Hostname: page-component-848d4c4894-cjp7w Total loading time: 0 Render date: 2024-07-02T22:14:21.887Z Has data issue: false hasContentIssue false
  • English
  • Français

Spatial distribution of Scirtothrips aurantii Faure (Thysanoptera: Thripidae) and threshold level for one per cent. damage on citrus fruit based on trapping with fluorescent yellow sticky traps

Published online by Cambridge University Press:  10 July 2009

M. J. Samways
M. J. Samways
Affiliation:
Outspan Citrus Centre, P.O. Box 28, Nelspruit 1200, South Africa
Get access Rights & Permissions [Opens in a new window]

Abstract

The citrus pest Scirtothrips aurantii Faure shows a positive phototactic response to yellow surfaces, particularly fluorescent yellow with peak reflectance at about 525 nm. A fluorescent yellow sticky trap was devised. Impact of individuals on the trap surface was principally random. Taylor's power law gave a generalized value of 1·42 for slope of b. Widespread geographical locations gave similar values for biologically significant values of b. Habitat differences within one geographical area influenced b, which was highest in natural vegetation and lowest in certain citrus monocultures. Three traps per orchard (>5000 trees) were practicable, and produced statistically realistic results. The period during which S. aurantii can damage fruit was divided into a longer risk period and a shorter, central critical period. Where S. aurantii was present on the traps at less than nine individuals per set of three traps throughout the central critical period and 20 during the late risk period, the percentage of fruit so damaged as not to be of export grade was less than 1·0. This method of monitoring was sufficiently robust to allow for some human error in reading the traps under commercial conditions, and to permit variability in placement of the traps in the orchard.

Type
Original Articles
Information
Bulletin of Entomological Research , Volume 76 , Issue 4 , December 1986 , pp. 649 - 659
Copyright
Copyright © Cambridge University Press 1986

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anon. (1985). Colour prints for blemish and appearance standards prescribed by the export and local market regulations for citrus.—41 plates. Pretoria, S. Afr. Co-operative Citrus Exchange Ltd.Google Scholar
Bedford, E. C. G. (1943). The biology and economic importance of the South African citrus thrips, Scirtothrips aurantii Faure.—Publs Univ. Pretoria (Nat. Sci.) no. 7, 68 pp.Google Scholar
Elliot, J. M. (1977). Some methods for the statistical analysis of samples of benthic invertebrates.—2nd edn, 160 pp. Windermere, UK, Freshwater Biol. Ass.Google Scholar
Georgala, M. B. (1982). Thrips control: comments on registered treatments.—Citrus & Subtropical Fruit Journal no. 585, 13, 14, 16, 17, 19.Google Scholar
Hall, W. J. (1930). The South African citrus thrips in Southern Rhodesia.—Publs Br. S. Afr. Co. no. 1, 56 pp.Google Scholar
Jones, V. P. & Parrella, M. P. (1984). Dispersion indices and sequential sampling plans for the citrus red mite (Acari: Tetranychidae).—J. econ. Ent. 77, 75–79.CrossRefGoogle Scholar
Reed, D. K. & Rich, J. R. (1975). A new survey technique for citrus thrips.—J. econ. Ent. 68, 739–742.CrossRefGoogle Scholar
Samways, M. J. (1984). Use of Saturn Yellow traps for monitoring Trioza erytreae (Hemiptera: Triozidae) and an attempt at commercial suppression using yellow barriers and trap trees.—pp. 72–83 in Unpublished Proceedings of a Symposium on Citrus Greening held at the Citrus and Subtropical Fruit Research Institute, 26–28 11, 1984.—201 pp. Nelspruit, South Africa, Agric. and Water Supply (C.S.F.R.I.).Google Scholar
Samways, M. J. (1985). Initial development of a fluorescent yellow trap for monitoring a complex of citrus insects.—pp. 36–37 in Proceedings of the 5th Entomological Congress organized by the Entomological Society of Southern Africa, Grahamstown, 2–4 06 1985.—48 pp. Pretoria, Entomological Society of Southern Africa.Google Scholar
Samways, M. J. (1986). Spatial and temporal population patterns of Aonidiella aurantii (Maskell) (Hemiptera: Diaspididae) parasitoids (Hymenoptera: Aphelinidae and Encyrtidae) caught on yellow sticky traps in citrus.—Bull. ent. Res. 76, 265–274.CrossRefGoogle Scholar
Siegel, S. (1956). Non-parametric statistics for the behavioral sciences.—312 pp. New York, McGraw-Hill.Google Scholar
Taylor, L. R. (1984). Assessing and interpreting the spatial distributions of insect populations.—A. Rev. Ent. 29, 321–357.CrossRefGoogle Scholar
Taylor, L. R., Woiwod, I. P. & Perry, J. N. (1980). Variance and the large scale spatial stability of aphids, moths and birds.—J. Anim. Ecol. 49, 831–854.CrossRefGoogle Scholar
Wentzel, P. C., Georgala, M. B. & Bedford, E. C. G. (1978). Citrus thrips, Scirtothrips aurantii Faure.—pp. 137–141 in Bedford, E. C. G. (Ed.). Citrus pests in the Republic of South Africa.—253 pp. Pretoria, Dep. Agric. Tech. Serv.Google Scholar