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

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.

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Development of Binomial Sequential Sampling Plans for Sugarcane Aphid (Hemiptera: Aphididae) in Commercial Grain Sorghum

Journal of Economic Entomology ◽

10.1093/jee/toaa064 ◽

2020 ◽

Vol 113 (4) ◽

pp. 1990-1998 ◽

Cited By ~ 1

Author(s):

Jessica C Lindenmayer ◽

Kristopher L Giles ◽

Norman C Elliott ◽

Allen E Knutson ◽

Robert Bowling ◽

...

Keyword(s):

Goodness Of Fit ◽

Sequential Sampling ◽

Grain Sorghum ◽

Ratio Test ◽

Test Model ◽

Leaf Sample ◽

Melanaphis Sacchari ◽

Sampling Plans ◽

Sugarcane Aphid ◽

Economic Thresholds

Abstract The sugarcane aphid (Melanaphis sacchari Zehntner) is a significant economic pest of grain sorghum (Sorghum bicolor (L.) Moench) in the Southern United States. Current nominal and research-based economic thresholds are based on estimates of mean aphids per leaf. Because enumerating aphids per leaf is potentially time consuming, binomial sequential sampling plans for M. sacchari were developed that allow users to quickly classify the economic status of field populations and determine when an economic threshold has been exceeded. During 2016 and 2017, counts of M. sacchari were recorded from 281 sampling events in 140 sorghum fields located in six states (Oklahoma, Kansas, Texas, Arkansas, Louisiana, Mississippi) . Regression analysis was used to describe the relationships between the mean M. sacchari density per two-leaf sample and proportion of plants infested with one or more aphids. Tally thresholds of T50 and T100 aphids per two-leaf sample were selected based on goodness of fit and practicality. Stop lines for both tally thresholds were developed for selected economic thresholds using Wald’s sequential probability ratio test. Model validations using an additional 48 fields demonstrated that reliable classification decisions could be made with an average of 11 samples regardless of location. This sampling system, when adopted, can allow users to easily and rapidly determine when M. sacchari infestations need to be treated.

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Sequential Sampling Plan for Aphis gossypii (Hemiptera: Aphididae) based on Its Intra-plant Distribution Patterns in Greenhouse Cucumber at Different Growth Stages

Korean journal of applied entomology ◽

10.5656/ksae.2015.10.0.046 ◽

2015 ◽

pp. 401-407

Author(s):

Bu-Keun Chung ◽

◽

Jeong-Heub Song ◽

Heung-Su Lee ◽

Byeong-Ryul Choi

Keyword(s):

Sequential Sampling ◽

Aphis Gossypii ◽

Distribution Patterns ◽

Sampling Plan ◽

Plant Distribution ◽

Growth Stages ◽

Sequential Sampling Plan ◽

Greenhouse Cucumber ◽

Different Growth Stages ◽

Plant Distribution Patterns

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Risk Assessment for Tomato Fruitworm in Processing Tomato Crop-Egg Location and Sequential Sampling

Insects ◽

10.3390/insects12010013 ◽

2020 ◽

Vol 12 (1) ◽

pp. 13

Author(s):

Elisabete Figueiredo ◽

Catarina Gonçalves ◽

Sónia Duarte ◽

Maria C. Godinho ◽

António Mexia ◽

...

Keyword(s):

Spatial Pattern ◽

Sequential Sampling ◽

Sampling Plan ◽

Random Pattern ◽

Growth Stages ◽

Data Sets ◽

Tomato Crop ◽

Sample Number ◽

Sequential Sampling Plan ◽

Fixed Sample

Helicoverpa armigera is one of the key pests affecting processing tomatoes and many other crops. A three-year study was conducted to describe the oviposition preferences of this species on determinate tomato plants (mainly the stratum, leaf, leaflet, and leaf side) and the spatial pattern of the eggs in the field, to form a sequential sampling plan. Eggs were found mainly in the exposed canopy, on leaves a (upper stratum) and b (upper-middle stratum) and significantly fewer eggs on leaf c (middle-lower stratum) below flower clusters. This vertical pattern in the plant was found in all phenological growth stages. The spatial pattern was found to be aggregated, with a trend towards a random pattern at lower densities. A sequential sampling plan was developed, based on Iwao’s method with the parameters of Taylor’s power law, with minimum and maximum sample size of 20 and 80 sample units (plants), respectively (two leaves/plant). For its validation, operating characteristic (OC) and average sample number (ASN) curves were calculated by means of simulation with independent data sets. The β-error was higher than desirable in the vicinity of the economic threshold, but this sampling plan is regarded as an improvement both in effort and precision, compared with the fixed sample plan, and further improvements are discussed.

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

The Canadian Entomologist ◽

10.4039/ent120497-6 ◽

1988 ◽

Vol 120 (6) ◽

pp. 497-505 ◽

Cited By ~ 22

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.

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A Fixed-Precision Sequential Sampling Plan for the Potato Tuberworm Moth, Phthorimaea operculella Zeller (Lepidoptera: Gelechidae), on Potato Cultivars

Neotropical Entomology ◽

10.1007/s13744-017-0487-1 ◽

2017 ◽

Vol 46 (4) ◽

pp. 388-395 ◽

Cited By ~ 4

Author(s):

M Shahbi ◽

A Rajabpour

Keyword(s):

Sequential Sampling ◽

Sampling Plan ◽

Potato Cultivars ◽

Phthorimaea Operculella ◽

Sequential Sampling Plan ◽

Potato Tuberworm Moth ◽

Potato Tuberworm

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

10.31220/agrirxiv.2020.00011 ◽

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).

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Analysis and Design of the Sequential Sampling Plan by Attributes Based on the Minimal Lattice Paths

Frontiers in Statistical Quality Control ◽

10.1007/978-3-662-11787-3_4 ◽

1987 ◽

pp. 52-66

Author(s):

H. Ohta ◽

M. Furukawa

Keyword(s):

Sequential Sampling ◽

Sampling Plan ◽

Lattice Paths ◽

Analysis And Design ◽

Sequential Sampling Plan ◽

Minimal Lattice

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SPATIAL DISTRIBUTION AND SEQUENTIAL SAMPLING OF Brevipalpus phoenicis IN CITRUS

Revista Brasileira de Fruticultura ◽

10.1590/0100-29452016085 ◽

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.

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