Effect of kaolin clay on migrant alate aphids (Hemiptera: Aphididae) in blueberry fields in the context of Blueberry scorch virus

D. A. Raworth, S. Mathur, M. G. Bernardy, C. J. French, M. Chatterton, C.-K. Chan, R. G. Foottit, E. Maw


The efficacy of kaolin clay (Surround® WP) in reducing the number of migrant aphids on blueberry, Vaccinium corymbosum L. (Ericaceae) and the incidence of Blueberry scorch virus (BlScV) was determined. Two applications of kaolin clay reduced the number of alatae collected on treated ‘Berkeley’ plants by as much as a factor of eight between 4 June and 16 August. However, five of 100 test plants located near infected fields and exposed only to migrant alatae between 10 May and 16 August became infected with BlScV: three controls and two treated with kaolin clay. The work demonstrates the importance of migrant alatae in the spread of BlScV; 5% transmission is consistent with previous estimates of annual virus spread by winged and non-winged aphids. Three of the plants became infected between 10 and 27 May (one control and two treated with kaolin clay), indicating the importance of aphid flights in May for virus transmission. Rainfall removed much of the kaolin clay and this may have affected its efficacy. The aphid data demonstrated that migrant alatae are able to discriminate between untreated and kaolin—treated blueberry plants, and that Ericaphis fimbriata (Richards), which utilizes blueberry as a host, discriminates better than other migrant species. Water trap data do not necessarily reflect the total migrant aphid composition found on plants in the field. Plant growth was not affected by the kaolin clay, but the fruit had clay residues amongst the bracts of the calyx limiting the use of this product on producing fields to the period before fruit set. Kaolin clay may be best suited to protection of nursery stock, but further work is needed to improve efficacy during wet weather and determine optimal application frequency.

Note: Use of trade names or trademarks does not imply endorsement of the companies or products named nor criticism of similar ones not named.


Ericaphis fimbriata; aphid behaviour; virus transmission

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Bernardy, M.G., C.R. Dubeau, A. Braun, C.E. Harlton, A. Bunckle, L.A. Wegener, D.T. Lowery, and C.J. French. 2005. Molecular characterization and phylogenetic analysis of two distinct strains of Blueberry scorch virus from western Canada. Canadian Journal of Plant Pathology 27: 581-591.

Bristow, P.R., R.R. Martin, and G.E. Windom. 2000. Transmission, field spread, cultivar response, and impact on yield in highbush blueberry infected with Blueberry scorch virus. Phytopathology 90: 474-479.

Chan, C.K. and B.D. Frazer. 1993. The aphids (Homoptera: Aphididae) of British Columbia 21. Further additions. Journal of the Entomological Society of British Columbia 90: 77-82.

Clark, M.F. and A.N. Adams. 1977. Characteristics of the microplate method of ELISA for the detection of plant viruses. Journal General Virology 34: 475-483.

Lees A.D. 1961. Clonal polymorphism in aphids, pp. 68-79. In J.S. Kennedy (Ed.), Insect Polymorphism. Royal Entomological Society, London.

Liang, G. and T.-X. Liu. 2002. Repellency of a kaolin particle film, Surround, and a mineral oil, Sunspray oil, to silverleaf whitefly (Homoptera: Aleyrodidae) on melon in the laboratory. Journal of Economic Entomology 95: 317-324.

Lowery, D.T., M.K. Sears, and C.S. Harmer. 1990. Control of turnip mosaic virus of rutabaga with applications of oil, whitewash, and insecticides. Journal of Economic Entomology 83: 2352-2356.

Martin, R.R. and P.R. Bristow. 1988. A carlavirus associated with blueberry scorch disease. Phytopathology 78: 1636-1640.

Pataky, J.K., C.C. Block, P.M. Michener, L.M. Shepherd, D.C. McGee, and D.G. White. 2004. Ability of an ELISA-based seed health test to detect Erwinia stewartii in maize seed treated with fungicides and insecticides. Plant Disease 88: 633-640.

Raworth, D.A. 2004. Ecology and management of Ericaphis fimbriata (Hemiptera: Aphididae) in relation to the potential for spread of Blueberry scorch virus. The Canadian Entomologist 136: 711-718.

Raworth D.A. and D. Schade. 2006. Life history parameters and population dynamics of Ericaphis fimbriata (Hemiptera: Aphididae) on blueberry, Vaccinium corymbosum. The Canadian Entomologist 138: 205-217.

Raworth, D.A., C.-K. Chan, R.G. Foottit, and E. Maw. 2006. Spatial and temporal distribution of winged aphids (Hemiptera: Aphididae) frequenting blueberry fields in southwestern British Columbia and implications for the spread of Blueberry scorch virus. The Canadian Entomologist 138: 104-113.

Remaudière, G. and M. Remaudière. 1997. Catalogue of the World’s Aphididae. INRA, Paris.

Rowhani, A., L. Biardi, R. Johnson, P. Saldarelli, Y.P. Zhang, J. Chin, and M. Green. 2000. Simplified sample preparation method and one tube RT-PCR for grapevine viruses, p. 148. In M. Fuchs and S. Grenan (Eds.), Proceedings of the 13th Congress of the International Council for Viruses and Virus-like Diseases of the Grapevine, Adelaide, Australia, 12-17 March 2000. University of Adelaide and Commonwealth Scientific and Industrial Research Organization (CSIRO), Adelaide, Australia.

SAS Institute Inc. 1990. SAS/STAT user’s guide, Version 6. SAS Institute Inc., Cary, North Carolina.

Southwood, T.R.E. 1966. Ecological methods with particular reference to the study of insect populations. Methuen & Co., London.

Spiers, J.D., F.B. Matta, D.A. Marshall, and B.J. Sampson. 2004. Effects of kaolin clay application on flower bud development, fruit quality and yield, and flower thrips [Frankliniella spp. (Thysanoptera: Thripidae)] populations of blueberry plants, pp. 361-373. In C.F. Forney and L.J. Eaton (Eds.), Proceedings of the Ninth North American Blueberry Research and Extension Workers Conference. Haworth Press, Inc., Binghamton, New York.

Sutula, C.L., J.M. Gillett, S.M. Morrissey, and D.C. Ramsdell. 1986. Interpreting ELISA data and establishing the positive-negative threshold. Plant Disease 70: 722-726.

Wegener, L.A., R.R. Martin, M.G. Bernardy, L. MacDonald, and Z.K. Punja. 2006. Epidemiology and identification of strains of Blueberry scorch virus on highbush blueberry in British Columbia, Canada. Canadian Journal of Plant Pathology 28: 250-262.


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