scholarly journals A contribution to the study of biology of Curculio elephas Gyll. (Coleoptera, Curculionidae)

2011 ◽  
pp. 19-28
Author(s):  
Milan Drekic ◽  
Ljubodrag Mihajlovic

One of the insects that feeds on pedunculate oak acorns and reduces its seed yield is Curculio elephas Gyll. The study of Curculio elephas Gyll is necessary because of the severe damages caused by this insect and also owing to its insufficiently investigated biology. The research was conducted in the common oak seed orchard at Banov Brod, forest estate ?Sremska Mitrovica?, and in the entomological laboratory. The adults emerge from the soil chambers from mid July till the beginning of September. The presence of adults, as determined by crown fogging, ranged from the end of July till the beginning of September with the highest number in mid August. After emerging from the soil, females are already fertile with the developed eggs in the ovaries. They start egg laying after 1 to 8 days and they lay from one to seven eggs per day. Egg laying period lasts from 7 to 20 days. Fertility of C. elephas females ranges from 5 to 40 eggs, while their fecundity ranges from 19 to 45 eggs. At the end of the larval stage, larvae bore into the soil and stay there from one to three years. The species hibernates only in the larval stage. C. elephas has a one-year life cycle, while a minor part of the population has a two or three-year life cycle.

1966 ◽  
Vol 98 (7) ◽  
pp. 693-699 ◽  
Author(s):  
L. Daviault ◽  
R. Ducharme

AbstractEpinotia nanana (Tr.) has become increasingly important in recent years in Quebec as it has caused severe defoliation of ornamental spruce trees in the Berthierville area, Quebec. The insect has a one-year life cycle and overwinters in the larval stage, mainly in the fifth instar, in a mined needle. Damage is most noticeable in the spring. Fairly heavy mortality, probably due to unfavourable climatic conditions, occurs among overwintering larvae. The amount of control exerted by parasites is always low.


Author(s):  
Jan Herrmann ◽  
Miku Yoshiyama

Stormwaters’ heavy loads of nutrients, metals and oil etc, via urban ditches / streams, are increasingly treated in engineered shallow wetlands/ponds. Such approaches are still only remedying a minor part of affected storm waters, urban streams, and freshwater and marine recipients. In Kalmar, a middle-sized Swedish town at the Baltic Sea, > 10 such wetlands / ponds are established for reduction of such heavily polluted waters. Aiming at determining the effectiveness in reduction of nutrients and metals, and the facilitation of the aquatic biodiversity (primarily in the wetlands), monitoring programs were initiated. Regular in/outflow water sampling, water flow and biology, were followed for 1-2-3 years (varied with parameter) after construction in two of these wetlands. Skälby Dämme, constructed 14 years ago (2000), showed ca 40 % nutrient reduction figures, less for TSS and metals, while Hagbygärde Dämme, constructed two years ago (2012), attained only much lower results. Reasons for this difference might be that Hagbygärde is less surrounded by forested land, also that less than one year had elapsed before evaluation commenced, while two-three years in Skälby. More recent monitoring in Skälby Dämme is also compared with. Moreover, this kind of wetlands/ponds is shown to favour the biodiversity of benthic invertebrates, (aquatic) plants and birds, although with trends to decline in species richness some years after the initial colonization period.


1990 ◽  
Vol 55 ◽  
Author(s):  
N. Lust ◽  
L. Speleers

The  natural regeneration of American oak and pedunculate oak under cover occurs  regularly in the Aelmoeseneie forest. Nevertheless, these seedlings tend to  establish very difficultly. They often die off after one year. In order to  survive, the crown cover has to be strongly opened after the first year.      One year old seedlings of American oak, however, grow slightly better under  cover than under partial freestand. The seedlings of pedunculate oak, on the  other hand, hardly react on the different light conditions.     The American oak seeds are of good quality. A considerable amount is eaten  by the birds. The seeds of pedunculate oak are of a minor quality; an  important number is eaten by the worms. The growth of the seedlings in the  Aelmoeseneie forest does not always correspond to the growth on other sites.


Author(s):  
Lidiya Derbenyova

The article explores the role of antropoetonyms in the reader’s “horizon of expectation” formation. As a kind of “text in the text”, antropoetonyms are concentrating a large amount of information on a minor part of the text, reflecting the main theme of the work. As a “text” this class of poetonyms performs a number of functions: transmission and storage of information, generation of new meanings, the function of “cultural memory”, which explains the readers’ “horizon of expectations”. In analyzing the context of the literary work we should consider the function of antropoetonyms in vertical context (the link between artistic and other texts, and the groundwork system of culture), as well as in the context of the horizontal one (times’ connection realized in the communication chain from the word to the text; the author’s intention). In this aspect, the role of antropoetonyms in the structure of the literary text is extremely significant because antropoetonyms convey an associative nature, generating a complex mechanism of allusions. It’s an open fact that they always transmit information about the preceding text and suggest a double decoding. On the one hand, the recipient decodes this information, on the other – accepts this as a sort of hidden, “secret” sense.


1990 ◽  
Vol 55 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Zdeněk Friedl ◽  
Stanislav Böhm

The relative enthalpies of proton transfer δ ΔH0and homolytic bond strengths δDH0(B-H+) were calculated by the MNDO method for the sp and ap conformers of 4-flurobutylamine. The data obtained, along with the experimental gas phase basicities, are compared with the values predicted by the electrostatic theory. It is shown that the substituent polar effects FD on the basicities of amines are predominantly due to interactions in their protonated forms (X-B-H+) and/or radical-cations (X-B+.), those in the neutral species (X-B) playing a minor part. A contribution, which is considerably more significant in the sp conformer than in the ap conformer, arises probably also from substituent effects on the homolytic bond strength DH0(B-H+.


Author(s):  
Judith Fuchs

This chapter describes the taxonomy of Phoronida, a small group of exclusively marine invertebrates found in most of the world's oceans from the intertidal zone to about 400 metres depth. Phoronids are meroplanktonic with a planktonic larval stage usually less than 2 mm in length and a benthic adult whose length ranges from a few cm up to 50 cm. The chapter covers their life cycle, ecology, and general morphology. It includes a section that indicates the systematic placement of the taxon described within the tree of life, and lists the key marine representative illustrated in the chapter (usually to genus or family level). This section also provides information on the taxonomic authorities responsible for the classification adopted, recent changes which might have occurred, and lists relevant taxonomic sources.


Buildings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 215
Author(s):  
Bojana Petrović ◽  
Xingxing Zhang ◽  
Ola Eriksson ◽  
Marita Wallhagen

The objective of this paper was to explore long-term costs for a single-family house in Sweden during its entire lifetime. In order to estimate the total costs, considering construction, replacement, operation, and end-of-life costs over the long term, the life cycle cost (LCC) method was applied. Different cost solutions were analysed including various economic parameters in a sensitivity analysis. Economic parameters used in the analysis include various nominal discount rates (7%, 5%, and 3%), an inflation rate of 2%, and energy escalation rates (2–6%). The study includes two lifespans (100 and 50 years). The discounting scheme was used in the calculations. Additionally, carbon-dioxide equivalent (CO2e) emissions were considered and systematically analysed with costs. Findings show that when the discount rate is decreased from 7% to 3%, the total costs are increased significantly, by 44% for a 100-year lifespan, while for a 50 years lifespan the total costs show a minor increase by 18%. The construction costs represent a major part of total LCC, with labor costs making up half of them. Considering costs and emissions together, a full correlation was not found, while a partial relationship was investigated. Results can be useful for decision-makers in the building sector.


1953 ◽  
Vol 4 (4) ◽  
pp. 415 ◽  
Author(s):  
MW Jeffery

Investigation into the possible sources of primary infection by the fungus Ventruia inaequalis (Cooke) Wint. in spring has been carried out. The results present new information on the life cycle of the pathogen under South Australian conditions. Sources of primary infection, such 'as lesions on one-year-old wood or overwintering superficial conidia on the trees, do not appear important. Bud-scale infection of dormant buds has been shown, and its relative importance is discussed. Ascospores are the most important source of primary infection. Their period of discharge extends to a later date than previously reported for South Australia and is considered in relation to leader shoot and late summer spot infection.


Open Physics ◽  
2003 ◽  
Vol 1 (4) ◽  
Author(s):  
A. Pavlov ◽  
Y. Pavlova

AbstractThe formation of Saturn and its disk is simulated using a new N-body self-gravitational model. It is demonstrated that the formation of the disk and the planet is the result of gravitational contraction of a slowly rotated particle cloud that have a shape of slightly deformed sphere. The sphere was flattened by a coefficient of 0.8 along the axis of rotation. During the gravitational contraction, the major part of the cloud transformed into a planet and a minor part transformed into a disk. The thin structured disk is a result of the electromagnetic interaction in which the magnetic forces acting on charged particles of the cloud originate in the core of the planet. The simulation program gives such parameters of Saturn as the escape velocity of about 35 km/s at the surface, density, rotational velocities of the rings and temperature distribution.


2005 ◽  
Vol 37 (5) ◽  
pp. 373-382 ◽  
Author(s):  
William B. SANDERS

The utility of plastic cover slips as a substratum for in situ study of lichen developmental stages is further explored in a neotropical foliicolous lichen community and in a European temperate corticolous community. Twenty-one months after placement in the tropical forest, the cover slips bore foliicolous lichen thalli with several species producing characteristic ascocarps and ascospores, indicating the suitability of the substratum for completion of the life cycle of these lichens. On cover slips placed within the temperate corticolous community, lichen propagules anchored to the substratum with relatively short attachment hyphae but did not develop further within the one year observation period. Intimately intermixed microbial communities of short-celled, mainly pigmented fungi and chlorophyte algae developed upon the transparent substratum. Among the algae, Trebouxia cells, often in groups showing cell division and without associated lichenizing hyphae, were commonly observed. The potential significance of the free-living populations in the life cycle of Trebouxia and in those of Trebouxia-associated lichen fungi is discussed.


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