EFFECTIVENESS OF MALAISE TRAPS IN COLLECTING HYMENOPTERA: THE INFLUENCE OF TRAP DESIGN, MESH SIZE, AND LOCATION

1988 ◽  
Vol 120 (8-9) ◽  
pp. 787-796 ◽  
Author(s):  
D. Christopher Darling ◽  
Laurence Packer
Keyword(s):  
Paired Comparison ◽  
Mesh Size ◽  
Graphical Analysis ◽  
Malaise Trap ◽  
Coarse Mesh ◽  
Trap Design ◽  
Fine Mesh ◽  
Provincial Park ◽  
Pan Traps ◽  
Malaise Traps

AbstractThe influence of various aspects of Malaise trap design on efficiency in collecting various groups of Hymenoptera was compared using commercially available traps. The influence of fine and coarse mesh sizes and the importance of the incorporation of pan traps into the design were evaluated in two sampling periods in an old dune community at Pinery Provincial Park in southern Ontario. Numbers of individuals collected in Malaise trap heads and pan traps were presented for each paired comparison of mesh size (fine and coarse) and location (top and bottom of a hill) for various families of Hymenoptera. A graphical analysis of the normalized catch data for more inclusive groupings, viz. Symphyta, Aculeata, Ichneumonoidea, and microhymenoptera, was presented. The major results of these comparisons were as follows: (1) pan traps were an important component of efficient Malaise traps, especially for Aculeata and microhymenoptera; (2) coarse mesh was more effective in collecting Aculeata; (3) coarse and fine mesh were both effective in collecting Ichneumonoidea; and (4) fine mesh was more effective in collecting microhymenoptera. There was an interaction effect between the type of trap used and groups collected and it was not possible to maximize simultaneously the collection of all groups of Hymenoptera. The use of various mesh types and a trap design that incorporates pan traps was recommended.

scholarly journals TWO-GRID WEAK GALERKIN METHOD FOR SEMILINEAR ELLIPTIC DIFFERENTIAL EQUATIONS

2022 ◽  
Author(s):  
luoping chen ◽  
fanyun wu ◽  
guoyan zeng
Keyword(s):  
Differential Equations ◽  
Galerkin Method ◽  
Mesh Size ◽  
Initial Guess ◽  
Coarse Mesh ◽  
Weak Galerkin ◽  
Fine Mesh ◽  
Semilinear Elliptic ◽  
Elliptic Differential Equations ◽  
Linearized System

In this paper, we investigate a two-grid weak Galerkin method for semilinear elliptic differential equations. The method mainly contains two steps. First, we solve the semi-linear elliptic equation on the coarse mesh with mesh size H, then, we use the coarse mesh solution as a initial guess to linearize the semilinear equation on the fine mesh, i.e., on the fine mesh (with mesh size $h$), we only need to solve a linearized system. Theoretical analysis shows that when the exact solution u has sufficient regularity and $h=H^2$, the two-grid weak Galerkin method achieves the same convergence accuracy as weak Galerkin method. Several examples are given to verify the theoretical results.

scholarly journals Effectiveness of sweep net, yellow pan trap and malaise trap for sampling parasitic hymenoptera on tidal swamp rice

2021 ◽  
Vol 6 (2) ◽  
pp. 62-68
Author(s):  
Zahlul Ikhsan ◽  
Hidrayani Hidrayani ◽  
Yaherwandi Yaherwandi ◽  
Hasmiandy Hamid
Keyword(s):  
Pest Management ◽  
Vital Role ◽  
Malaise Trap ◽  
Parasitoid Species ◽  
Transect Line ◽  
Parasitic Hymenoptera ◽  
Tidal Swamp ◽  
Pan Traps ◽  
Malaise Traps ◽  
Sweep Net

The presence of the parasitic Hymenoptera plays a vital role in pest management for sustainable agriculture. So, it is crucial to know the parasitoid species that exist in an agroecosystem. Sweep Net, Yellow Pan Trap, and Malaise Trap are often used to study the diversity of Hymenoptera parasitic in agroecosystems. This study aims to see the effectiveness of Sweep Net, Yellow Pan Trap, and Malaise Trap in trapping Parasitic Hymenoptera. The study was carried out at four sub-districts, namely are Batang Tuaka, Keritang, Reteh, and Tembilahan Hulu sub-district. The research was carried out by sampling with the transect line method. Sweep net, Yellow pan trap, and Malaise trap have trapped 5,732 individuals of Parasitic Hymenoptera on tidal swamp rice in Indragiri Hilir Regency. The Parasitic Hymenoptera consists of 10 superfamilies, 30 families, and 320 morphospecies. Malaise traps are the best for trapping parasitic Hymenoptera on tidal swamp rice. Malaise traps have been able to trap up to 62% of morphospecies and 81% of the abundance of individual Parasitic Hymenoptera on tidal swamp rice. Yellow pan traps trap 28% of morphospecies and 15% of the abundance of individual Parasitic Hymenoptera. The sweep net can trap 10% of morphospecies and 4% of the abundance of individual Parasitic Hymenoptera.Keywords: Parasitic Hymenoptera; trap; tidal swamp rice.  

Muscidae (Diptera) diversity in Churchill, Canada, between two time periods: evidence for limited changes since the Canadian Northern Insect Survey

2012 ◽  
Vol 144 (1) ◽  
pp. 29-51 ◽  
Author(s):  
Anaïs K. Renaud ◽  
Jade Savage ◽  
Robert E. Roughley
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Malaise Trap ◽  
Collecting Methods ◽  
Insect Survey ◽  
Time Periods ◽  
Trap Catches ◽  
Survey Protocol ◽  
Pan Traps ◽  
Malaise Traps

AbstractA survey of muscid flies from Churchill, Manitoba, Canada, in 2007 yielded 155 species. Some components of species richness and composition of this contemporary assemblage were compared with those of a historical (pre-1965) assemblage, and the contribution of the three collecting methods used in the 2007 survey protocol was evaluated. Estimates of species richness indicated that Malaise traps yielded more species than did pan traps or sweep netting, and that species composition did not differ significantly between Malaise trap and pan trap catches. These results suggest that Malaise traps and sweep netting are adequate methods to survey northern Muscidae. We report little difference in estimated species richness and composition between time periods for material collected by sweep netting. When all material from the 2007 survey was pooled, 87% of the pre-1965 species were collected again in 2007. Most nonoverlapping species between time periods were rare in samples and (or) collected by different methods, suggesting a failure to detect as the most likely explanation for their absence in one assemblage. Nevertheless, the proportion of aquatic and semiaquatic species of Spilogona Schnabl was more than twice as high in the list of species not recovered in 2007 than in the pre-1965 assemblage.

scholarly journals Post-fire consequences for leaf breakdown in a tropical stream

2019 ◽  
Vol 31 ◽  
Author(s):  
Renan de Souza Rezende ◽  
Cristiano Queiroz de Albuquerque ◽  
Andrezza Sayuri Victoriano Hirota ◽  
Paulo Fernandes Roges Souza Silva ◽  
Ricardo Keichi Umetsu ◽  
...  
Keyword(s):  
Leaf Litter ◽  
Fungal Biomass ◽  
Mesh Size ◽  
Fire Effects ◽  
Dry Mass ◽  
Tropical Stream ◽  
Fire Event ◽  
Litter Bags ◽  
Fine Mesh ◽  
Post Fire Effects

Abstract Aim Wildfire is a natural pulsed disturbance in landscapes of the Savannah Biome. This study evaluates short-term post-fire effects on leaf litter breakdown, the invertebrate community and fungal biomass of litter from three different vegetal species in a tropical stream. Methods Senescent leaves of Inga laurina, Protium spruceanum and Rircheria grandis (2 ± 0.1 g dry mass) were individually placed in litter bags (30 × 30 cm: 10 mm coarse mesh and 0.5 mm fine mesh) and submerged in the study stream before and after fire. Replicate bags (n = 4; individually for each species, sampling time, fire event and mesh size) were then retrieved after 20 and 40 days and washed to separate the invertebrates before fire event and again immediately after fire. Disks were cut from leaves to determine ash-free dry mass, while the remaining material was oven-dried to determine dry mass. Results The pre-fire mean decomposition coefficient (k = -0.012 day-1) was intermediate compared to that reported for other savannah streams, but post-fire it was lower (k = -0.007 day-1), due to decreased allochthonous litter input and increased autochthones production. Intermediate k values for all qualities of litter post-fire may indicate that fire is equalizing litter quality in the stream ecosystem. The abundance of scrapers was found to be more important than fungal biomass or shredder abundance, probably due to their functioning in leaf fragmentation while consuming periphyton growing on leaf litter. Conclusions Theses results indicate that fire can modify the relationships within decomposer communities in tropical stream ecosystems.

scholarly journals An Alpine Malaise trap

2018 ◽  
Vol 2 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Shasta Claire Henry ◽  
Peter B. McQuillan ◽  
James B. Kirkpatrick
Keyword(s):  
Low Cost ◽  
Sampling Period ◽  
Rough Terrain ◽  
Light Weight ◽  
Malaise Trap ◽  
Remote Locations ◽  
Insect Trap ◽  
Rapid Deployment ◽  
Alpine Environments ◽  
Malaise Traps

The Southernmost region of Australia, the island of Tasmania, is also the most mountainous, with large areas of rugged alpine environments. This entomological frontier offers a distinct suite of insects for study including many endemic taxa. However, harsh weather, remote locations and rough terrain represent an environment too extreme for many existing insect trap designs. We report here on the design and efficacy of a new Alpine Malaise Trap (AMT), which can be readily hybridised with several other common insect trapping techniques. Advantages of the design include its light weight and portability, low cost, robustness, rapid deployment and long autonomous sampling period. The AMT was field tested in the Tasmanian highlands (AUST) in 2017. A total of 16 orders were collected. As expected, samples are dominated by Diptera. However, the trap also collected a range of flightless taxa including endemic and apterous species, Apteropanorpatasmanica – closest relative of the boreal, snow scorpionflies (Boreidae). Combined and compared with other trap types the Alpine Malaise Traps captured less specimens but of a greater diversity than passive sticky traps, while drop traps captured less specimens but a greater diversity than AMT. The statistical potential of the catch is discussed.

scholarly journals Effects of Malaise trap spacing on species richness and composition of terrestrial arthropod bulk samples

2020 ◽  
Author(s):  
D Steinke ◽  
TWA Braukmann ◽  
L Manerus ◽  
A Woodhouse ◽  
V Elbrecht
Keyword(s):  
Species Richness ◽  
Field Experiments ◽  
Collection Efficiency ◽  
Malaise Trap ◽  
Number Of Factors ◽  
Large Numbers ◽  
Set Up ◽  
Taxonomic Groups ◽  
A Site ◽  
Malaise Traps

AbstractThe Malaise trap has gained popularity for assessing diverse terrestrial arthropod communities because it collects large samples with modest effort. A number of factors that influence collection efficiency, placement being one of them. For instance, when designing larger biotic surveys using arrays of Malaise traps we need to know the optimal distance between individual traps that maximises observable species richness and community composition. We examined the influence of spacing between Malaise traps by metabarcoding samples from two field experiments at a site in Waterloo, Ontario, Canada. For one experiment, we used two trap pairs deployed at weekly increasing distance (3m increments from 3 to 27 m). The second experiment involved a total of 10 traps set up in a row at 3m distance intervals for three consecutive weeks.Results show that community similarity of samples decreases over distance between traps. The amount of species shared between trap pairs shows drops considerably at about 15m trap-to-trap distance. This change can be observed across all major taxonomic groups and for two different habitat types (grassland and forest). Large numbers of OTUs found only once within samples cause rather large dissimilarity between distance pairs even at close proximity. This could be caused by a large number of transient species from adjacent habitat which arrive at the trap through passive transport, as well as capture of rare taxa, which end up in different traps by chance.

Experimental and Numerical Plastic Response and Failure of Laterally Impacted Rectangular Plates

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
B. Liu ◽  
R. Villavicencio ◽  
C. Guedes Soares
Keyword(s):  
Finite Element ◽  
Numerical Simulations ◽  
Failure Modes ◽  
Mesh Size ◽  
Plastic Behavior ◽  
Finite Element Models ◽  
Rectangular Plates ◽  
Marine Structures ◽  
Fine Mesh ◽  
The Impact

Experimental and numerical results of drop weight impact test are presented on the plastic behavior and fracture of rectangular plates stuck laterally by a mass with a hemispherical indenter. Six specimens were tested in order to study the influence of the impact velocity and the diameter of the indenter. The impact scenarios could represent abnormal actions on marine structures, such as ship collision and grounding or dropped objects on deck structures. The tests are conducted on a fully instrumented impact tester machine. The obtained force-displacement response is compared with numerical simulations, performed by the LS-DYNA finite element solver. The simulations aim at proposing techniques for defining the material and restraints on finite element models which analyze the crashworthiness of marine structures. The mesh size and the critical failure strain are predicted by numerical simulations of the tensile tests used to obtain the mechanical properties of the material. The experimental boundary conditions are modeled in order to represent the reacting forces developed during the impact. The results show that the critical impact energy until failure is strongly sensitive to the diameter of the striker. The shape of the failure modes is well predicted by the finite element models when a relatively fine mesh is used. Comments on the process of initiation and propagation of fracture are presented.

scholarly journals An Adaptive Approach to Solutions of Fredholm Integral Equations of the Second Kind

2014 ◽  
Vol 2014 ◽  
pp. 1-13
Author(s):  
Nebiye Korkmaz ◽  
Zekeriya Güney
Keyword(s):  
Galerkin Method ◽  
Integral Equations ◽  
Iteration Method ◽  
Legendre Polynomials ◽  
Optimization Problem ◽  
Approximate Solutions ◽  
Basis Functions ◽  
Fredholm Integral Equations ◽  
Coarse Mesh ◽  
Fine Mesh

As an approach to approximate solutions of Fredholm integral equations of the second kind, adaptive hp-refinement is used firstly together with Galerkin method and with Sloan iteration method which is applied to Galerkin method solution. The linear hat functions and modified integrated Legendre polynomials are used as basis functions for the approximations. The most appropriate refinement is determined by an optimization problem given by Demkowicz, 2007. During the calculationsL2-projections of approximate solutions on four different meshes which could occur between coarse mesh and fine mesh are calculated. Depending on the error values, these procedures could be repeated consecutively or different meshes could be used in order to decrease the error values.

scholarly journals Detecting radiolaria in the field

1991 ◽  
Vol 10 (1) ◽  
pp. 22-22 ◽  
Author(s):  
Simon K. Haslett ◽  
Paul D. Robinson
Keyword(s):  
Rock Type ◽  
Fine Fraction ◽  
Field Work ◽  
Coarse Mesh ◽  
Extraction Techniques ◽  
The Past ◽  
Fine Mesh ◽  
Rock Types ◽  
Siliceous Rock ◽  
Calcareous Microfossils

Abstract. Radiolaria can be preserved in all types of marine sedimentary rocks, the method for their extraction being dependent on the mineralogy of the radiolarian test and the nature of the rock-type in which they occur. In the past radiolaria could only be viewed in thin section (Hinde, 1890; Hinde & Fox, 1895), with no method of detecting the presence of radiolaria prior to sectioning. Modern extraction techniques are normally laboratory based and use hazardous chemicals, therefore it is advantageous to establish the radiolarian content of the sample before collection and transportation back to the laboratory. This can be achieved in a number of ways:-1. Non-lithified sediments. Radiolaria are separated from the sediment by washing the sample over a set of small sieves. Two mesh sizes should be used, a coarse mesh around 150μm to separate large litho-fragments, and a fine mesh no greater than 63μm to concentrate the radiolaria. The fine fraction is then washed with dilute hydrochloric acid (HCl) to eliminate the calcareous microfossils, leaving a pure radiolarian sludge, which is dried on filter paper.2. Siliceous rock-types. Methods for extracting radiolaria from cherts have been in use since the early 1970’s (Dumitrica, 1970; Pessagno & Newport, 1972), and have recently been applied to field-work (Cordey & Krauss, 1990). The recognition of fossiliferous bedded cherts is possible with the use of a hand-lens in good sunlight. If radiolaria are present, they should be detectable as small protrusions, especially along laminae. To extract the radiolaria, break up the sample. . .

Modelling and Simulation of Temperature and Stress Analysis in TIG Welding Process

2015 ◽  
Vol 830-831 ◽  
pp. 294-297
Author(s):  
Nayan Chandak ◽  
Mohan Kumar Pradhan ◽  
Lokesh Boriwal
Keyword(s):  
Residual Stress ◽  
Structural Analysis ◽  
Strain State ◽  
Processing Time ◽  
Welding Process ◽  
Time Interval ◽  
Coarse Mesh ◽  
Ansys Software ◽  
Fine Mesh ◽  
Material Conditions

In this study, the welding process is modelled and analysed using ANSYS software. The temperature and residual stress produced during the process is depicted. During heating, the material conditions, parts affected by residual stress and the stress–strain state at different time interval is recorded and a subsequent structural analysis is used for the analysis, the same is used in the analysis where thermal and structural results are investigated. Subsequently, with sensitivity analysis the results are evaluated. Non-uniform meshing is used to entrap the result with fine mesh in the heat affected zone and coarse mesh away from it to save processing time. The results from the thermal structural analysis are presented to understand the process deeply and comparison of the graph plot between temperature and time is explained.

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