Fixed-Precision Sequential Sampling Plans for Estimating Alfalfa Caterpillar,<i>Colias lesbia</i>, Egg Density in Alfalfa,<i>Medicago sativa</i>, Fields in Córdoba, Argentina

Serra, Gerardo; Porta, Norma C. La; Ávalos, Susana Valencia; Mazzuferi, V.

doi:10.1673/031.013.4101

Cited by 7 publications

(6 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…(Lepidoptera: Pieridae). Se trata de la principal plaga de la alfalfa (Serra et al, 2013), leguminosa cultivada en el predio donde realizamos la plantación. El tala fue levemente más afectado, posiblemente a causa de mayor área foliar efectiva con respecto al algarrobo (tala 409.6 mm 2 vs algarrobo 25.2 mm 2 ) (Zeballos et al, 2014).…”

Section: Discussionunclassified

Reforestar en áreas agrícola-ganaderas: un estudio de caso evaluando el desempeño de dos especies nativas del Espinal

Cappri

Torres

Estrabou

2020

Bol. Soc. Argent. Bot.

View full text Add to dashboard Cite

Introducción y objetivos: La restauración de bosques es un tema de interés creciente, especialmente en zonas agrícola-ganaderas donde los parches remanentes de bosque nativo son escasos. Evaluamos el desempeño de plantines de dos especies arbóreas nativas del Espinal. Nos propusimos (1) comparar la supervivencia y el crecimiento de plantines de Prosopis alba (algarrobo blanco) y Celtis ehrenbergiana (tala) plantados en un sitio al borde del bosque y en un sitio abierto, (2) comparar la incidencia de herbívoros entre especies y sitios, (3) describir otros factores ambientales que pudieran afectar el desempeño de los plantines en el contexto agrícola-ganadero. M&M: Plantamos 200 plantines por especie, distribuidos en los dos sitios y evaluamos mensualmente la supervivencia, altura e incidencia de herbívoros. Resultados: A los 11 meses, la supervivencia de algarrobo y tala fue de 32% y 17%, respectivamente (P<0,0001). El algarrobo tuvo mayor supervivencia en el borde del bosque mientras el tala tuvo mayor supervivencia en el sitio abierto (interacción sitio x especie, P<0,0001). La altura final fue menor que al momento de la plantación, sin diferencias entre especies ni sitios (P>0,05). Los herbívoros vertebrados afectaron al 28% de los plantines de ambas especies, mientras que los invertebrados afectaron en promedio un 5% de los plantines. Durante el experimento la plantación fue afectada por la deriva de herbicidas. Conclusiones: Recomendamos la plantación de algarrobo para extender parches de bosque remanentes y de tala para la creación de nuevos parches en sitios abiertos o incrementar conexión entre parches aislados, con exclusión ganadera y en sitios que estén protegidos de la deriva de herbicidas.

show abstract

Section: Discussionunclassified

Reforestar en áreas agrícola-ganaderas: un estudio de caso evaluando el desempeño de dos especies nativas del Espinal

Cappri

Torres

Estrabou

2020

Bol. Soc. Argent. Bot.

View full text Add to dashboard Cite

show abstract

“…where T n is the critical cumulative count over n samples (number of larvae or damaged fruit), a and b are the estimated parameters in model (1a), and D is the desired level of precision (Serra et al, 2013). Kuno's (1969) fi xed-precision sampling algorithm uses the parameters of Iwao's patchiness model (2) based on Lloyd's mean crowding index m*.…”

Section: Minimum Number Of Samples and Plans For Fi Xed Precision Seqmentioning

confidence: 99%

“…In order to ensure that T n remains positive in Kuno's plan n > (b -1) / D 2 (Naranjo & Hutchison, 1997). In population dynamics studies, a precision level of 0.10 is usually suggested (Southwood, 1978), while for decision making in pest management a precision level of 0.20 or 0.25 is preferred (Serra et al, 2013). In the current survey, three precision levels D = 0.10, 0.15 or 0.20 were chosen to develop plans for sampling that cover most circumstances.…”

Section: Minimum Number Of Samples and Plans For Fi Xed Precision Seqmentioning

confidence: 99%

“…A minimal number of fi ve samples was used for all the simulations along with the fi xed precision levels of 0.10, 015 or 0.20. Resampling was run 500 times for each data set, which is satisfactory in most cases (Naranjo & Hutchison, 1997) in order to calculate the average, minimum and maximum precision levels, and sample sizes (Serra et al, 2013). Resampling was done using the RVSP V. 2 excel add-on freely available from the United States Department of Agriculture (Naranjo & Hutchinson, 2016).…”

Section: Validation Of the Plans For The Fi Xed Sequential Resamplingmentioning

confidence: 99%

See 1 more Smart Citation

Density-invariant dispersion indices and fixed precision sequential sampling plans for the peach twig borer Anarsia lineatella (Lepidoptera: Gelechiidae)

Damos¹

2018

Eur. J. Entomol.

View full text Add to dashboard Cite

Estimating the spatial dispersion of pest arthropods is crucial for the development of reliable sampling programs and one of the main components of integrated pest management. The natural spatial distribution of a population of a species may be random, uniform, or aggregated and can be so classifi ed based on calculation of variance to mean relations and related dispersion indices. In this work some classical density-invariant dispersion indices and related regression models are used for the fi rst time to quantify the spatial dispersion of an important peach pest Anarsia lineatella Zeller (Lepidoptera: Gelechiidae) and construct fi xed precision sequential sampling schemes. Taylor's power law, Iwao's patchiness regression and Nachman's model were used to analyse the damage to peaches caused by A. lineatella. All three regression models fi t the data well, although the results indicate that Iwao's patchiness model provides a better description of the relationship between variance and mean density. Taylor's b and Iwao's b regression indices were both signifi cantly smaller than 1, indicating that the distribution of individuals was uniform rather than random or aggregated. According to Green's and Kuno's models, the minimum sample size at the precision level of 0.2 varies from 3 samples, when total population density is more than 3 larvae/sample, to 10 samples, when population density is between 1 and 2 larvae/sample. Kuno's fi xed sampling plan indicates that a small number of samples (i.e., 3-10 branches with fruit) is suffi cient to estimate the mean population density of A. lineatella larvae with a precision of 0.2. The Resampling for validation of sampling plans (RVSP) method confi rmed that the average level of precision of the fi xed sequential plans matched the desired precision in most cases. The sampling plan presented here provides a level understanding of A. lineatella spatial ecology suitable for pest management decisions.

show abstract

“…Pedigo (1993) emphasized that the absence of cost-effective, user-friendly sampling plans for arthropod pests in food crops is a major impediment to the adoption of IPM. Several studies have demonstrated that deployment of reliable and practically feasible sampling plans may lead to reduction in pesticide applications and improved pest management (Sylvester and Cox 1961, Giles et al 2000, Butler and Trumble 2012, Martini et al 2012, Serra et al 2013, Stubbins et al 2014. Within a sampling plan, the sampling technique, unit, and pattern must be defined, and the accuracy and efficiency must be addressed, which are often competing needs (Landis 1993, Pedigo 1993.…”

mentioning

confidence: 99%

Spatially-Optimized Sequential Sampling Plan for Cabbage AphidsBrevicoryne brassicaeL. (Hemiptera: Aphididae) in Canola Fields

2016

View full text Add to dashboard Cite

The cabbage aphid is a significant pest worldwide in brassica crops, including canola. This pest has shown considerable ability to develop resistance to insecticides, so these should only be applied on a "when and where needed" basis. Thus, optimized sampling plans to accurately assess cabbage aphid densities are critically important to determine the potential need for pesticide applications. In this study, we developed a spatially optimized binomial sequential sampling plan for cabbage aphids in canola fields. Based on five sampled canola fields, sampling plans were developed using 0.1, 0.2, and 0.3 proportions of plants infested as action thresholds. Average sample numbers required to make a decision ranged from 10 to 25 plants. Decreasing acceptable error from 10 to 5% was not considered practically feasible, as it substantially increased the number of samples required to reach a decision. We determined the relationship between the proportions of canola plants infested and cabbage aphid densities per plant, and proposed a spatially optimized sequential sampling plan for cabbage aphids in canola fields, in which spatial features (i.e., edge effects) and optimization of sampling effort (i.e., sequential sampling) are combined. Two forms of stratification were performed to reduce spatial variability caused by edge effects and large field sizes. Spatially optimized sampling, starting at the edge of fields, reduced spatial variability and therefore increased the accuracy of infested plant density estimates. The proposed spatially optimized sampling plan may be used to spatially target insecticide applications, resulting in cost savings, insecticide resistance mitigation, conservation of natural enemies, and reduced environmental impact.

show abstract

Fixed-Precision Sequential Sampling Plans for Estimating Alfalfa Caterpillar,Colias lesbia, Egg Density in Alfalfa,Medicago sativa, Fields in Córdoba, Argentina

Cited by 7 publications

References 16 publications

Reforestar en áreas agrícola-ganaderas: un estudio de caso evaluando el desempeño de dos especies nativas del Espinal

Reforestar en áreas agrícola-ganaderas: un estudio de caso evaluando el desempeño de dos especies nativas del Espinal

Density-invariant dispersion indices and fixed precision sequential sampling plans for the peach twig borer Anarsia lineatella (Lepidoptera: Gelechiidae)

Spatially-Optimized Sequential Sampling Plan for Cabbage AphidsBrevicoryne brassicaeL. (Hemiptera: Aphididae) in Canola Fields

Contact Info

Product

Resources

About