Sampling Methods, Dispersion Patterns, and Fixed Precision Sequential Sampling Plans for Western Flower Thrips (Thysanoptera: Thripidae) and Cotton Fleahoppers (Hemiptera: Miridae) in Cotton

2006 ◽  
Vol 99 (2) ◽  
pp. 568-577 ◽  
Author(s):  
M. N. Parajulee ◽  
R. B. Shrestha ◽  
J. F. Leser
Keyword(s):  
Sampling Methods ◽  
Sequential Sampling ◽  
Western Flower Thrips ◽  
Sampling Plans ◽  
Flower Thrips ◽  
Dispersion Patterns

MONITORING WESTERN FLOWER THRIPS (THYSANOPTERA: THRIPIDAE) IN “GRANNY SMITH” APPLE BLOSSOM CLUSTERS

1988 ◽  
Vol 120 (11) ◽  
pp. 1003-1016 ◽  
Author(s):  
L. Irene Terry ◽  
Gloria DeGrandi-Hoffman
Keyword(s):  
Variance Component ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Extraction Process ◽  
Regression Coefficients ◽  
Sampling Plans ◽  
Flower Thrips ◽  
Precision Level ◽  
Cluster Type ◽  
Over Time

AbstractThe efficiency and accuracy of sampling western flower thrips (Frankliniella occidentalis [Pergande]) from “Granny Smith” apple blossom clusters were analyzed during 1986–1987 to develop a sampling plan for research purposes. The accuracy of the “shake” method was compared with an “extraction” process of each of three blossom cluster types: pink, open, and petalless (petal fall). Thrip extractions from combined clusters revealed that a 9-s and 6-s “shake” removed 84 and 74%, of the thrips, respectively, but a 3-s “shake” removed 53%, and was more variable. Open blossom clusters always had higher thrips densities than either pink or petal fall clusters, regardless of the bloom state. The effects of cardinal position within trees were not consistent over time. Clusters from the top of the canopy had more thrips than lower canopy clusters, and apical clusters had more thrips than basal clusters during peak bloom. Variance component analyses indicated that thrips counts from clusters within tree were more variable than counts among trees, even when cluster types were analyzed separately. Two sets of indices (Iwao’s regression of mean crowding on mean density and Taylor’s regression of log variance on log mean density) for each cluster type indicated aggregated spatial patterns. Precision level sampling plans were developed using Iwao’s regression coefficients.

scholarly journals Sequential and Binomial Sampling Plans to Estimate Thrips tabaci Population Density on Onion

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 331
Author(s):  
Lauro Soto-Rojas ◽  
Esteban Rodríguez-Leyva ◽  
Néstor Bautista-Martínez ◽  
Isabel Ruíz-Galván ◽  
Daniel García-Palacios
Keyword(s):  
Sampling Methods ◽  
Sequential Sampling ◽  
Thrips Tabaci ◽  
Economic Losses ◽  
Management Approach ◽  
Data Sets ◽  
Sampling Plans ◽  
Binomial Sampling ◽  
Population Sampling ◽  
Use Of Time

Thrips tabaci Lindeman is a worldwide onion pest that causes economic losses of 10–60%, depending on many factors. Population sampling is essential for applying control tactics and preventing damage by the insect. Conventional sampling methods are criticized as time consuming, while fixed-precision binomial and sequential sampling plans may allow reliable estimations with a more efficient use of time. The aim of this work was to develop binomial and sequential sampling for fast reliable estimation of T. tabaci density on an onion. Forty-one commercial 1.0-ha onion plots were sampled (sample size n = 200) to characterize the spatial distribution of T. tabaci using Taylor’s power law (a = 2.586 and b = 1.511). Binomial and sequential enumerative sampling plans were then developed with precision levels of 0.10, 0.15 and 0.25. Sampling plans were validated with bootstrap simulations (1000 samples) using 10 independent data sets. Bootstrap simulation indicated that precision was satisfactory for all repetitions of the sequential sampling plan, while binomial sampling met the fixed precision in 80% of cases. Both methods reduced sampling time by around 80% relative to conventional sampling. These precise and less time-consuming sampling methods can contribute to implementation of control tactics within the integrated pest management approach.

SPATIAL PATTERNS OF AND SAMPLING METHODS FOR WESTERN FLOWER THRIPS (THYSANOPTERA: THRIPIDAE) ON GREENHOUSE SWEET PEPPER

1991 ◽  
Vol 123 (5) ◽  
pp. 989-1000 ◽  
Author(s):  
J.L. Shipp ◽  
N. Zariffa
Keyword(s):  
Spatial Patterns ◽  
Sampling Method ◽  
Sampling Methods ◽  
Western Flower Thrips ◽  
Sweet Pepper ◽  
Pepper Plant ◽  
Individual Plant ◽  
Flower Thrips ◽  
Precision Level ◽  
Plant Spatial Patterns

AbstractIntra- and inter-plant spatial patterns were determined for adult and immature western flower thrips, Frankliniella occidentalis (Pergande), on greenhouse sweet pepper at two commercial greenhouses using five sampling methods. The population density of the thrips was monitored biweekly for 4 months from May to August using blue sticky-traps, plant tappings, blossoms, plant leaves, and whole plants. The intra-plant spatial patterns of adult and immature populations of F. occidentalis were aggregated with the majority of the thrips collected from the top one-third of the plant. The inter-plant spatial patterns also were aggregated. The aggregation cluster for the adult thrips was at least three plants in size, although it was surmised to be at the individual plant level for immature F. occidentalis. The accuracy of the blue sticky-trap, plant tapping, blossom, and leaf samples was determined for monitoring the population densities of adult and immature thrips throughout the growing season. It was shown that leaves should be sampled from the middle section of the sweet pepper plant when using this sampling method. A precision-level sampling program was proposed for monitoring adult F. occidentalis on greenhouse sweet pepper. Sampling blossoms was the most cost-effective sampling method based upon time and number of samples for a specific precision level.

scholarly journals Morphological and Chemical Factors Related to Western Flower Thrips Resistance in the Ornamental Gladiolus

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1384
Author(s):  
Dinar S. C. Wahyuni ◽  
Young Hae Choi ◽  
Kirsten A. Leiss ◽  
Peter G. L. Klinkhamer
Keyword(s):  
Host Plant ◽  
Plant Resistance ◽  
Host Plant Resistance ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Resistance Breeding ◽  
Breeding Programs ◽  
Triterpenoid Saponins ◽  
Flower Thrips ◽  
Highly Correlated

Understanding the mechanisms involved in host plant resistance opens the way for improved resistance breeding programs by using the traits involved as markers. Pest management is a major problem in cultivation of ornamentals. Gladiolus (Gladiolus hybridus L.) is an economically important ornamental in the Netherlands. Gladiolus is especially sensitive to attack by western flower thrips (Frankliniella occidentalis (Pergande) (Thysanoptera:Thripidae)). The objective of this study was, therefore, to investigate morphological and chemical markers for resistance breeding to western flower thrips in Gladiolus varieties. We measured thrips damage of 14 Gladiolus varieties in a whole-plant thrips bioassay and related this to morphological traits with a focus on papillae density. Moreover, we studied chemical host plant resistance to using an eco-metabolomic approach comparing the 1H NMR profiles of thrips resistant and susceptible varieties representing a broad range of papillae densities. Thrips damage varied strongly among varieties: the most susceptible variety showed 130 times more damage than the most resistant one. Varieties with low thrips damage had shorter mesophylls and epidermal cells, as well as a higher density of epicuticular papillae. All three traits related to thrips damage were highly correlated with each other. We observed a number of metabolites related to resistance against thrips: two unidentified triterpenoid saponins and the amino acids alanine and threonine. All these compounds were highly correlated amongst each other as well as to the density of papillae. These correlations suggest that papillae are involved in resistance to thrips by producing and/or storing compounds causing thrips resistance. Although it is not possible to distinguish the individual effects of morphological and chemical traits statistically, our results show that papillae density is an easy marker in Gladiolus-breeding programs targeted at increased resistance to thrips.

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