SAMPLING PLANS FOR ESTIMATING ACHENE DAMAGE BY THE RED SUNFLOWER SEED WEEVIL (COLEOPTERA: CURCULIONIDAE)

1995 ◽  
Vol 127 (1) ◽  
pp. 7-14 ◽  
Author(s):  
Chengwang Peng ◽  
Gary J. Brewer
Keyword(s):  
Sample Size ◽  
Distribution Pattern ◽  
Power Law ◽  
Sunflower Seed ◽  
Management Strategies ◽  
Economic Injury Level ◽  
Taylor’S Power Law ◽  
Precision Level ◽  
Taylor's Power Law ◽  
The Mean

AbstractA sampling plan for the estimation of the number of achenes damaged by the red sunflower seed weevil, Smicronyx fulvus LeConte, is useful in evaluating the efficiency of weevil management strategies. The objective of this study was to determine the distribution pattern of the damaged achenes that would allow the development of a fixed-sample-size plan for estimation of the damaged achenes. Taylor’s power law and Iwao’s patchiness regression were used to analyze the distribution pattern of the damaged achenes. Slopes from both models were >1, indicating an aggregated spatial pattern. The intercepts and slopes from both models were used to calculate the minimal mean number of damaged achenes per sunflower head that can be estimated for a given sample size and precision level. If the mean number of damaged achenes per head is low (<20), the plan developed using the parameters of Taylor’s power law requires significantly more samples than the plan using the parameters of Iwao’s patchiness regression to estimate the same density of damaged achenes. If the mean number of damaged achenes per head is high (>30), the two plans give similar results. If both low and high damage situations are considered, Taylor’s plan is preferred to Iwao’s plan. At the 0.10 precision level, Taylor’s plan requires approximately 40 samples (heads) to estimate a mean of about 200 damaged achenes per head (≈ current economic injury level).

Spatial distribution and sequential sampling of Nysius spp. (Hemiptera: Lygaeidae) on sunflowers

1988 ◽  
Vol 28 (2) ◽  
pp. 279 ◽  
Author(s):  
PG Allsopp ◽  
S Iwao ◽  
LR Taylor
Keyword(s):  
Power Law ◽  
Negative Binomial ◽  
Sequential Sampling ◽  
Binomial Model ◽  
Sequential Decision ◽  
Taylor’S Power Law ◽  
Crop Development ◽  
Precision Level ◽  
Taylor's Power Law ◽  
Mixed Populations

Counts of adults of mixed populations of Nysius vinitor Bergroth and N. clevelandensis Evans on preflowering and postflowering sunflowers did not conform to the Poisson distribution because of overdispersion. Preflowering samples did not conform to the negative binomial model, but postflowering samples did with a common k of 3.78. Both sets of samples fitted significantly (P<0.01) Iwao's patchiness regression and Taylor's power law, but with significantly (P<0.01) different intercepts and slopes, respectively. Relationships to determine sample sizes for fixed levels of precision and fixed-precision-level stop lines are developed for both stages of crop development using Taylor's power law. Sequential decision plans based on Iwao's regression are developed for use in the management of Nysius spp. on preflowering and postflowering sunflowers.

Taylor’s power law and fixed-precision sampling: application to abundance of fish sampled by gillnets in an African lake

2017 ◽  
Vol 74 (1) ◽  
pp. 87-100 ◽  
Author(s):  
Meng Xu ◽  
Jeppe Kolding ◽  
Joel E. Cohen
Keyword(s):  
Power Law ◽  
Fish Assemblage ◽  
Mesh Size ◽  
Stock Management ◽  
Taylor’S Power Law ◽  
Scaling Relationship ◽  
Temporal Variance ◽  
Taylor's Power Law ◽  
Power Law Function ◽  
The Mean

Taylor’s power law (TPL) describes the variance of population abundance as a power-law function of the mean abundance for a single or a group of species. Using consistently sampled long-term (1958–2001) multimesh capture data of Lake Kariba in Africa, we showed that TPL robustly described the relationship between the temporal mean and the temporal variance of the captured fish assemblage abundance (regardless of species), separately when abundance was measured by numbers of individuals and by aggregate weight. The strong correlation between the mean of abundance and the variance of abundance was not altered after adding other abiotic or biotic variables into the TPL model. We analytically connected the parameters of TPL when abundance was measured separately by the aggregate weight and by the aggregate number, using a weight–number scaling relationship. We utilized TPL to find the number of samples required for fixed-precision sampling and compared the number of samples when sampling was performed with a single gillnet mesh size and with multiple mesh sizes. These results facilitate optimizing the sampling design to estimate fish assemblage abundance with specified precision, as needed in stock management and conservation.

scholarly journals Spatial distribution and sampling of Corythucha ciliata (Hemiptera: Tingidae) in London plane trees

2019 ◽  
Vol 24 (1) ◽  
pp. 43-52
Author(s):  
He-Ping Wei ◽  
Feng Wang ◽  
Rui-Ting Ju
Keyword(s):  
Spatial Distribution ◽  
Distribution Pattern ◽  
Power Law ◽  
Distribution Data ◽  
Taylor’S Power Law ◽  
Control Threshold ◽  
Dispersion Patterns ◽  
Plane Trees ◽  
Taylor's Power Law ◽  
London Plane

Taylor’s power law and Iwao’s patchiness regression were used to describe the dispersion patterns for overwintering and wandering stages of Corythucha ciliata on the London plane trees, Platanus x acerifolia (Ait.) Willd. Both Taylor’s and Iwao’s tests fit the distribution data for the overwintering stage. The overwintering adults were spatially aggregated. In the wandering stage, Taylor’s power law consistently fit the data, whereas the fit of Iwao’s patchiness regression was erratic. Both Iwao’s and Taylor’s indices indicated a clumped distribution pattern for eggs, nymphs, and wandering adults. Trunk was identified as the best sampling target for the overwintering stage whereas twig was the best for the wandering stage. In order to determine the sample size for evaluating whether the population has reached the control threshold, the sampling of 35 and 7 trunks for the overwintering stage and 32 and 8 twigs per tree for the wandering stage would provide 0.5- and 0.25-precision levels, respectively.

scholarly journals Statistical Analysis of Root Count Data

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 907A-907
Author(s):  
D. Michael Glenn
Keyword(s):  
Statistical Analysis ◽  
Analysis Of Variance ◽  
Power Law ◽  
Count Data ◽  
Root Systems ◽  
Trial And Error ◽  
Taylor’S Power Law ◽  
First Approximation ◽  
Taylor's Power Law ◽  
The Mean

The minirhizotron approach for studying the dynamics of root systems is gaining acceptance; however, problems have arisen in the analysis of data. The purposes of this study were to determine if analysis of variance (ANOVA) was appropriate for root count data, and to evaluate transformation procedures to utilize ANOVA. In peach, apple, and strawberry root count data, the variance of treatment means was positively correlated with the mean, violating assumptions of ANOVA. A transformation based on Taylor's power law as a first approximation, followed by a trial and error approach, developed transformations that reduced the correlation of variance and mean.

Distribution pattern of benthic invertebrates in Danish estuaries: The use of Taylor's power law as a species-specific indicator of dispersion and behavior

2013 ◽  
Vol 77 ◽  
pp. 70-78 ◽  
Author(s):  
Erik Kristensen ◽  
Matthieu Delefosse ◽  
Cintia O. Quintana ◽  
Gary T. Banta ◽  
Hans Christian Petersen ◽  
...  
Keyword(s):  
Distribution Pattern ◽  
Power Law ◽  
Benthic Invertebrates ◽  
Taylor’S Power Law ◽  
Taylor's Power Law ◽  
Species Specific ◽  
And Behavior

scholarly journals A Taylor's power law in the Wenchuan earthquake sequence with fluctuation scaling

2018 ◽  
Author(s):  
Peijian Shi ◽  
Mei Li ◽  
Yang Li ◽  
Jie Liu ◽  
Haixia Shi ◽  
...  
Keyword(s):  
Wenchuan Earthquake ◽  
Power Law ◽  
Temporal Distribution ◽  
Earthquake Sequence ◽  
Biomedical Sciences ◽  
Taylor’S Power Law ◽  
The Wenchuan Earthquake ◽  
Taylor's Power Law ◽  
The Mean ◽  
Wenchuan Earthquake Sequence

Abstract. Taylor's power law (TPL) describes the scaling relationship between the temporal or spatial variance and mean of population densities by a simple power law. TPL is widely testified across space and time in biomedical sciences, botany, ecology, economics, epidemiology, and other fields. In this paper, TPL is analytically reconfirmed by testifying the variance as a function of the mean of the released energy of earthquakes with different magnitudes on varying timescales during the Wenchuan earthquake sequence. Estimates of the exponent of TPL are approximately 2, showing that there is mutual attraction among the events in the sequence. On the other hand, the spatial–temporal distribution of the Wenchuan aftershocks tends to be nonrandom but approximately definite and deterministic. Effect of different divisions on estimation of the intercept of TPL straight line has been checked while the exponent is kept to be 2. The result shows that the intercept acts as a logarithm function of the time division. It implies that the mean–variance relationship of the energy release from the earthquakes can be predicted although we cannot accurately predict the occurrence time and locations of imminent events.

scholarly journals Prediction of Infestation by Beetles in Stored Wheat Using Two Sampling Methods

2017 ◽  
Vol 14 ◽  
pp. 19
Author(s):  
G. Athanassiou ◽  
C. Th. Buchelos
Keyword(s):  
Power Law ◽  
Sitophilus Oryzae ◽  
Abundant Species ◽  
Taylor’S Power Law ◽  
Stored Wheat ◽  
Taylor's Power Law ◽  
The Mean ◽  
Trap Catches ◽  
Steel Silos ◽  
Sufficient Precision

Studies were conducted in order to assess the use of binomial sampling for prediction of infestation level in stored wheat. In each of three steel silos with 1500 metric tones of wheat each, located in central Greece, 14 probe traps were placed on 15 June 1997. The traps were checked for adult coleoptera. every 15 days, from 30 June until 30 January 1998. On the same dates, 14 wheat samples were taken adjacent to the trap locations, using a grain trier. Most abundant species were found to be Cryptolestesferrugineus and Tribolium castaneum in the traps, while Sitophilus oryzae in the samples. Regarding all species detected, traps were proved to be more effective as compared to the samples. Taylor’s Power Law was used, in order to estimate y-intercept and slope values for each species, The comparison of these parameters indicated that a single (weighted) equation can describe equally well the relation between the mean and the variance, according to Taylor’s Power Law, for all adults found, regardless of species. The parameters of this relation were utilized to connect the ratio of sampling units containing one or more adults and the mean number of adults per sampl i ng unit (x), using Wilson and Room’s model. Regarding trap catches, the same model can he used to predict an infestation, with a sufficient precision level, mainly when K<5; on the contrary, the results were not satisfactory in the case of adult numbers in the samples.

scholarly journals Taylor's power law in the Wenchuan earthquake sequence with fluctuation scaling

2019 ◽  
Vol 19 (6) ◽  
pp. 1119-1127 ◽  
Author(s):  
Peijian Shi ◽  
Mei Li ◽  
Yang Li ◽  
Jie Liu ◽  
Haixia Shi ◽  
...  
Keyword(s):  
Energy Release ◽  
Wenchuan Earthquake ◽  
Power Law ◽  
Earthquake Sequence ◽  
Biomedical Sciences ◽  
Taylor’S Power Law ◽  
The Wenchuan Earthquake ◽  
Taylor's Power Law ◽  
The Mean ◽  
Wenchuan Earthquake Sequence

Abstract. Taylor's power law (TPL) describes the scaling relationship between the temporal or spatial variance and mean of population densities by a simple power law. TPL has been widely testified across space and time in biomedical sciences, botany, ecology, economics, epidemiology, and other fields. In this paper, TPL is analytically reconfirmed by testifying the variance as a function of the mean of the released energy of earthquakes with different magnitudes on varying timescales during the Wenchuan earthquake sequence. Estimates of the exponent of TPL are approximately 2, showing that there is mutual attraction among the events in the sequence. On the other hand, the spatio-temporal distribution of the Wenchuan aftershocks tends to be nonrandom but approximately definite and deterministic, which highly indicates a stable spatio-temporally dependent energy release caused by regional stress adjustment and redistribution during the fault revolution after the mainshock. The effect of different divisions on estimation of the intercept of TPL straight line has been checked, while the exponent is kept to be 2. The result shows that the intercept acts as a logarithm function of the time division. It implies that the mean–variance relationship of the energy release from the earthquakes can be predicted, although we cannot accurately know the occurrence time and locations of imminent events.

Sequential sampling plans for nematodes affecting sugarcane in Queensland

1990 ◽  
Vol 41 (2) ◽  
pp. 351 ◽  
Author(s):  
PG Allsopp
Keyword(s):  
Power Law ◽  
Negative Binomial ◽  
Sequential Sampling ◽  
Taylor’S Power Law ◽  
Functional Relationships ◽  
Precision Level ◽  
Taylor's Power Law ◽  
Mean And Variance ◽  
Population Counts ◽  
The Relationship

The dispersion characteristics of root-lesion, root-knot, spiral, stubby-root, stunt and ring nematodes in soil, and root-lesion, root-knot and spiral nematodes in roots in sugarcane fields, were determined in studies in southern Queensland. The Poisson distribution, negative binomial distribution, Iwao's regression model and Taylor's power law analysis were used to determine the relationship between mean and variance of nematode counts. All methods showed that nematodes were aggregated (Iwao's G 1.12-1.65, Taylor's b 1.10-1.76). In general, Taylor's power law gave better fit compared with the other models (R2>0.61). Relationships to determine sample sizes for fixed levels of precision and fixed-precision-level stop lines for sequential sampling were developed for all species. There were functional relationships between variance and mean of untransformed population counts for all species, but suitable transformations eliminated significant correlations in most cases.

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