HortScience (2005) 40, 691-693

C.A. Powell, R.R. Pelosi, M.S. Burton, P.A. Rundell, M.A. Ritenour and R.C. Bullock (2005)
Natural field spread of decline and nondecline inducing isolates of Citrus tristeza virus in Florida after the introduction of the brown citrus aphid
HortScience 40 (3), 691-693
Abstract: The effectiveness of seven different aphid control regimes in delaying movement of decline (DI) and nondecline (NDI) inducing isolates of citrus tristeza virus (CTV) into a CTV-free sweet orange scion on sour orange rootstock block was monitored annually for 5 years beginning in 1999, 2 years after the introduction of the brown citrus aphid (BrCA) into the region. After 5 years, the mean percentages of infection with DI CTV were 19, 19, 17, 29, 23, 19, or 14 for trees treated annually with imidocloprid, every 6 months with imidocloprid, every 3 months with imidocloprid, every 2 months with imidocloprid, annually with Temik, annually with Meta Systox-R, or untreated, respectively. The mean percentages of infection (after 5 years) with only NDI isolates of CTV for the seven treatments were 40, 31, 33, 38, 38, 38, or 33. There was no significant difference (after 5 years) among either the DI or NDI CTV treatment means. The overall 5-year infection percentage for DI CTV (20%) was somewhat lower than that reported before the introduction of the BrCA (27%) (11). Aphid densities (Toxoptera citricidus and Aphis spiraecola) varied considerably from year to year. Good aphid control was achieved with all four imidocloprid treatments, but not with Temik or Meta Systox-R. The level of aphid control did not influence overall CTV infection percentages.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

Research topic(s) for pests/diseases/weeds:
transmission/dispersal of plant diseases
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aphis citricidus	Citrus (genus)	U.S.A. (SE)
	Citrus tristeza virus	Citrus (genus)	U.S.A. (SE)
	Aphis spiraecola	Citrus (genus)	U.S.A. (SE)