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Rosalía Servín, Jos L. Martínez, E. Troyo-Diguez, and A. Ortega

The sweetpotato whitefly [Bemisia tabaci (Gennadius)] has become a high-risk insect pest in Mexico as well as in other countries, causing serious damage to several crops. Control of whitefly in Baja California Sur, ,Mexico, is usually done by intense insecticides applications, either alone or in mixtures of several kinds. The aim in this work was to determine its susceptibility to cypermethrin, endosulfan, methamidophos, and methyl-parathion. LC50 was obtained to identify the resistant and susceptible populations. A group of 20 whiteflies were introduced in a 20-ml scintillation vial coated in the inner surface with a known concentration of the insecticide. Mortality readings were obtained 3 h after exposing the insects to the residual activity at five concentrations. Five replications and control were run in different consecutive days for each bioassay. Results indicated that cypermethrin was the most toxic to B. tabaci and metamidophos the least. Data will be considered for further evaluations.

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Chang-chi Chu*, Kai Umeda, Tian-Ye Chen, Alvin M. Simmons, and Thomas H. Henneberry

Insect traps are vital component of many entomological programs for detection and monitoring of insect populations. We equipped yellow (YC), blue (BC) sticky card (BC) with 530 nm lime green (LED-YC) and 470 nm blue (LED-BC) light-emitting diodes, respectively that increased trap catches of several insect pests. The LED-YC traps caught 1.3, 1.4, 1.8, and 4.8 times more adult greenhouse whitefly Trialeurodes vaporariorum (Westwood), sweetpotato whitefly Bemisia tabaci (Gennadius) biotype B, cotton aphids Gossypium hirsutum (L.), and fungus gnats Bradysia coprophila (Lintner), respectively, compared with standard YC traps. The LED-YC traps did not catch more Eretmocerus spp. than the standard YC traps. Eretmocerus spp. are important B. tabaci parasitoids used in greenhouse biological control programs. For whitefly control in greenhouse the 530 nm lime green LED equipped plastic cup trap designed by Chu et al. (2003) is the better choice than LED-YC trap because it catches few Eretmocerus spp. and Encarsia spp. whitefly parasitoids released for B. tabaci nymph control. The LED-BC traps caught 2.0-2.5 times more adult western flower thrips Franklinella occidentalis (Pergande) compared with the standard BC traps.

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K.D. Elsey and M.W. Farnham

The relative resistance of 18 cultivars of Brassica oleracea L. to attack by the sweetpotato whitefly [Bemisia tabaci (Gennadius)] was studied in screen cage (spring), field (autumn), and laboratory tests. The B. oleracea entries consisted of six types, including 16 green and two red cultivars. Cabbage (Capitata Group) and broccoli (Boytrytis Group) were less infested than other crops in a screen cage test, with kale, collard (Acephala Group), and brussels sprouts (Germmiter Group) experiencing relatively high and kohlrabi (Gongtlodes Group) intermediate infestations. Relative ranking of crops was similar in an autumn field study, with the exception of brussels sprouts, which had an intermediate level of infestation. Differences in numbers of whiteflies among cultivars within crops were negligible or inconsistent, except that red cultivars of brussels sprouts (`Rubine') and cabbage (`Red Acre') were much less infested than green cultivars. In a laboratory test, differences of whitefly oviposition and nymphal survival and development were small, indicating that nonpreference factors, rather than antibiosis, are the best explanations for differences in the numbers of whiteflies among the B. oleracea cultivars that were tested,

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James D. McCreight

Lettuce infectious yellows virus (LIYV), transmitted by the sweetpotato whitefly, (Bemisia tabaci Genn.), seriously affected melon (Cucumis melo L.) production in the lower desert areas of the southwest United States from 1981 through 1990. Melon plant introduction (PI) 313970 was previously found resistant to LIYV in naturally infected field tests and controlled-inoculation greenhouse tests. Data from F1 and segregating generations from crosses of PI 313970 with LIYV-susceptible lines indicated that resistance in this accession is conditioned by a dominant allele at a single locus designated Lettuce infectious yellows (Liy).

Open access

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

.C. Heinz, K.M. Arthurs, S. 2017 Protecting unrooted cuttings from sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), during propagation J. Insect Sci. 17 4 486 491 Liu, T.-X. Oetting, R.D. Buntin, G.D. 1993 Distribution of Trialeurodes

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Kristen Young and Eileen A. Kabelka

McAuslane, H.J. 2007 Sweetpotato whitefly B biotype of silverleaf whitefly, Bemisia tabaci (Gennadius) or Bemisia argentifolii Bellows and Perring (Insecta: Hemiptera: Aleyrodidae) 25 Mar. 2009 < http://edis.ifas.ufl.edu/pdffiles/IN/IN28600

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Javier Farias-Larios, Mario Orozco-Santos, and Salvador Guzman-Gonzalez

Muskmelon (Cucumis melo L.) is the major cucurbit crop in the Colima state, Mexico. The use transparent plastic mulch continues to increase in that region for high production technology systems of muskmelon, and more recently floating rowcovers were introduced to protect cucurbits from insects (direct pests or vector of viruses) and to increase yield of cucurbit crops. During 1993, yield was evaluated of three cultivars of muskmelon (`Crushier', `Laguna', and `Durango') growing on transparent polyethylene mulch alone or with floating rowcover. The cultivar Crushier showed the higher yield 40 ton/ha (77% for export market), followed by `Durango' with 28.5 ton (77% for export quality) and `Laguna' with about 23 ton (only 40% of export fruit). There was no significant difference in yield between cultivar growth on transparent mulch plots alone and combined with floating rowcover. Also, floating rowcover excluded (until perfect flowering) beetles leafminers, sweetpotato whitefly, and aphids, reducing the use of insecticide by 50%.

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Mario Orozco-Santos, Octavio Perez-Zamora, and Oscar Lopez-Arriaga

The effect of floating rowcover and transparent polyethylene mulch was evaluated on insect populations, virus disease control, yield, and growth of muskmelon (Cucumis melo L.) cv. Durango in a tropical region of Colima state, Mexico. Aphids (Aphis gossypii Glover and other species), sweetpotato whitefly (Bemisia tabaci Gennadius), beetles (Diabrotica spp.), and leafminer (Lyriormyza sativae Blanchard) were completely excluded by the floating rowcover while the plots were covered (until perfect flowering). Transparent mulch reduced aphids and whitefly populations, but did not show effect on leafminer infestation. The appearance of virus diseases of plants was delayed for 2 weeks by floating rowcover with respect to control (bare soil). Also, the transparent mulch reduced the virus incidence. The yield and number of fruit were positively influenced by floating rowcover and transparent mulch. Plot with transparent mulch combined with floating rowcover yielded nearly 4-fold higher (50.9 t·ha–1) than that plots with bare soil (13.1 t·ha–1). The yield from plots with floating row cover on bare soil was of 38.3 t·ha–1, while in the transparent mulch plots it was of 23.1 t·ha–1. The results of this work shows the beneficial effects of floating rowcover and transparent mulch in dry tropical conditions.

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J.L. Bi and N.C. Toscano

Cock, A. Ishaaya, I. Degheele, D. Veierov, D. 1990 Vapor toxicity and concentration-dependent persistence of buprofezin applied to cotton foliage for controlling the sweetpotato whitefly (Homoptera: Aleyrodidae) J

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James D. McCreight and William M. Wintermantel

, 1965 ; Tzanetakis et al., 2003 ; Wintermantel, 2004 ). Sweet potato whitefly, Bemisia tabaci (Gennadius), biotype B (SPWF-B) adversely affects yield and quality of a wide range of vegetable and agronomic crops worldwide directly through feeding