DEVELOPMENT OF SAMPLING TECHNIQUES FOR THE SPRUCE BUDMOTH, ZEIRAPHERA CANADENSIS MUT. AND FREE. (LEPIDOPTERA: TORTRICIDAE)

1987 ◽  
Vol 119 (3) ◽  
pp. 239-249 ◽  
Author(s):  
Jean J. Turgeon ◽  
Jacques Régnière
Keyword(s):  
New Brunswick ◽  
Sequential Sampling ◽  
White Spruce ◽  
Sampling Techniques ◽  
Growth Reduction ◽  
Density Estimates ◽  
Sample Unit ◽  
Sequential Sampling Plan ◽  
Branch Segment ◽  
Eggs And Larvae

AbstractThe spatial and statistical distribution of Zeiraphera canadensis Mut. and Free. (spruce budmoth) within the crown of white spruce (< 4 m high) was investigated in northern New Brunswick. A 15-cm branch segment, measured distally from the scales of the branch’s apical growth and taken from the upper one-third of the crown, is considered an adequate sample unit for density estimates of spruce budmoth eggs and larvae. Sample sizes required to estimate spruce budmoth larval densities with given levels of precision and confidence were determined. A sequential sampling plan to classify spruce budmoth populations as low or high (potentially leading to growth reduction and deformed leaders in white spruce) was also developed.

DEVELOPMENT OF SAMPLING DESIGNS FOR EGG AND LARVAL POPULATIONS OF THE WHEAT MIDGE, SITODIPLOSIS MOSELLANA (GÉHIN) (DIPTERA: CECIDOMYIIDAE), IN WHEAT

1988 ◽  
Vol 120 (6) ◽  
pp. 497-505 ◽  
Author(s):  
M.K. Mukerji ◽  
O.O. Olfert ◽  
J.F. Doane
Keyword(s):  
Sequential Sampling ◽  
Sampling Plan ◽  
Statistical Distribution ◽  
Life Stages ◽  
Density Estimates ◽  
Sitodiplosis Mosellana ◽  
Sample Unit ◽  
Sequential Sampling Plan ◽  
Wheat Midge ◽  
Eggs And Larvae

AbstractThe spatial and statistical distribution of eggs and larvae of the wheat midge, Sitodiplosis mosellana (Géhin), in wheat in northeastern Saskatchewan were investigated. The highest number of each stage occurred in the top third of the head and the lowest in the bottom third. Because of this the entire wheat head is considered an adequate sample unit for density estimates of the two life stages. Sample sizes required to estimate egg and larval populations with given levels of precision were determined. A sequential sampling plan for larval populations was derived using Green’s and Iwao’s methods. Both methods gave similar results; however, the number of samples required to reach a decision was higher using Green’s method than using Iwao’s.

Evaluation of Two-Leaf Sampling Units to Estimate Sugarcane Aphid (Hemiptera: Aphididae) Economic Thresholds in Commercial Grain Sorghum

2020 ◽  
Author(s):  
Jessica C Lindenmayer ◽  
Mark Payton ◽  
Kris L Giles ◽  
Norman C Elliott ◽  
Allen E Knutson ◽  
...  
Keyword(s):  
Sequential Sampling ◽  
Grain Sorghum ◽  
Sampling Plan ◽  
Growth Stages ◽  
Leaf Sample ◽  
Sample Unit ◽  
Sequential Sampling Plan ◽  
Sugarcane Aphid ◽  
Economic Thresholds ◽  
Leaf Sampling

Abstract Sugarcane aphid Melanaphis sacchari Zehntner is a significant economic pest of grain sorghum in the United States. Effective monitoring and early detection are cornerstones for managing invasive pests. The recently developed binomial sequential sampling plan estimates sugarcane aphid economic thresholds (ETs) based on classification whether a 2-leaf sample unit has ≤ or ≥ 50 M. sacchari. In this study, we evaluated eight 2-leaf sampling units for potential use in the sequential sampling plan. From 2016 through 2017, whole plant counts of M. sacchari were recorded non-destructively in situ on sorghum plants from 140 fields located in five states. Plant canopies were stratified into three categories. Two leaves from each stratum were used to compare linear relationships between M. sacchari numbers per two-leaf sample unit and total M. sacchari density per plant. Analysis revealed that two randomly selected leaves from the middle stratum accounted more variation for estimating M. sacchari density when compared to two leaves from the other strata. Comparison of eight two-leaf sampling units within plant growth stages were variable in quantifying variation of M. sacchari densities. When growth stages were combined, the standard uppermost + lowermost leaf sample unit and a unit consisting of two randomly selected leaves from the middle stratum revealed little difference in their enumeration of variation in M. sacchari density. Because other sample units were either less predictive and/or more variable in estimating M. sacchari density, we suggest that the (L1+U1) sample unit remain the preferred method for appraising M. sacchari ETs.

Population studies of white spruce. II. Natural inbreeding and relatedness among neighboring trees

1984 ◽  
Vol 14 (6) ◽  
pp. 909-913 ◽  
Author(s):  
Y. S. Park ◽  
D. P. Fowler ◽  
J. F. Coles
Keyword(s):  
New Brunswick ◽  
Population Studies ◽  
White Spruce ◽  
Early Growth ◽  
Height Growth ◽  
The Self ◽  
Open Pollination ◽  
Early Seedling ◽  
Natural Stands ◽  
Lethal Genes

Natural inbreeding and relatedness among neighboring trees were studied in several central New Brunswick populations of white spruce (Piceaglauca (Moench) Voss). Coefficients of relationship (r) were estimated by comparing the self-, neighbor-, open-, and unrelated-pollination effects on percent full seed. The estimates were 0.29 and 0.28 for neighbor and open pollinations, respectively. The effects of natural inbreeding on juvenile traits, e.g., germination and early growth, were slight while the effect on height growth increased with age at least to age 7 years. Neighboring white spruce trees growing in natural stands appear to be related at about the half-sib level (r = 0.25). Based on percent full seed, open-pollination approximates a level of inbreeding expected from trees related at a level well above that of half-sibs. Differential selection at the pre-embryo to early seedling stages results in progenies again related at the half-sib level. It is suggested that an inbreeding equilibrium exists in natural stands of white spruce and that this equilibrium approximates that expected from half-sib matings (F = 0.125). The inbreeding equilibrium is controlled, at least in part, by the frequency of lethal genes in the populations.

scholarly journals Within-plant distribution and binomial sequential sampling plan for Tetranychus evansi (Acari: Tetranychidae) in greenhouse tomato: implications for management.

2020 ◽  
Author(s):  
Willis Ndeda Ochilo ◽  
Gideon Nyamasyo ◽  
John Agano
Keyword(s):  
Sequential Sampling ◽  
Sampling Plan ◽  
Plant Distribution ◽  
Tetranychus Evansi ◽  
Sequential Sampling Plan ◽  
Red Spider Mite ◽  
Mite Density ◽  
Density Analysis ◽  
The Tropics ◽  
Best Fit

Abstract The red spider mite, Tetranychus evansi is a critical pest of tomato in the tropics. Control of T. evansi has traditionally depended on acaricide treatments. However, it is only in a handful of crops where monitoring techniques for mites, using statistical methods, have been developed to help farmers decide when to spray. The objective of this study, therefore, was to develop a sampling plan that would help farmers increase accuracy, and reduce the labor and time needed to monitor T. evansi on tomato. The distribution of T. evansi within-plant was aggregated, and intermediate leaves (YFL) was the most appropriate sampling unit to evaluate the mite density. Analysis based on Taylor's Power Law showed an aggregated pattern of distribution of T. evansi, while assessment of the fitness of the binomial model indicated that a tally threshold of 5 mites per YFL provided the best fit. Consequently, binomial sequential sampling plans premised on three action thresholds (0.1, 0.2 and 0.3) were developed. The binomial sequential sampling plan for T. evansi developed in this study has the potential to significantly increase the chance for targeted acaricide applications. This judicious use of pesticides is especially crucial within the context of integrated pest management (IPM).

scholarly journals SPATIAL DISTRIBUTION AND SEQUENTIAL SAMPLING OF Brevipalpus phoenicis IN CITRUS

2016 ◽  
Vol 38 (4) ◽  
Author(s):  
WALTER MALDONADO JR ◽  
JOSÉ CARLOS BARBOSA ◽  
MARÍLIA GREGOLIN COSTA ◽  
PAULO CÉSAR TIBURCIO GONÇALVES ◽  
TIAGO ROBERTO DOS SANTOS
Keyword(s):  
Spatial Distribution ◽  
Negative Binomial Distribution ◽  
Binomial Distribution ◽  
Negative Binomial ◽  
Sequential Sampling ◽  
Sampling Plan ◽  
Goodness Of Fit Test ◽  
Control Plan ◽  
Sequential Sampling Plan ◽  
Brevipalpus Phoenicis

ABSTRACT Among the pests of citrus, one of the most important is the red and black flat mite Brevipalpus phoenicis (Geijskes), which transmits the Citrus leprosis virus C (CiLV-C).When a rational pest control plan is adopted, it is important to determine the correct timing for carrying out the control plan. Making this decision demands constant follow-up of the culture through periodic sampling where knowledge about the spatial distribution of the pest is a fundamental part to improve sampling and control decisions. The objective of this work was to study the spatial distribution pattern and build a sequential sampling plan for the pest. The data used were gathered from two blocks of Valencia sweet orange on a farm in São Paulo State, Brazil, by 40 inspectors trained for the data collection. The following aggregation indices were calculated: variance/ mean ratio, Morisita index, Green’s coefficient, and k parameter of the negative binomial distribution. The data were tested for fit with Poisson and negative binomial distributions using the chi-square goodness of fit test. The sequential sampling was developed using Wald’s Sequential Probability Ratio Test and validated through simulations. We concluded that the spatial distribution of B. phoenicis is aggregated, its behavior best fitted to the negative binomial distribution and we built and validated a sequential sampling plan for control decision-making.

Economic injury level for sequential sampling plan of Frankliniella schultzei in bell pepper crops

2019 ◽  
Vol 123 ◽  
pp. 30-35 ◽  
Author(s):  
Jhersyka da S. Paes ◽  
Tamíris A. de Araújo ◽  
Rodrigo S. Ramos ◽  
João Rafael S. Soares ◽  
Vitor C.R. de Araújo ◽  
...  
Keyword(s):  
Sequential Sampling ◽  
Sampling Plan ◽  
Bell Pepper ◽  
Economic Injury Level ◽  
Frankliniella Schultzei ◽  
Sequential Sampling Plan ◽  
Economic Injury

A sequential sampling plan for exponential distribution

2016 ◽  
Vol 35 (3) ◽  
pp. 331-346
Author(s):  
Yeh Lam ◽  
Boris Choy ◽  
Philip Yu
Keyword(s):  
Exponential Distribution ◽  
Sequential Sampling ◽  
Sampling Plan ◽  
Sequential Sampling Plan

ESTIMATION OF EGG POPULATIONS OF THE CLOVER ROOT CURCULIO, SITONA HISPIDULA (COLEOPTERA: CURCULIONIDAE), IN KENTUCKY ALFALFA AND RED CLOVER FIELDS,

1977 ◽  
Vol 109 (9) ◽  
pp. 1257-1263 ◽  
Author(s):  
Y. S. Ng ◽  
M. A. Latheef ◽  
B. C. Pass
Keyword(s):  
Population Density ◽  
Red Clover ◽  
Variance Analysis ◽  
Dispersion Pattern ◽  
Sampling Techniques ◽  
Sample Unit ◽  
Margin Of Error ◽  
Clover Root ◽  
Flotation Technique ◽  
Level Of Significance

AbstractSampling techniques for estimating egg populations of the clover root curculio, Sitona hispidula (F.), were developed in alfalfa and red clover fields in Kentucky. An appropriate sample unit was a 3 × 3 in. (7.6 × 7.6 cm) area of plants and the soil beneath it to a depth of 4–5 in. (10.2–12.7 cm). This was processed by a flotation technique. The spatial disposition of the eggs conformed to a clumped pattern in both fields. The variation of 88 to 93% in log variances was accounted for by the variation in log means. There were no significant differences in dispersion pattern between the two crops. Variance analysis revealed that block and plot differences were rarely significant but the interquadrat variance predominated. The number of samples required to estimate the population with specified level of significance and margin of error was inversely proportional to population density.

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