scholarly journals Veteran trees are a source of natural enemies

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ross Wetherbee ◽  
Tone Birkemoe ◽  
Anne Sverdrup-Thygeson
Keyword(s):  
Experimental Design ◽  
Natural Enemies ◽  
Economic Damage ◽  
Essential Step ◽  
Potential Source ◽  
Veteran Trees ◽  
Sustainable System ◽  
Southern Norway ◽  
Invertebrate Pests

Abstract Predation of invertebrate pest by natural enemies is a critical contribution of nature to people, because invertebrate pests cause a vast amount of economic damage and pesticides use has many long-term costs. Veteran trees are keystone structures and hotspots for biodiversity, and are a potential source of natural enemies. To explore this, we used a balanced experimental design where we measured predatory beetle diversity and attack marks on three colors of artificial caterpillars placed around 20 veteran oaks and 20 nearby young oaks, in Southern Norway. We predicted that around the veteran oaks there would be a greater diversity of predatory beetles and more invertebrate attacks on artificial caterpillars. Sampling for predatory beetles was conducted in summer 2017 and 2018, and invertebrate attacks were measured in 2018. We found support for the predictions: diversity of predatory beetles was higher around veteran trees and there were more arthropod attack marks on artificial caterpillars placed around veteran trees. Our results indicated that veteran trees are a source of natural enemies. Valuing and protecting veteran trees and their communities is an essential step towards a more sustainable system of management that has the possibility of promoting both the wellbeing of people and biodiversity.

Investigations on the filtration of natural aquatic suspensions supported by dosing small amounts of Fe(III)-salts (βFe ≤ 0.1 mg.L-1): mode of action and basic design criteria

2002 ◽  
Vol 2 (2) ◽  
pp. 91-98
Author(s):  
R. Winzenbacher ◽  
R. Schick ◽  
H.-H. Stabel ◽  
M. Jekel
Keyword(s):  
Large Scale ◽  
Suspended Solids ◽  
Iron Hydroxides ◽  
Essential Step ◽  
Iron Salts ◽  
Alkaline Earths ◽  
Co Precipitation ◽  
Solid Liquid ◽  
Solid Liquid Separation

Improved removal of particles during the treatment of natural aquatic suspensions has been achieved by pre-ozonation and the addition of small quantities of iron salts (βFe ≤ 0.1 mg.L-1; “Fe(III)-assisted filtration”) followed by rapid filtration. As shown by investigations on a large-scale installation at Lake Constance Water Supply, this procedure reliably reduces suspended solids by at least 2-3 powers of ten in long-term use. However, the high efficacy of Fe(III)-assisted filtration cannot be explained on the basis of known coagulation mechanisms (like adsorption-charge neutralization, co-precipitation). Instead, the essential step was found to be the conditioning of the filter medium by coating it with colloids containing Fe(OH)3, and this “Fe coating” process occurs only in the presence of alkaline earths (especially Ca2+). According to further experiments, the enhanced solid-liquid separation was ultimately traced to chemical interactions such as the formation of calcium-organic association structures between the iron hydroxides and other solids. For design of Fe(III)-assisted filtration steps, finally, a βCa/DOC ratio above 40 mg.mg-1 and pre-oxidation with ozone dosages not exceeding 2 mg O3/mg DOC was recommended.

The influence of hardwood content on balsam fir defoliation by spruce budworm

1996 ◽  
Vol 26 (9) ◽  
pp. 1620-1628 ◽  
Author(s):  
Qiong Su ◽  
Ted D. Needham ◽  
David A. MacLean
Keyword(s):  
New Brunswick ◽  
Natural Enemies ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Generalized Model ◽  
Stand Management ◽  
Working Hypothesis ◽  
Model Combining

Changing stand composition by increasing hardwood content has been suggested as a long-term method for reducing susceptibility and vulnerability of balsam fir (Abiesbalsamea (L.) Mill.) to spruce budworm (Choristoneurafumiferana (Clem.)). Twenty-five mixed balsam fir–hardwood stands were selected in northern New Brunswick, with five stands in each 20% hardwood class (0–20, 21–40%, etc.). Defoliation each year from 1989 to 1993 was significantly (p < 0.0001) related to hardwood content, with r2 ranging from 0.57 to 0.81. As hardwood content increased, defoliation of balsam fir decreased. From 1989 to 1992, the years of moderate to severe defoliation, balsam fir stands with <40% hardwoods sustained 58–71% defoliation, on average, versus 12–15% defoliation in stands with >80% hardwood. A generalized model combining hardwood content and the estimated defoliation in pure softwood stands in a given year explained 77% of the variation in defoliation over stands and years. This study indicated that mixed balsam fir–hardwood stand management, with hardwood content >40%, could substantially reduce losses during spruce budworm outbreaks. Further research is warranted to elucidate the mechanism involved, but our working hypothesis is that greater hardwood content increased the diversity or populations of natural enemies such as birds and parasitoids.

Will Strategy Prevail over Economics? An Analysis of Charanka Solar Park in Gujarat

2016 ◽  
Vol 5 (2) ◽  
pp. 162-167
Author(s):  
Saif Siddiqui ◽  
Sumaira Jan
Keyword(s):  
Solar Energy ◽  
Solar Power ◽  
Power Production ◽  
Energy Crisis ◽  
Energy Sources ◽  
Potential Source ◽  
The World ◽  
Made In

The Charanka Solar Park, one of the world’s largest multi-developer and multi-beneficiary solar parks, is the hub of solar power production in India. It contributes about 6 per cent to the total solar power production in the country. Although solar power is more expensive than the traditional power in the country, its sheen is still not high to make it a potential source to eliminate energy crisis not just in India but all across the world. Researchers are continuously pushing their envelope to explore as to why solar energy should be adopted over traditional energy sources irrespective of the fact that it is more expensive. The war between its financial and strategic viability is going on. Efforts are being made in the direction of reducing its costs and making it as a financially viable and strategically active option. This case is an attempt in the same direction. We are using Charanka Solar Park as a base to explore if there is any future for such projects in the country. There are projects which are no doubt operational but their long-term viability is truly questionable.

Developing an Adaptive Management approach to prescribed burning: a long-term heathland conservation experiment in north-west Italy

2009 ◽  
Vol 18 (6) ◽  
pp. 727 ◽  
Author(s):  
Davide Ascoli ◽  
Rachele Beghin ◽  
Riccardo Ceccato ◽  
Alessandra Gorlier ◽  
Giampiero Lombardi ◽  
...  
Keyword(s):  
Experimental Design ◽  
Adaptive Management ◽  
Prescribed Burning ◽  
Fire Regime ◽  
Management Approach ◽  
Detailed Measurement ◽  
Research Issues ◽  
North West ◽  
Heathland Management

Calluna vulgaris-dominated heathlands are globally important habitats and extremely scarce outside of north-west Europe. Rotational fire, grazing and cutting by local farmers were dominant features of past heathland management throughout Europe but have been abandoned, altering the historical fire regime and habitat structure. We briefly review research on Calluna heathland conservation management and provide the background and methodology for a long-term research project that will be used to define prescribed fire regimes in combination with grazing and cutting, for management of Calluna heathlands in north-west Italy. We outline the ecological and research issues that drive the fire experiment, making explicit the experimental design and the hypotheses that will be tested. We demonstrate how Adaptive Management can be used to inform decisions about the nature of fire prescriptions where little formal knowledge exists. Experimental plots ranging from 600 to 2500 m2 are treated according to one of eight alternative treatments (various combinations of fire, grazing and cutting), each replicated four times. To date, all treatments have been applied for 4 years, from 2005 to 2008, and a continuation is planned. Detailed measurement of fire characteristics is made to help interpret ecological responses at a microplot scale. The results of the experiment will be fed back into the experimental design and used to inform heathland management practice in north-west Italy.

scholarly journals Parasites of beetles which are pests of grain and products of its processing

2018 ◽  
Vol 25 (4) ◽  
Author(s):  
V. O. Martynov
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Callosobruchus Maculatus ◽  
Ecological Condition ◽  
Rhyzopertha Dominica ◽  
Economic Damage ◽  
Crop Pests ◽  
Main Crop ◽  
Anisopteromalus Calandrae ◽  
Favorable Conditions

Crop pests are the cause of economic damage in many developing countries, including Ukraine, where annual loss of crop harvest on average equals 6 million tons, valued at 840 million dollars. Pests consume grain, causing its pollution and creating favorable conditions for development of mold, which significantly decreases the food and seeding properties of grain and products of its processing. This article presents basic data on biological control and its advantages, demonstrates the variety of natural enemies of the pest beetles, which are used in biological control, analyses studies of the biological control of main crop pests and products of its processing belonging to the families Curculionidae and Tenebrionidae, and also the role of competition in  biological control. The analysis of studies on the effectiveness of different natural enemies of the main crop pest-beetles shows that the most studied parasites are Sitophilus granarius, S. zeamais, Tribolium confusum, T. castaneum, Oryzaephilus surinamensis, Rhyzopertha dominica, Acanthoscelides obtectus and Callosobruchus maculatus. Natural enemies of the rest of the species are poorly studied, and there is no data on Caulophilus latinasus, Tenebroides mauritanicus, Dermestes lardarius, Ptinus fur and Bruchidius incarnatus. The most commonly used natural enemies are Xylocoris flavipes, Anisopteromalus calandrae, the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana, and also nematodes of the Steinernema and Heterorhabditis genera. Despite the broad spectrum of natural enemies of the main pests of the grain supply, it is necessary to further study the parasites of every species of beetle which causes economic damage. Using biological control is the most promising method against pests of crops and products of its processing, which meets the current requirements to the sanitary-ecological condition of agricultural production.

scholarly journals Risk Based Improvement Performance Strategy for Operation and Maintenance Activities of River and River Infrastructure (BBWS Ciliwung-Cisadane Authority)

2021 ◽  
Vol 1 ◽  
Author(s):  
Isni Septima Anindhita
Keyword(s):  
Flood Control ◽  
Public Works ◽  
Short Term ◽  
Risk Response ◽  
Operation And Maintenance ◽  
Recommendations For Action ◽  
Maintenance Activities ◽  
Sustainable System ◽  
Term Maintenance

The Ministry of Public Works and Public Housing (PUPR) has the duty and responsibility to carry out effective and efficient river operation activities and river infrastructure including overcoming floods during the rainy season, but these activities are deemed necessary for improvement in planning procedures. To realize this goal, it is necessary to manage risks that can reduce river performance and river infrastructure as flood control. With risk management in this activity, it is possible to apply the sequence of risks that occur which are then used as recommendations for action (risk response) and risk-based development strategies to improve river performance and river infrastructure to control floods through operation and maintenance activities to build a functional and sustainable system. Suitable for long-term planning and short-term maintenance needs.

scholarly journals Conservation of Non-Pest Whiteflies and Natural Enemies of the Cabbage Whitefly Aleyrodes proletella on Perennial Plants for Use in Non-Crop Habitats

Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 774
Author(s):  
Sebastian Laurenz ◽  
Rainer Meyhöfer
Keyword(s):  
Natural Enemies ◽  
Control Strategies ◽  
Conservation Biological Control ◽  
Future Research ◽  
Economic Damage ◽  
Naturally Occurring ◽  
Brassica Crops ◽  
Aleyrodes Proletella ◽  
Local Abundance ◽  
Geum Urbanum

Aleyrodes proletella causes severe economic damage to several Brassica crops. Its naturally occurring enemies often immigrate late in the season or appear in low numbers on cabbage. This field study aims to permanently increase the local abundance of A. proletella’s natural enemies by providing the non-pest whitefly Aleyrodes lonicerae as an alternative and overwintering host/prey. Therefore, the population dynamics of natural enemies on different perennial herbaceous plants pre-infested with A. lonicerae were determined at two field locations over two winter periods. Most A. lonicerae colonized (on average 166.22 puparia per m²) and overwintered (342.19 adults per m²) on wood avens Geum urbanum. Furthermore, the abundance of A. proletella main parasitoid Encarsia tricolor (28.50 parasitized puparia per m²) and spiders (12.13 per m²) was 3–74 times and 3–14 times higher, respectively, on G. urbanum compared to the other experimental plants. Conclusively, G. urbanum pre-infested with A. lonicerae permanently promoted natural enemies of A. proletella by serving as shelter, reproduction, and overwintering habitat. A potential implementation of G. urbanum in conservation biological control strategies (e.g., tailored flower strips, hedgerows) against A. proletella are discussed and suggestions for future research are given.

scholarly journals Long-term seasonal fluctuations of lepidopteran cereal stemborers and their natural enemies on maize and wild host plants in southern Benin

2009 ◽  
Vol 16 (4) ◽  
pp. 329-341 ◽  
Author(s):  
Saka Gounou ◽  
Nanqing Jiang ◽  
Fritz Schulthess
Keyword(s):  
Natural Enemies ◽  
Host Plants ◽  
Seasonal Fluctuations ◽  
Wild Host ◽  
Southern Benin

scholarly journals Conserving carnivorous arthropods: an example from early-season cranberry (Ericaceae) flooding

2018 ◽  
Vol 150 (2) ◽  
pp. 265-273
Author(s):  
J. van Zoeren ◽  
C. Guédot ◽  
S.A. Steffan
Keyword(s):  
Biological Control ◽  
Pest Management ◽  
Natural Enemies ◽  
Control Strategies ◽  
Cultural Control ◽  
Generalist Predators ◽  
Early Season ◽  
Insecticide Application ◽  
Insecticide Spray

AbstractBiological control plays an important role in many integrated pest management programmes, but can be disrupted by other control strategies, including chemical and cultural controls. In commercial cranberry (Vaccinium macrocarpon Aiton; Ericaceae) production, a spring flood can replace an insecticide application, providing an opportunity to study the compatibility of the flood (a cultural control) with biological control. We suspect that chemical controls will tend to reduce the number of natural enemies, while the flood, through removal of detritus and detritivores, may cause generalist predators to prey-switch to consume proportionally more pest individuals. We measured the abundance of herbivores (Lepidoptera), detritivores, Arachnida, and parasitoids (Hymenoptera) every week for six weeks in Wisconsin (United States of America) cranberry beds following either an insecticide spray or a cultural control flood. We found that detritivore populations rapidly declined in both flood and spray treatments; conversely, carnivore populations (spiders and parasitoids) were more abundant in the flooded beds than in sprayed beds. Populations of key cranberry pests were similar between flooded and sprayed beds. Our results showed that early-season flooding preserved more natural enemies than an insecticide application. This increase in natural enemy abundance after the flood may allow for greater continuity in herbivore suppression, potentially providing a basis for long-term cranberry pest management.

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