Trialeurodes vaporariorum (Westwood)
Taxonomic placing: Insecta, Hemimetabola, Hemiptera, Sternorrhyncha, Aleyrodidae.
Common name: Glasshouse or greenhouse whitefly.
Host plants: Polyphagous.
Geographical distribution: Almost cosmopolitan.
Morphology: The first-stage crawlers are yellow-green. After molting they are apodous, scale-like, remaining yellow. During the fourth, final stage (often called “pupa”), eyes and other body parts can be seen, a few long stiff setae protrude from the body and a fringe of white waxy setae is produced. Adults are 1–2 mm in length, with yellowish bodies.
Two distinct populations of T. vaporariorum, differing in biochemical and allozime markers, have recently been reported; their taxonomic status remains unclear.
Life cycle: The parthenogenetic females lay their several hundred eggs on the undersides of young leaves. The emergent crawlers are the only mobile immature life-stage, whereas the adults can fly. Optimal conditions for development are at 21-24°C, and a cycle can be completed in about three weeks and under benign conditions. In the Middle East the pest develops the year around, completing several annual generations. This pest is relatively susceptible to higher (>30ºC) temperatures.
Economic importance: The greenhouse whitefly is a world-wide important pest of many vegetable and ornamental crops in glasshouses, being especially injurious to tomatoes. The damage is four-fold. Feeding on the foliage reduces plant vigor and growth, resulting in greatly diminished crop yields. Then, the pest excretes copious amounts of honeydew which is colonized by disfiguring sootymold, further increasing the damage. Third, this pest transmits several plant viruses that affect various vegetables, including cucurbits, potatoes, and tomatoes. And fourth, T. vaporariorum may disperse another serious tomato pest, Polyphagotarsonemus latus.
Horticultural methods: Removal of other crop and non-crop plants, including weeds. Thye are alao infested by the pest and thus may serve as infection reservoirs.
Monitoring: Yellow sticky traps are used to monitor whitefly invasions into greenhouses and to monitor their numerical increases therein. In the greenhouse leaf samples should be taken and the infesting crawlers counted under a microscope.
Physical control: UV absorbent plastic films, used as greenhouse covers, reduced pest infestations therein.
Plant resistant: Cultivars of several crops (like tomato and soybeans) that are tolerant or resistant to the pest have been found.
Suppression of populations: Numerous sticky traps placed in greenhouses may reduce whitefly numbers.
Chemical control: The greenhouse whitefly has become resistant to many insecticides. Essential plant oils, insecticidal soaps and diatomeaous earth are in use.
Biological control: Effective whitefly control has been obtained with various natural enemies. These include parasitoids like Encarsia formosa (Gahan), Eretmocerus eremicus Rose and Zolnerowich (both Aphelinidae) or Amitus fuscipennis MacGown and Nebeker (Platygasteridae). Efficient predators include Macrolophus pygmaeus Rambur (Miridae), the coccinellid Delphastus pusillus ((LeConte) and the phytoseiid Amblyseius swirskii Athias-Henriot. Commercial formulations of entomopathogenic fungi, such as Beauveria bassiana (Balsamo) Vuillemin, Paecilomyces fumosoroseus (Wize) Brown and Smith and Lecanicillium muscarium Zare and Gams have also been applied.
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Choi, W.-I., Lee, E.-H., Choi, B.R., Park, H.-M. and Ahn, Y.-J. 2003. Toxicity of plant essential oils to Trialeurodes vaporariorum (Homoptera: Aleyrodidae). Journal of Economic Entomology 96: 1479-1484.
Erdogan, C., Velioglu, A.S., Gurkan, M.O., Denholm, I. and Moores, G.D. 2012. Chlorpyrifos ethyl-oxon sensitive and insensitive acetylcholinesterase variants of greenhouse whitefly Trialeurodes vaporariorum (Westw.) (Hemiptera: Aleyrodidae) from Turkey. Pesticide Biochemistry and Physiology 104: 273-276.
Feng, M.G., Chen, B. and Ying, S.H. 2004. Trials of Beauveria bassiana, Paecilomyces fumosoroseus and imidacloprid for management of Trialeurodes vaporariorum (Homoptera: Aleyrodidae) on greenhouse grown lettuce. Biocontrol Science and Technology 14: 531-544.
Lambert, A.L., McPherson, R.M. and Espelie, K.E. 1995. Soybean host plant resistance mechanisms that alter abundance of whiteflies (Homoptera: Aleyrodidae). Environmental Entomology 24: 1381-1386.
Mutwiwa, U.N., Borgemeister, C., Elsner, B.-von and Tantau, H.J. 2005. Effects of UV-absorbing plastic films on greenhouse whitefly (Homoptera: Aleyrodidae). Journal of Economic Entomology 98: 1221-1228.
Parker, R. and Gerson, U. 1994. Dispersal of the broad mite, Polyphagotarsonemus latus (Banks) (Heterostigmata: Tarsonemidae) by the greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Homoptera: Aleyrodidae). Experimental and Applied Acarology 18: 581-585.
Perdikis, D.C. and Lykouressis, D.P. 2003. Life table and biological characteristics of Macrolophus pygmaeus when feeding on Myzus persicae and Trialeurodes vaporariorum. Entomologia Experimentalis et Applicata 102: 261-272.
Romanow, L.R., de Ponti, O.M.B. and Mollema, C. 1991. Resistance in tomato to the greenhouse whitefly: analysis of population dynamics. Entomologia Experimentalis et Applicata 60: 247-259.
Seiedy, M. 2015. Compatibility of Amblyseius swirskii (Acari: Phytoseiidae) and Beauveria bassiana for biological control of Trialeurodes vaporariorum (Hemiptera: Aleyrodidae). Systematic and Applied Acarology 20: 731-738.
Shin, D., Mo, H.H., Lee, S.E., Park J.J. and Cho, K. 2013.- Elucidation of the genetic differences in Trialeurodes vaporariorum populations under vegetable greenhouse conditions by using the allozyme approach. Entomological Research 43: 271-281.
van Lenteren, J.C., van Roermund, H.J.W. and Sütterlin, S. 1996. Biological control of greenhouse whitefly (Trialeurodes vaporariorum) with the parasitoid Encarsia formosa: How does it work? Biological Control 6: 1-10.
Yano, E. 1989. Factors affecting population growth of the greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Homoptera: Aleyrodidae). Japan Journal of Applied Entomology and Zoology 33: 122-127.
Web sites http://www.extento.hawaii.edu/kbase/crop/type/t_vapora.htm