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C.S. Vavrina, P.A. Stansly, and T.X. Liu

Household detergents were evaluated in field studies on fresh-market tomato (Lycopersicon esculentum Mill.) for insecticidal and phytotoxic effects. Laboratory bioassays were used to examine the toxicity of a household liquid dish detergent on small nymphs of silverleaf whitefly, Bemisia argentifolii Bellows and Perring. The detergents tested proved to be more toxic to whitefly nymphs than the commercial insecticidal soap. Detergent treatments were applied to tomato with a commercial high pressure hydraulic sprayer at 0%, 1%, 2%, 4%, and 8% (by volume) initially and at 0%, 0.25%, 0.5%, 1.0%, and 2.0% (by volume) in subsequent tests. As detergent rate, frequency of application, or both increased, plant dry weight accumulation and fruit yield decreased. Applying detergent also increased time to fruit maturity. A once-a-week application of 0.25% to 0.5% detergent initially applied 2 weeks after transplanting alleviated phytotoxicity and yield reduction problems.

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Erfan K. Vafaie, H. Brent Pemberton, Mengmeng Gu, David Kerns, Micky D. Eubanks, and Kevin M. Heinz

example, management of whiteflies (Aleyrodidae) on poinsettia ( Euphorbia pulcherrima ) historically has relied on regular applications of insecticides ( Palumbo et al., 2001 ; Sharaf, 1986 ; Stevens et al., 2000 ), with some growers applying

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James D. McCreight and Albert N. Kishaba

Squash leaf curl (SLC) is a virus disease of squash transmitted by the sweetpotato whitefly [Bernisia tabaci (Germ.)]. 'Cucurbita maxima Duch. ex Lam., C. mixta Pang, and C. pepo L. cultivars and the wild taxon. C. texana Gray exhibited severe symptoms in response to SLC in greenhouse and field tests. Symptoms on C. moschata (Duch.) Duch. ex Poir. cultivars were much more severe in greenhouse tests than in field tests. Three wild species, C. ecuadorensis Cutler and Whitaker, C. lundelliana Bailey, and C. martinezii Bailey, were virtually immune in greenhouse tests, but were infected in field tests. Cucurbita foetidissima HBK expressed moderate symptoms in a field test. Benincasa hispida (Thunb.) Cogn., C. ficifolia Bouche, Lagenaria siceraria (Mol.) Standl., Luffa acutangula (L.) Roxb., Luffs aegyptiaca Mill., and Luffs graveolens Roxb. were resistant to SLC in greenhouse and field tests.

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J.L. Bi and N.C. Toscano

California is a world leader in strawberry production. Since the late 1990s, strawberry production has been threatened by a major insect pest, the greenhouse whitefly, Trialeurodes vaporariorum Westwood (Homoptera: Aleyrodidae) ( Bi et al., 2002

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Gregory J. McKee, Frank G. Zalom, and Rachael E. Goodhue

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood), is a cosmopolitan pest of greenhouse crops and ornamentals. It damages plants by feeding on nutrients in a plant's phloem, which may result in yield loss ( Byrne et al., 1990 ), and

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David J. Schuster

applying treatments, counting whiteflies, and evaluating fruit. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate

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John L. Coffey, Alvin M. Simmons, B. Merle Shepard, Yaakov Tadmor, and Amnon Levi

Watermelon cultivars [ Citrullus lanatus (Thunberg) Matsum. and Nakai var. lanatus ] share a narrow genetic base ( Levi et al., 2001a ) and are susceptible to a large number of pests and diseases including whiteflies (Hemiptera: Aleyrodidae

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Cindy L. McKenzie and Joseph P. Albano

The sweetpotato whitefly has been reported in Florida since the late 1800s, but has only been considered a pest since 1986 when poinsettia ( Euphorbia pulcherrima ) growers began experiencing crop-damaging infestations ( Hamon and Salguero, 1987

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Judy G. Schmalstig and Heather J. McAuslane

Boyd for rearing the whiteflies and Karen Kelley for doing the thin sectioning, sample preparation, and photographing of the TEM sections. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations

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Robert P. Rice Jr. and Michael Crane

Twenty-four poinsettia cultivars (Euphorbia pulcherrima) were exposed to a population of greenhouse whitefly (Trialeurodes vaporariorum) and silverleaf whitefly (Bemisia argentifolii) for 6 weeks. Evaluation was based on the number of immature whitefly present on each of the marked leaves. The poinsettias that produce white bracts were more heavily infested with immature stages of whitefly than those cultivars that produce red bracts, while those that produce pink bracts were intermediate. There was a wide range in degree of whitefly infestation among poinsettia cultivars. Leaf trichome density also explained a portion of the variance in whitefly oviposition rates among several of the cultivars. Cultivars with high trichome densities sustained less whitefly oviposition than did cultivars with low trichome densities. Certain cultivars tested showed an appreciable natural resistance to whitefly (`Freedom Red', `Freedom Bright Red', `Red Velvet', `Cranberry Punch', `Pepride').