Journal of Economic Entomology (1995) 88, 1658-1665

Kijong Cho, Craig S. Eckel, James F. Walgenbach and George G. Kennedy (1995)
Spatial distribution and sampling procedures for Frankliniella spp. (Thysanoptera: Thripidae) in staked tomato
Journal of Economic Entomology 88 (6), 1658-1665
Abstract: Phytophagous thrips were sampled in commercial tomato, Lycopersicum esculentum L., fields in western North Carolina during a 3-yr period from 1990 to 1992. Tomato flowers were collected to sample thrips and evaluate 3 different sampling units (2, 5, and 10 flowers) for their relative net precision. Flower thrips, Frankliniella tritici (Fitch), and western flower thrips, Frankliniella occidentalis (Pergande), were the dominant species collected, accounting for 96% of all specimens. Relative net precision values indicated that a 10-flower unit was more precise and cost-efficient than either the 2- or 5-flower unit. Frequency data collected from the 10-flower unit were described by the negative binomial distribution. Both F. occidentalis and F. tritici exhibited an aggregated distribution in tomato fields. Taylor power law provided a better fit to the data than Iwao patchiness regression. Slopes and intercepts of Taylor power law did not differ among thrips species or total thrips. A fixed-precision-level sequential sampling plan was developed using the parameters of Taylor power law generated from total number of thrips in a 10-flower sampling unit. The resulting sampling plan was tested with sequential sampling bootstrap simulations (n = 500) using 11 independent data sets for the validation. Bootstrap simulation over a range of densities demonstrated that actual D_o values at D_o = 0.30 averaged <0.26 in every case.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): James F. Walgenbach, George G. Kennedy, Kijong Cho

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Frankliniella occidentalis	Tomato (Solanum lycopersicum)	U.S.A. (SE)
	Frankliniella tritici	Tomato (Solanum lycopersicum)	U.S.A. (SE)