scholarly journals Bioecological peculiarities and economic significance of large fruit bark beetle (Scolytus mali Bechstein, 1805) and fig bark beetle (Hypoborus ficus Erichson, 1836) in the southern slopes of the Great Caucasus (Azerbaijan)

2021 ◽  
Vol 15 (1) ◽  
pp. 61-66
Author(s):  
K. B. Isayeva ◽  
Keyword(s):  
Bark Beetle ◽  
Bark Beetles ◽  
Fruit Trees ◽  
Study Region ◽  
Vegetative Organs ◽  
Greater Caucasus ◽  
Economic Significance ◽  
Host Trees ◽  
Large Numbers

Background. Bark beetles (Coleoptera, Curculionidae, Scolytinae) are major pests of wood-fruit trees, and infestations often accelerate tree death. Bark beetles are insects that are closely related to their host trees. According to the type of feeding they belong to xylophages [7]. They prefer weakened, sick or damaged trees. Thus, bark beeteles can more easily penetrate into trees affected by various natural phenomena (wind, storm, rain) or primary pests. They are hardly ever found in rotting trees. The research was carried out on the southern slopes of the Great Caucasus during the period 2013–2016. The great difference in the altitude in the study area results in a variety of natural conditions. This, in turn, leads to the richess of fauna and flora of the area. Thus, valuable fruit trees grow both in the forests and fruit farms of the study region. However, large numbers of fruit trees are attacked by bark beetles every year, which negatively affects the numbers and the quality of trees. Untimely processing of the trees leads to their drying and destruction. According to modern systematics, bark beetles belong to the Scolytinae (Latreille, 1804) subfamily of the Curculionidae (Latreille, 1802) family. There are about 6,000 species of bark beetles from 28 triba and 230 genera in the world [8]. These insects also cause serious damage in countries neighboring of Azerbaijan [1, 2, 9, 11 ]. Despite the fact that bark beetles are of great agricultural importance, they are not sufficiently studied in Azerbaijan. Materials and Methods.The material for research was collected and treated according to common entomological methods. The vegetative organs of various trees were cut and dissected to detect adult beetles, eggs and larvae of bark beetles. Identification of bark beetles was carried out according to keys. MBS-9 microscope was used to determine the morphological features of beetles. Results. As a results of the research, we analyzed 241 samples (237 adults and 4 pupae) of bark beetles collected in 7 districts of the southern slopes of the Greater Caucasus, of which 54 specimens belonged to Scolytus mali and 187 to Hypoborus ficus. Conclusion. Out of 30 species of bark beetles detected on the southern slopes of the Greater Caucasus, 7 ones (Scolytus mali Bechst., S. amygdali Guer., S. fasciatus Rtt., S. rugulosus Ratz., Hypoborus ficus Er., Xyleborus dispar F., X. saxeseni Ratz.) were determined as fruit trees pests. Two of them (Scolytus mali and Hypoborus ficus) are widely distributed in the area and cause serious damage to fruit trees.

scholarly journals Influence of selected factors on bark beetle outbreak dynamics in the Western Carpathians

2015 ◽  
Vol 61 (3) ◽  
pp. 149-156 ◽  
Author(s):  
Jozef Vakula ◽  
Milan Zúbrik ◽  
Juraj Galko ◽  
Andrej Gubka ◽  
Andrej Kunca ◽  
...  
Keyword(s):  
Bark Beetle ◽  
Bark Beetles ◽  
Western Carpathians ◽  
Average Temperature ◽  
Growing Seasons ◽  
Precipitation Total ◽  
Spruce Stands ◽  
High Age ◽  
Artificial Origin

Abstract In the period from 1992 to 2013, more than 3.8 million m3 of spruce wood from an area of 55 thousand ha of forests in the Kysuce region (Western Carpathians) was affected by bark beetles. This region has had the highest volume of salvage fellings in Slovakia. While before 1991, bark-beetle outbreak usually occurred after snow and wind disturbances, since 1992 they have occurred in the years with extremely warm and dry growing seasons and the years following them. These years were also characterised by high volumes of wood affected by honey fungus (Armillaria spp.), which only rarely took part in the calamities before 1992. Extreme deterioration of the situation occurred after 2003. In fragmented and sparse stands, the volume of wood damaged by wind increased. Artificial origin of spruce stands, their high occurrence, high age and even-agedness are likely pre-disposing factors of spruce forest decline. Bark beetles have become the most important factor of spruce decline. The most important factors driving the bark beetle attack on forest stands in the period 1973–2013 were the amount of unprocessed wood in the previous year; the amount of wood affected by honey fungus, precipitation total, and average temperature in the current growing season. Another important factor that complicated the situation was also the inferior quality of forest management.

How to manage windthrows in Central Europe to prevent bark beetle outbreaks?

2020 ◽  
Author(s):  
Laura Dobor ◽  
Tomáš Hlásny ◽  
Werner Rammer ◽  
Soňa Zimová ◽  
Rupert Seidl
Keyword(s):  
Central Europe ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Forest Landscape ◽  
Conservation Areas ◽  
Management Objectives ◽  
Host Trees ◽  
Dead Trees ◽  
Amplifying Effect ◽  
Disturbance Model

<p>Bark beetle (Ips typographus) epidemics in Europe are typically triggered by excessive availability of freshly dead trees and trees with compromised defense, which often occur after windstorms or droughts. Subsequently, enlarged beetle populations migrate to the surrounding forests, which were not affected by the primary disturbance. Removal of windfelled trees (salvage or sanitation logging) is therefore a frequent management response to prevent the build-up of bark beetle populations. Yet, the effectivity of the removal remains poorly understood, particularly when the outbreaks are amplified by faster beetle development cycles and reduced tree defense under climate change conditions.</p><p>Moreover, diverse ownership, management objectives and limited resources often restrict salvaging operations, and the final effect on bark beetle populations is thus even less clear. To better understand the interplay between climate, management, bark beetle populations, and host trees, we use the process-based forest landscape and disturbance model iLand. We studied differences between the removal of windfelled trees applied evenly across the landscape, focused on the vicinity of roads (scenario of limited logging resources) and concentrated in a contiguous block (scenario of spatially diversified management objectives) on a 16 050 ha forest landscape in Central Europe. We found that the removal of >80% of all windfelled trees is required to substantially reduce bark beetle disturbances. Focusing on the vicinity of roads created a “fire break effect” on bark beetle spread, and was moderately efficient in reducing landscape-scale bark beetle disturbance. Block treatments substantially reduced outbreaks in treated areas. Leaving parts of the landscape untreated (e.g., conservation areas) had no significant amplifying effect on outbreaks in managed areas. Our research suggests that the management of interacting disturbances from wind and bark beetles requires much more complex considerations than are currently practiced.</p>

scholarly journals Spatial distribution of four spruce bark beetles in north-western Slovakia

2008 ◽  
Vol 53 (Special Issue) ◽  
pp. 45-52 ◽  
Author(s):  
M. Turčáni ◽  
T. Hlásny
Keyword(s):  
Spatial Distribution ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Control Measures ◽  
Beetle Species ◽  
Study Region ◽  
The North ◽  
Spruce Bark ◽  
Infestation Density ◽  
Study Species

Infestation density of four the most common spruce bark beetle species was estimated on 15 study sites (10 trees per site) in the Kysuce model region in 2006. Five half-metre long sections of the stem were selected and dissected at the base of the stem; midway between the base of the stem and the base of the crown; just below the base of the crown; in the middle of the crown; and in the upper part of the crown. The infestation density of bark beetles, expressed as the number of mating chambers per dm<sup>2</sup>, was determined. Ordinary kriging was then used to produce smooth maps and visualize spatial distribution of study species. Maps with isolines indicating high infestation were produced for study species (<I>I. Typographus</I> over 0.38; (<I>I. amitinu</I>s over 0.15; (<I>I. duplicatus</I> over 0.11; and <I>P. chalcographus</I> over 0.415 nuptial chambers per dm<sup>2</sup>). <I>Ips typographus</I> L. remained dominant species on majority of sites having high intensity of infestation. Lower altitudes in the south-eastern part of the region were often infested by <I>I. duplicatus</I> Sahlberg and also by <I>I. typographu</I> and <I>Pityogenes chalcographus</I> L. Higher elevations in the north-eastern part of territory in the vicinity of border with Poland were heavily infested by <I>I. amitinus</I> Eichhoff (often with <I>I. typographus). P. chalcographus</I> was abundant on majority of territory – mainly in southern half of area. However locally, it was found in extremely high abundance. The results suggest the need for control measures set up jointly against the most abundant bark beetle species in study region.

Scoundrels or Stars? Theory and Evidence on the Quality of Workers in Online Labor Markets

2016 ◽  
Vol 92 (1) ◽  
pp. 93-114 ◽  
Author(s):  
Anne M. Farrell ◽  
Jonathan H. Grenier ◽  
Justin Leiby
Keyword(s):  
Labor Markets ◽  
Data Availability ◽  
Accounting Research ◽  
Research Participants ◽  
Large Numbers ◽  
Research Designs ◽  
Online Labor Markets ◽  
Online Labor ◽  
Low Pay

ABSTRACT Online labor markets allow rapid recruitment of large numbers of workers for very low pay. Although online workers are often used as research participants, there is little evidence that they are motivated to make costly choices to forgo wealth or leisure that are often central to addressing accounting research questions. Thus, we investigate the validity of using online workers as a proxy for non-experts when accounting research designs use more demanding tasks than these workers typically complete. Three experiments examine the costly choices of online workers relative to student research participants. We find that online workers are at least as willing as students to make costly choices, even at significantly lower wages. We also find that online workers are sensitive to performance-based wages, which are just as effective in inducing high effort as high fixed wages. We discuss implications of our results for conducting accounting research with online workers. Data Availability: Contact the authors.

Animal Models and Alternatives in the Quality Control of Vaccines: Are In Vitro Methods or In Vivo Methods the Scientific Equivalent of the Emperor's New Clothes?

1995 ◽  
Vol 23 (1) ◽  
pp. 61-73
Author(s):  
Coenraad Hendriksen ◽  
Johan van der Gun
Keyword(s):  
Quality Control ◽  
Test Methods ◽  
In Vitro Test ◽  
Large Numbers ◽  
Alternative Approach ◽  
Inactivated Vaccines ◽  
Vitro Test

In the quality control of vaccine batches, the potency testing of inactivated vaccines is one of the areas requiring very large numbers of animals, which usually suffer significant distress as a result of the experimental procedures employed. This article deals with the potency testing of diphtheria and tetanus toxoids, two vaccines which are used extensively throughout the world. The relevance of the potency test prescribed by the European Pharmacopoeia monographs is questioned. The validity of the potency test as a model for the human response, the ability of the test to be standardised, and the relevance of the test in relation to the quality of the product are discussed. It is concluded that the potency test has only limited predictive value for the antitoxin responses to be expected in recipients of these toxoids. An alternative approach for estimating the potency of toxoid batches is discussed, in which a distinction is made between estimation of the immunogenic potency of the first few batches obtained from a seed lot and monitoring the consistency of the quality of subsequent batches. The use of animals is limited to the first few batches. Monitoring the consistency of the quality of subsequent batches is based on in vitro test methods. Factors which hamper the introduction and acceptance of the alternative approach are considered. Finally, proposals are made for replacement, reduction and/or refinement (the Three Rs) in the use of animals in the routine potency testing of toxoids.

scholarly journals Assessment and distribution of water quality of Pandoh river basin (PRB), Himachal Pradesh, North India

2021 ◽  
Vol 11 (8) ◽  
Author(s):  
C. Prakasam ◽  
R. Saravanan ◽  
M. K. Sharma ◽  
Varinder S. Kanwar
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
River Basin ◽  
Geographical Information ◽  
North India ◽  
Total Hardness ◽  
Drainage Pattern ◽  
Study Region ◽  
Northern India

AbstractAs the surface water in northern India is the main water resource for regional economic and also supply for drinking and irrigation purposes. However, deficiency of water quality leads to serious water pollution in the Pandoh river basin (PRB). Therefore, the main objective of the present study is to evaluate the quality of surface water. With this objective, surface water samples were collected from the PRB of northern India, and analyzed for pH, EC, turbidity, alkalinity, total dissolved solids, and total hardness. Moreover, geographical information system (GIS) tools were used to prepare the geology, drainage pattern, and location maps of the study region. Surface water quality observed from the PRB has an alkaline nature with a moderately hard type. Further studies are encouraged to better understand the water quality in northern India.

scholarly journals Drivers of Spruce Bark Beetle (Ips typographus) Infestations on Downed Trees after Severe Windthrow

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1290
Author(s):  
Branislav Hroššo ◽  
Pavel Mezei ◽  
Mária Potterf ◽  
Andrej Majdák ◽  
Miroslav Blaženec ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Ips Typographus ◽  
Wind Damage ◽  
Stem Length ◽  
Local Conditions ◽  
Spruce Bark Beetle ◽  
Management Actions ◽  
Spruce Bark

Research Highlights: Bark beetles are important agents of disturbance regimes in temperate forests, and specifically in a connected wind-bark beetle disturbance system. Large-scale windthrows trigger population growth of the European spruce bark beetle (Ips typographus L.) from endemic to epidemic levels, thereby allowing the killing of Norway spruce trees over several consecutive years. Background and Objectives: There is a lack of evidence to differentiate how outbreaks are promoted by the effects of environmental variables versus beetle preferences of trees from endemic to outbreak. However, little is known about how individual downed-tree characteristics and local conditions such as tree orientation and solar radiation affect beetle colonization of downed trees. Materials and Methods: To answer this question, we investigated the infestation rates and determined tree death categories (uprooted, broken, and stump) in wind-damaged areas in Western Tatra Mts. in Carpathians (Slovakia) from 2014–2016, following a windthrow in May 2014. In total, we investigated 225 trees over eight transects. For every tree, we measured its morphological (tree height, crown characteristics), environmental (solar radiation, terrain conditions, trunk zenith), temporal (time since wind damage), and beetle infestation (presence, location of attack, bark desiccation) parameters. We applied Generalized Additive Mixed Models (GAMM) to unravel the main drivers of I. typographus infestations. Results: Over the first year, beetles preferred to attack broken trees and sun-exposed trunk sides over uprooted trees; the infestation on shaded sides started in the second year along with the infestation of uprooted trees with lower desiccation rates. We found that time since wind damage, stem length, and incident solar radiation increased the probability of beetle infestation, although both solar radiation and trunk zenith exhibited nonlinear variability. Our novel variable trunk zenith appeared to be an important predictor of bark beetle infestation probability. We conclude that trunk zenith as a simple measure defining the position of downed trees over the terrain can anticipate beetle infestation. Conclusions: Our findings contribute to understanding of the bark beetle’s preferences to colonize windthrown trees in the initial years after the primary wind damage. Further, our findings can help to identify trees that are most susceptible to beetle infestation and to prioritize management actions to control beetle population while maintaining biodiversity.

INFESTATION OF CERATOCYSTIS WAGENERI-INFECTED PONDEROSA PINES BY BARK BEETLES (COLEOPTERA: SCOLYTIDAE) IN THE CENTRAL SIERRA NEVADA

1980 ◽  
Vol 112 (7) ◽  
pp. 725-730 ◽  
Author(s):  
D. J. Goheen ◽  
F. W. Cobb
Keyword(s):  
Sierra Nevada ◽  
Bark Beetle ◽  
Ponderosa Pine ◽  
Bark Beetles ◽  
Dendroctonus Brevicomis ◽  
Disease Category ◽  
The Relationship ◽  
Periodic Examination ◽  
Apparently Healthy

AbstractThe relationship between bark beetle infestation of ponderosa pine and severity of infection by Ceratocystis wageneri was investigated by closely monitoring 256 trees (136 apparently healthy, 60 moderately diseased, and 60 severely diseased at initiation of study) for beetle infestation from summer 1972 to fall 1975. Disease ratings were updated by periodic examination, and some trees changed disease category during the study. Ninety trees were infested by Dendroctonus brevicomis, D. ponderosae, or both, five by buprestids alone, and one tree died from effects of the pathogen alone. Sixty-two of the beetle-infested trees were severely diseased at time of infestation, 25 were moderately diseased, and only three were apparently healthy. Thus, the results showed that bark beetles were much more likely to infest infected than healthy trees. Among diseased trees, those with advanced infections were most likely to be infested. There was evidence that buprestids (especially Melanophila spp.) and possibly Ips spp. attacked diseased trees prior to Dendroctonus spp. infestation.

ATTRACTION OF HYLOBIUS PALES (HERBST) (COLEOPTERA: CURCULIONIDAE) TO PHEROMONES OF BARK BEETLES (COLEOPTERA: SCOLYTIDAE)

1990 ◽  
Vol 122 (3) ◽  
pp. 423-427 ◽  
Author(s):  
Thomas W. Phillips
Keyword(s):  
Field Experiment ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Suitable Host ◽  
Male And Female ◽  
Pine Weevil ◽  
Ips Calligraphus ◽  
Hylobius Pales ◽  
Host Resource

AbstractResults of a field experiment indicate that adults of the pine weevil Hylobius pales (Herbst) respond to pheromones of bark beetles. Each sex of H. pales was more attracted to traps baited with the combination of a pine bolt infested with male Ips calligraphus Germar plus the synthetic Dendroctonus Erichson pheromones frontalin and exo-brevicomin, than to traps baited with pine bolts alone. The combined numbers of male and female H. pales caught in traps baited only with Ips calligraphus-infested bolts were significantly greater than numbers caught in traps baited with uninfested control bolts. The attraction of H. pales to bark beetle pheromones may represent a kairomonal response in which weevils exploit semiochemicals from other species that signify a suitable host resource.

Impacts of European spruce bark beetle infestations on Norway spruce BVOC emissions

2021 ◽  
Author(s):  
Erica Jaakkola ◽  
Anna Maria Jönsson ◽  
Per-Ola Olsson ◽  
Maj-Lena Linderson ◽  
Thomas Holst
Keyword(s):  
Climate Change ◽  
Drought Stress ◽  
Norway Spruce ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Atmospheric Environment ◽  
Strong Increase ◽  
Healthy Tree ◽  
Spruce Bark Beetle ◽  
Spruce Bark

&lt;p&gt;Tree killing by spruce bark beetles (&lt;em&gt;Ips typographus&lt;/em&gt;) is one of the main disturbances to Norway spruce (&lt;em&gt;Picea abies&lt;/em&gt;) forests in Europe and the risk of outbreaks is amplified by climate change with effects such as increased risk of storm felling, tree drought stress and an additional generation of spruce bark beetles per year&lt;sup&gt;[1]&lt;/sup&gt;. The warm and dry&amp;#160;summer of&amp;#160;2018 triggered large outbreaks in Sweden, the increased outbreaks are still ongoing and affected&amp;#160;about 8 million m&lt;sup&gt;3&lt;/sup&gt;&amp;#160;forest&amp;#160;in 2020&lt;sup&gt;[2]&lt;/sup&gt;. This is the so&amp;#160;far highest record of trees killed by the spruce bark beetle in a single year in Sweden&lt;sup&gt;[2]&lt;/sup&gt;. In&amp;#160;1990-2010,&amp;#160;the spruce bark beetle killed on&amp;#160;average&amp;#160;150 000 m&lt;sup&gt;3&lt;/sup&gt;&amp;#160;forest per year in southern Sweden&lt;sup&gt;[3]&lt;/sup&gt;. Bark beetles normally seek and attack Norway spruces with lowered defense, i.e. trees that are wind-felled or experience prolonged drought stress&lt;sup&gt;[4]&lt;/sup&gt;. However, as the number of bark beetle outbreaks increase, the risk of attacks on healthy trees also increase&lt;sup&gt;[5]&lt;/sup&gt;. This causes a higher threat to forest industry, and lowers the possibilities to mitigate climate change in terms of potential decreases in carbon uptake if the forests die&lt;sup&gt;[4,5]&lt;/sup&gt;. Norway spruce trees normally defend themselves by drenching the beetles in resin&lt;sup&gt;[6]&lt;/sup&gt;. The resin in turn contains different biogenic volatile organic compounds (BVOCs), which can vary if the spruce is attacked by bark beetles or not&lt;sup&gt; [4,6]&lt;/sup&gt;. The most abundant group of terpenoids (isoprene, monoterpenes and sesquiterpenes), is most commonly emitted from conifers, such as Norway spruce&lt;sup&gt;[7,8]&lt;/sup&gt;. The aim of this study was to enable a better understanding of the direct defense mechanisms of spruce trees by&amp;#160;quantifying BVOC emissions and its composition&amp;#160;from individual&amp;#160;trees under attack&lt;/p&gt;&lt;p&gt;To analyze the bark beetles&amp;#8217; impact on Norway spruce trees a method was developed using tree trunk chambers and adsorbent tubes. This enables direct measurements of the production of BVOCs from individual trees. Three different sites in Sweden, with different environmental conditions were used for the study and samples were collected throughout the growing season of 2019. After sampling, the tubes were analyzed in a lab using automated thermal desorption coupled to a gas chromatograph and a mass spectrometer to identify BVOC species and their quantity.&lt;/p&gt;&lt;p&gt;The preliminary results show a strong increase in BVOC emissions from a healthy tree that became infested during the data collection. The finalized results expect to enable better understanding of how spruce trees are affected by insect stress from bark beetles, and if bark beetle infestation will potentially result in increased carbon emission in the form of BVOCs.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;References&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;[1] J&amp;#246;nsson et al. (2012). Agricultural and Forest Meteorology 166: 188&amp;#8211;200&lt;br&gt;[2] Skogsstyrelsen, (2020). https://via.tt.se/pressmeddelande/miljontals-granar-dodades-av-granbarkborren-2020?publisherId=415163&amp;releaseId=3288473&lt;br&gt;[3] Marini et al. (2017). Ecography, 40(12), 1426&amp;#8211;1435.&lt;br&gt;[4] Raffa (1991). Photochemical induction by herbivores. pp. 245-276&lt;strong&gt;&lt;br&gt;&lt;/strong&gt;[5] Seidl, et al. (2014). Nature Climate Change,&amp;#160;4(9), 806-810. &lt;br&gt;[6] Ghimire, et al. (2016).&amp;#160;Atmospheric Environment,&amp;#160;126, 145-152.&lt;br&gt;[7] Niinemets, U. and Monson, R. (2013). ISBN 978-94-007-6606-8&lt;br&gt;[8] Kesselmeier, J. and Staudt, M. (1999). Journal of Atmospheric Chemistry, 33(1), pp.23-88&lt;/p&gt;

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