scholarly journals Performance of Trichograma spp in small tomato borer (Neoleucinodes elegantalis Guenée): Pest management with egg parasitoid

2020 ◽  
Vol 42 ◽  
pp. e46915
Author(s):  
José Romário de Carvalho ◽  
Luis Moreira de Araujo Junior ◽  
Dirceu Pratissoli ◽  
Débora Fragoso ◽  
Amanda Túler
Keyword(s):  
Technological Development ◽  
Physicochemical Characteristics ◽  
Egg Parasitoid ◽  
Optimal Number ◽  
Small Fruit ◽  
Fruit Borer ◽  
Alternative Techniques ◽  
Tomato Borer ◽  
Number Of Individuals ◽  
Selection Of

The tomato is a crop of great importance for Brazilian agriculture. Among the most damaging pests, the small tomato borer, Neoleucinodes elegantalis Guenée (Lepidoptera: Crambiadae) has caused great losses, since they directly reach the fruits to be commercialized, being used for its handling a large volume of insecticides. In this way, the use of alternative techniques that help in the management of this pest becomes of great importance. Among them, the use of the egg parasitoid Trichogramma spp. has been promising. Thus, the present study aimed to evaluate the performance of Trichogramma species and/or strains in N. elegantalis by selection of strains. The selection was made based on four lineages maintained in the Nucleus of Scientific and Technological Development in Phytosanitary Management of Pests (NUDEMAFI), being three strains of the species T. pretiosum and one of T. galloi species. The parameters evaluated were percentage of parasitized eggs, egg viability, number of individuals per eggs, sex ratio and number of Trichogramma spp. to be released. The T. galloi (T. g1) showed the best parameters for selection of the strain. Estimating the optimal number of T. g1 in eggs of small-fruit-borer was 82 individuals per egg parasitoid. Therefore, this strain was selected for the management of the small tomato-borer, whose eggs presented favorable physicochemical characteristics for the development of the parasitoid.

Capacity for Parasitism of Trichogramma spp. in Tomato Fruit Borer under Different Temperatures

2019 ◽  
pp. 1-8
Author(s):  
Débora Ferreira Melo Fragoso ◽  
Dirceu Pratissoli ◽  
José Romario De Carvalho ◽  
Alixelhe Pacheco Damascena ◽  
Luis Moreira de Araujo Junior ◽  
...  
Keyword(s):  
Technological Development ◽  
Tomato Fruit ◽  
Biological Parameters ◽  
Thermal Range ◽  
Fruit Borer ◽  
Different Temperatures ◽  
Number Of Individuals ◽  
Number Of Males ◽  
Scientific And Technological Development ◽  
The Ideal

The parasitoid in eggs of Trichogramma genre is the most studied in the world, being bred widely and used for flooding releases. This study aimed to evaluate the capacity for parasitism of Trichogramma galloi Zucchi, 1988 (Hymenoptera: Trichogrammatidae) in Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae) eggs at different temperatures. The experiment was developed at the Nucleus for Scientific and Technological Development in Phytosanitary Management (NUDEMAFI) in which the daily and accumulated biological parameters were assessed, as well as total parasitized eggs by female, sexual ratio (number of females/number of males + females), viability of the eggs (number of eggs with orifice/number of parasitized eggs x 100) and number of individuals per egg at temperatures 18, 21, 24, 27 and 30ºC. The eggs of the fruit borer were offered daily to each T. galloi female at each temperature until the death of the parasitoid could be verified. The larger number of parasitized eggs was found in the first 24 h, at temperatures 24 and 27ºC with 17 parasitized eggs. The accumulated parasitism in N. elegantalis eggs reached 80% of total parasitized eggs for each thermal range (18, 21, 24, 27 and 30ºC) on the 2nd, 3rd, 3rd, 1st and 2nd days respectively. The ideal parasitism conditions for this lineage vary between 24 and 27°C. Therefore, it is concluded that the studied T. galloi lineage has adequate biological parameters in N. elegantalis eggs, demonstrating promise in phytosanitary management of this pest.

Optimal Experimental Design With Nesting of Persons in Organizations

2013 ◽  
Vol 221 (3) ◽  
pp. 145-159 ◽  
Author(s):  
Gerard J. P. van Breukelen
Keyword(s):  
Repeated Measures ◽  
Optimal Number ◽  
Health Centers ◽  
Randomized Experiments ◽  
Optimal Sample ◽  
Treatment Conditions ◽  
Sampling Cost ◽  
Nested Designs ◽  
Simple Equations ◽  
Number Of Individuals

This paper introduces optimal design of randomized experiments where individuals are nested within organizations, such as schools, health centers, or companies. The focus is on nested designs with two levels (organization, individual) and two treatment conditions (treated, control), with treatment assignment to organizations, or to individuals within organizations. For each type of assignment, a multilevel model is first presented for the analysis of a quantitative dependent variable or outcome. Simple equations are then given for the optimal sample size per level (number of organizations, number of individuals) as a function of the sampling cost and outcome variance at each level, with realistic examples. Next, it is explained how the equations can be applied if the dependent variable is dichotomous, or if there are covariates in the model, or if the effects of two treatment factors are studied in a factorial nested design, or if the dependent variable is repeatedly measured. Designs with three levels of nesting and the optimal number of repeated measures are briefly discussed, and the paper ends with a short discussion of robust design.

scholarly journals An Algorithm for Choosing the Optimal Number of Muscle Synergies during Walking

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3311
Author(s):  
Riccardo Ballarini ◽  
Marco Ghislieri ◽  
Marco Knaflitz ◽  
Valentina Agostini
Keyword(s):  
Motor Task ◽  
Optimal Number ◽  
The Other ◽  
Simulated Dataset ◽  
Muscle Synergies ◽  
Mean Square ◽  
Real Dataset ◽  
Traditional Approaches ◽  
Selection Of ◽  
Semg Signals

In motor control studies, the 90% thresholding of variance accounted for (VAF) is the classical way of selecting the number of muscle synergies expressed during a motor task. However, the adoption of an arbitrary cut-off has evident drawbacks. The aim of this work is to describe and validate an algorithm for choosing the optimal number of muscle synergies (ChoOSyn), which can overcome the limitations of VAF-based methods. The proposed algorithm is built considering the following principles: (1) muscle synergies should be highly consistent during the various motor task epochs (i.e., remaining stable in time), (2) muscle synergies should constitute a base with low intra-level similarity (i.e., to obtain information-rich synergies, avoiding redundancy). The algorithm performances were evaluated against traditional approaches (threshold-VAF at 90% and 95%, elbow-VAF and plateau-VAF), using both a simulated dataset and a real dataset of 20 subjects. The performance evaluation was carried out by analyzing muscle synergies extracted from surface electromyographic (sEMG) signals collected during walking tasks lasting 5 min. On the simulated dataset, ChoOSyn showed comparable performances compared to VAF-based methods, while, in the real dataset, it clearly outperformed the other methods, in terms of the fraction of correct classifications, mean error (ME), and root mean square error (RMSE). The proposed approach may be beneficial to standardize the selection of the number of muscle synergies between different research laboratories, independent of arbitrary thresholds.

Failed predation in Late Ordovician gastropods (Mollusca) from Manitoulin Island, Ontario, CanadaThis article is one of a selection of papers published in this Special Issue on the theme The dynamic reef and shelly communities of the Paleozoic. This Special is in honour of our colleague and friend Paul Copper.

2008 ◽  
Vol 45 (2) ◽  
pp. 231-241 ◽  
Author(s):  
Jan Ove R. Ebbestad ◽  
Christopher A. Stott
Keyword(s):  
Success Rate ◽  
Late Ordovician ◽  
Size Class ◽  
Low Energy ◽  
Special Issue ◽  
Georgian Bay ◽  
Low Level ◽  
Shell Repair ◽  
Number Of Individuals ◽  
Selection Of

Shell repairs resulting from presumed failed predation are documented in gastropods from the Late Ordovician (Cincinnatian; Richmondian) mid-to-upper Kagawong Submember of the Georgian Bay Formation on Manitoulin Island, Ontario, Canada. The bryozoan–mollusc biota and associated sediments generally suggest nearshore, shallow (<10 m), low energy (lagoonal), and perhaps mesotrophic to eutrophic conditions. Two sample sets from this unit have been studied for shell repair. One of the more commonly applied estimates of shell repair frequencies involves division of the number of individuals with at least one scar by the total number of individuals in the sample (the Individuals with scars method). Using this calculation, 207 specimens of Lophospira trilineata Ulrich and Scofield yielded a shell repair frequency of 4.8%; in 28 specimens of Trochonemella sp. the shell repair frequency was 35.7%. Repairs in Trochonemella occur primarily in the larger size class, suggesting that a size refuge was achieved by this species. Low repair frequencies in L. trilineata suggest predation with a higher success rate or fewer encounters. This study demonstrates that the paradigm of a standardized low level of shell repair in Ordovician and Silurian gastropods is oversimplistic and a range of frequency rates can be expected.

scholarly journals Likert scale and change in range of response categories vs. the factors extraction in EFA model

2015 ◽  
Vol 1 (311) ◽  
Author(s):  
Piotr Tarka
Keyword(s):  
Factor Analysis ◽  
Exploratory Factor Analysis ◽  
Rating Scale ◽  
Likert Scale ◽  
Optimal Number ◽  
Number Of Factors ◽  
Scale Experiment ◽  
Methodological Aspects ◽  
The Impact ◽  
Selection Of

Abstract: The objective article is the comparative analysis of Likert rating scale based on the following range of response categories, i.e. 5, 7, 9 and 11 in context of the appropriate process of factors extraction in exploratory factor analysis (EFA). The problem which is being addressed in article relates primarily to the methodological aspects, both in selection of the optimal number of response categories of the measured items (constituting the Likert scale) and identification of possible changes, differences or similarities associated (as a result of the impact of four types of scales) with extraction and determination the appropriate number of factors in EFA model.Keywords: Exploratory factor analysis, Likert scale, experiment research, marketing

scholarly journals The emergence and selection of reputation systems that drive cooperative behaviour

2018 ◽  
Vol 285 (1886) ◽  
pp. 20181508 ◽  
Author(s):  
Alain Schlaepfer
Keyword(s):  
Computer Simulations ◽  
Relevant Information ◽  
Reputation Systems ◽  
Cooperative Behaviour ◽  
Social Image ◽  
Reputation Mechanism ◽  
Initial Evolution ◽  
Group Members ◽  
Number Of Individuals ◽  
Selection Of

Reputational concerns are believed to play a crucial role in explaining cooperative behaviour among non-kin humans. Individuals cooperate to avoid a negative social image, if being branded as defector reduces pay-offs from future interactions. Similarly, individuals sanction defectors to gain a reputation as punisher, prompting future co-players to cooperate. But reputation can only effectively support cooperation if a sufficient number of individuals condition their strategies on their co-players' reputation, and if a sufficient number of group members are willing to record and transmit the relevant information about past actions. Using computer simulations, this paper argues that starting from a pool of non-cooperative individuals, a reputation system based on punishment is likely to emerge and to be the driver of the initial evolution of cooperative behaviour. However, once cooperation is established in a group, it will be sustained mainly through a reputation mechanism based on cooperative actions.

Investigating cluster validation metrics for optimal number of clusters determination

2021 ◽  
pp. 1-16
Author(s):  
Aikaterini Karanikola ◽  
Charalampos M. Liapis ◽  
Sotiris Kotsiantis
Keyword(s):  
Real World ◽  
Optimal Number ◽  
Cluster Validation ◽  
Clustering Methods ◽  
Number Of Clusters ◽  
Validity Indices ◽  
Selection Of ◽  
Specific Distance ◽  
Optimal Number Of Clusters

In short, clustering is the process of partitioning a given set of objects into groups containing highly related instances. This relation is determined by a specific distance metric with which the intra-cluster similarity is estimated. Finding an optimal number of such partitions is usually the key step in the entire process, yet a rather difficult one. Selecting an unsuitable number of clusters might lead to incorrect conclusions and, consequently, to wrong decisions: the term “optimal” is quite ambiguous. Furthermore, various inherent characteristics of the datasets, such as clusters that overlap or clusters containing subclusters, will most often increase the level of difficulty of the task. Thus, the methods used to detect similarities and the parameter selection of the partition algorithm have a major impact on the quality of the groups and the identification of their optimal number. Given that each dataset constitutes a rather distinct case, validity indices are indicators introduced to address the problem of selecting such an optimal number of clusters. In this work, an extensive set of well-known validity indices, based on the approach of the so-called relative criteria, are examined comparatively. A total of 26 cluster validation measures were investigated in two distinct case studies: one in real-world and one in artificially generated data. To ensure a certain degree of difficulty, both real-world and generated data were selected to exhibit variations and inhomogeneity. Each of the indices is being deployed under the schemes of 9 different clustering methods, which incorporate 5 different distance metrics. All results are presented in various explanatory forms.

scholarly journals Mortality of Conotrachelus humeropictus in response to combined application of the nematode Steinernema brazilense and the fungus Beauveria bassiana

2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Lucas Detogni Simi ◽  
Luís Garrigós Leite ◽  
Olzeno Trevisan ◽  
José Nilton Medeiros Costa ◽  
Leandro Ezequiel Oliveira ◽  
...  
Keyword(s):  
Beauveria Bassiana ◽  
Control Method ◽  
Entomopathogenic Nematode ◽  
Field Trials ◽  
Additive Interaction ◽  
Soil Layers ◽  
Combined Application ◽  
Fruit Borer ◽  
Beauveria Bassiana Isolates ◽  
Selection Of

ABSTRACT: The fruit borer Conotrachelus humeropictus is one of the most important pests of the cupuaçu crop, and can promote yield losses of around 50%. The present study involved the selection of Beauveria bassiana isolates on Conotrachelus psidii larvae, which was used as test insect due to its taxonomic closeness to C. humeropictus. In order to assess their interaction using combined application, we studied the ability of the nematode to carry conidia of B. bassiana and Metarhizium anisopliae to soil layers. This study also aimed to establish a biological control method for cupuaçu borer with the use of the fungus B. bassiana at 10 kg/ha and the entomopathogenic nematode Steinernema brazilense at 1, 3, 9, and 27 IJ/cm2, applied as single and combined treatments. In the selection of B. bassiana strains for C. psidii, the IBCB 276 and IBCB 165 isolates were the most promising ones, causing 86 and 84% mortality, respectively. The IBCB 276 strain was applied in the field to control C. humeropictus. In the study of carriage of conidia in soil, the nematode S. brazilense was found to be capable of carrying conidia of B. bassiana to deep 7 to 10 cm soil layers. This was not observed with M. anisopliae, found only in the topsoil. In field trials against C. humeropictus larvae, B. bassiana promoted 15.6% mortality. The nematode promoted 60.0% mortality at the highest concentration used, and their combined use with B. bassiana (10 kg/ha) increased mortality to 65.6%, with an additive interaction observed between the two entomopathogens.

scholarly journals Features of the inheritance of fruit size in the hybrid families of prunus domestica

2020 ◽  
Vol 17 ◽  
pp. 00070
Author(s):  
G. E. Osipov ◽  
Z. A. Osipova
Keyword(s):  
Fruit Size ◽  
Recessive Trait ◽  
Fruit Crops ◽  
Prunus Domestica ◽  
Dominant Trait ◽  
Small Fruit ◽  
Russian Research Institute ◽  
Selection Of ◽  
Russian Research ◽  
Research Institute

The aim of the research was to establish the features of the inheritance of the size of the fruit in the hybrid families of Prunus domestica. The objects of study were hybrid seedlings of plum selection of the Tatar research Institute of agriculture. Fruit sizes were estimated according to the methodology of the all-Russian research Institute of fruit crops selection. The analysis of the splitting of plum in hybrid families by the size of fruits showed that seedlings with small fruits dominated in the breeding gardens of the Tatar research Institute. The size of the plum fruit is controlled by polygens. All of the original parental forms are heterozygotes for the genes determining the size of the fruit. A small fruit is a dominant trait, a large fruit is a recessive trait. In most hybrid families, plum seedlings have a significant variability in the size of the fruit. Transgressive genotypes with large fruits are formed in hybrid families Eurasia 21 x Renklod Tenkovsky, Eurasia 21 x free pollination and Zyuzinskaya x free pollination. The varieties Eurasia 21 and Zyuzinskaya must be used as sources in breeding of plums for large-fruited.

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