(s):  
P. J. Dodd ◽  
C. Pretorius ◽  
B. G. Williams
Keyword(s):  
Natural History ◽  
Mathematical Models ◽  
Population Level ◽  
Explicit Representation ◽  
Epidemic Control ◽  
Future Directions ◽  
Individual Level ◽  
Tuberculosis Epidemiology ◽  
History Of ◽  
The Impact

Abstract In this chapter, we focus on mathematical models of tuberculosis epidemiology (TB) that include interactions with HIV and an explicit representation of transmission. We review the natural history of TB and illustrate how its features are simplified and incorporated in mathematical models. We then review the ways HIV influences the natural history of TB, the interventions that have been considered in models, and the way these individual-level effects are represented in models. We then go on to consider population-level effects, reviewing the TB/HIV modelling literature. We first review studies whose focus was on purely epidemiological modelling, and then studies whose focus was on modelling the impact of interventions. We conclude with a summary of the uses and achievements of TB/HIV modelling and some suggested future directions.

scholarly journals Impact of Mowing Height and Nitrogen Fertility on Crabgrass Cover in ‘RTF' Tall Fescue1

2018 ◽  
Vol 36 (3) ◽  
pp. 104-107
Author(s):  
Matthew Cutulle ◽  
Jeffrey Derr ◽  
David McCall ◽  
Adam Nichols ◽  
Brandon Horvath
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Fertilization Rate ◽  
Aesthetic Value ◽  
Virginia Beach ◽  
Nitrogen Fertility ◽  
The Aesthetic ◽  
And Function ◽  
The Impact ◽  
Schedonorus Phoenix

Abstract Tall fescue (Festuca arundinacea Shreb.) has exceptional utility as a low maintenance lawn in the transition zone. However, during the summer smooth crabgrass [Digitaria ischaemum (Schreb.) Schreb. ex Muhl.] infestations can reduce the aesthetic value and function of the turf and lead to a thinning of the tall fescue stand, noticeable after the crabgrass plants have senesced. Research was conducted to evaluate the impact of mowing height and nitrogen fertility on smooth crabgrass plant counts and tall fescue cover in Virginia Beach, VA. Plots were mowed at either 6 cm (2.5 in) or 10 cm (4 in) and received 49, 171, or 220 kg of nitrogen annually per hectare (44, 152, and 196 lb.A−1). Mowing at 10 cm with the highest level of fertility resulted in the most turfgrass cover among all the treatment combinations. Mowing at 10 cm as opposed to 6 cm resulted in less smooth crabgrass plants, regardless of nitrogen fertilization rate. Index words: fertilization, turfgrass, weed control. Species used in this study: Smooth crabgrass [Digitaria ischaemum (Schreb.) Schreb. ex Muhl.]; tall fescue [Festuca arundinacea Shreb. synonym Schedonorus phoenix (Scop.) Holub].

scholarly journals From Literature to Image—Aesthetic Features of Space Megastructure Cities in American Sci-Fi Movies

2021 ◽  
Vol 7 (3) ◽  
pp. 116-121
Author(s):  
Zhi Li ◽  
Keyword(s):  
Science Fiction ◽  
Digital Design ◽  
Aesthetic Value ◽  
Scene Design ◽  
Self Help ◽  
The Future ◽  
The Aesthetic ◽  
Space Colonization ◽  
Design Style ◽  
The Impact

The concept of Space megastructures is originated from science fiction novels. They symbolize the material landscape form of a comprehensive advancement of intelligent civilization after the continuous development of technology. Space megacity is actually an expansion process of human development in the future. It is not only a transformation of space colonization but also a mapping of self-help homeland. Therefore, it is a symbol of technological optimism and a future utopia in the context of technology. In contemporary times, sci-fi movies use digital technology to translate the giant imagination in literature into richer digital image landscapes. Space giant cities are one of the most typical digital images with spectacle view, which reflects the impact of American sci-fi movie scene design on the landscape and preference that human will be living in the future. The aesthetic preferences and design principles of the future picture, and the aesthetic value of science fiction as a medium of imagination are revealed. The aim of this article is to explore the digital design style of space megastructure with utopia sense in science fiction movies, and analyzes its aesthetic connotation.

Considering the impact of pregnancy on the natural history of hidradenitis suppurativa

2017 ◽  
Vol 178 (1) ◽  
Author(s):  
P. Perng ◽  
J.G. Zampella ◽  
G.A. Okoye
Keyword(s):  
Natural History ◽  
Hidradenitis Suppurativa ◽  
History Of ◽  
The Impact

Effects of fenitrothion on the arthropod food of tree-foraging forest songbirds

1990 ◽  
Vol 68 (11) ◽  
pp. 2235-2242 ◽  
Author(s):  
Rhonda L. Millikin
Keyword(s):  
Active Ingredient ◽  
Significant Relationship ◽  
Tree Species ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Betula Papyrifera ◽  
White Birch ◽  
Forest Songbirds ◽  
The Impact

The impact of fenitrothion on the arthropod food of songbirds was measured using white birch (Betula papyrifera Marsh.) and balsam fir (Abies balsamea (L.) Mill.) branch sample and drop trays. Following ground application of fenitrothion at 293 g active ingredient/ha, there was a significant decrease in the biomass of arthropods as determined using branch samples from both tree species, but not until 5 days after the application (29% reduction for balsam fir, 35% for white birch). Samples from drop trays indicated an immediate kill of arthropods not associated with the tree. Most remaining arthropods on treated balsam fir trees were dead. These dead arthropods would not be suitable food for birds that require movement to detect their prey. There was no significant relationship between amount of deposit (treated trees only) and the reduction of arthropods for either tree species.

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