Against Bemisia tabaci you can try with sucrose esters. They are commercially available or you can also used tabaco leaves extracts. These sucrose esters  present naturally in leaves of Solanacea family.  The most active are sucrose acetate, laurinate ot octanoate.

You can use entomopathogenic fungi, e.g. Isaria fumosorosea, Beauveria bassiana, Lecanicillium lecanii , etc.. I have attached a PDF by de Faria and Wraight 2007 which lists the commercial products that are available in different parts of the world. Hope this helps...

You can try with Beauveria bassiana. Several authors have been demostrated the efectivity of this fungus to infest Bemisia tabaci. You can download free the paper from Jun Xia et al 2013 at the following address http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0068185.

 You also can find and download the paper titled: Selection of Beauveria bassiana isolates for control of the whiteflies Bemisia tabaci and Trialeurodes vaporariorum on the basis of their virulence, thermal requeriment and toxicogenic activity. Biological Control 36(3): 274-287. This paper was wrote by Enrrique Quesada-Moraga et al (2006).

You can find it at this web site: http://www.sciencedirect.com/science/article/pii/S1049964405002707

You can try yellow or blue sticky traps

In addition to those products mentioned above, you may want to consider also using botanical soaps (Safer soap), botanical plant oils (emulsified solutions of vegetable oil, soybean oil), and if the problem is very significant use pyrethrin sprays.  These may need to be applied every 7-10 days, repeatedly until the problem is resolved.

Moreover you can use plant extract rich in Alcaloids or Saponins. it has been demonstrated that these metabolites are toxics to pest insects.

Hi, since you are working in green house I suggest entomopathogenic fungi, plant extracts and hexaflumuron. BUt the two first ways are the best.

In Green house you can also work with parasitoids of the genera Encarsia and Eretmocerus which are important natural enemies of Bemisia tabaci. Also predators like Chrysoperla, Orius, Geocoris, Colleomegilla, Coccinella, are usefull as a complement with bio rational treatments. 

The methanolic plant extracts of Fruits of Melia azedarach L. and seeds of Peganum harmala L. were extremely efficient in controlling of adult population of T .vaporariorum compared with the  commercial insecticides.Therefore, it is possible to extract these substances if they have good environmental stability and are environmentally safe, and to use these extracts as botanical insecticides in plant protection against the whiteflies.

parasitoid Encarsia formosa which is common will control Trialeurodes vaporariorum but not Bemisia tabaci, try Eretmocerus mundus, otherwise the EPFs Lenanilicilium lecanii and Beaveria basiana will give you a better control. Check out Dudutech-Kenya website for more information we produce these these products for commercial use in horticultural farms as well as advices of how to use them in IPM set up.

http://www.dudutech.com/product-search/

You may try hot chilli extract or neem extract at 0.5%.

In South Africa, a strain of Beauveria bassiana is registered for the control of white fly. It works especially well in greenhouse environments. It is called Eco-Bb from Plant Health Products, marketed globally by Andermatt.

may you specify the crops that you will grow. just want to know of the habitat diversity in the green house before i propose anything.

You can use weeds having odour to control the same.

Dear Mainali,

very efficient can also be Metharizium anisopliae - an efficient fungal antagonist. There should be some commercial products on the market.  For example in Austria registered as Met52 against beetles but it works also against Bemisia. The other solution may be a treatment with NEEM products. Just a recommendation - try it. Good luck

There are a few reports than yuo can use entomphatogens as Beauveria, Metarhizium, Verticillium and some people use en field mineral oil.

You can try going for yellow or blue sticky traps

Hi, we showed that neem seed oil at 0.5% is efficient to reduce the population and more effective against 1st to 3rd instar nymphs.

http://www.scielo.br/scielo.php?pid=S0100-204X2009000400004&script=sci_arttext

You may refer this publication for the phyto fungicidal control of rust disease.

Article INHIBITORY EFFECT OF LEAF EXTRACTS ON SPORE GERMINATION OF P...

I recommend Isaria fumosorosea (= formely known as Paecilomyces fumosoroseus)...  

I made several tests with bugs (Miridae) and some species work well to control Bemicia tabacci. there are some species that comercialisan and control products.

MIRICAL

Macrolophus pygmaeus (anteriormente conocido como Macrolophus caliginosus)

And other insects

DELPHIBUG

Delphastus catalinae

EN-STRIP

Encarsia formosa

ENERMIX

Encarsia formosa + Eretmocerus eremicus

ERCAL

Eretmocerus eremicus

MIRICAL

Macrolophus pygmaeus (anteriormente conocido como Macrolophus caliginosus)

MYCOTAL

Verticillium lecanii-m

SAVONA

acidos grasos

SWIRSKI-MITE

Amblyseius swirskii

SWIRSKI-MITE LD

Amblyseius swirskii (larga duración)

SWIRSKI-MITE PLUS

Amblyseius swirskii

In South Africa, a strain of Beauveria bassiana is registered for whitefly control as a commercial product. It is in a specially formulated powder to emulsify in water for typical hydraulic spray rigs.

The efficacy of fungal entomopathogens are often relative to the environmental conditions, especially night time humidity and temperature.

The management aproach will depend on the crop species and the type of damage (direct or indirect as the spreading of viruses for example). I did evaluate a bunch of strains of Beauveria bassiana and Metharizium anisopliae in Catie Costa Rica, comercial ones included. I find out that a strain of Metharhizium isolated from insects in Nicaragua worked best, better than mycotal and other comercial products.  Unfortunately this strain is not available.  My suggestion is that you try local pathogens and other biological agents. If the problem is viral spreading the solution will come from tolerant/resistant crops ratjer than controling bemisia. Good luck.

Yellow sticky traps may be used. Since they get attracted to light during night, u may think of using light traps, or install few tube lights, smear with sticky substance like grease, castor oil etc., and the adults get stuck at night

If Bemisia tabaci is new for your place you can start the evaluation of natural enemies, they will start to invade attracted by the pests high level. Collect them, your first impression about the best one can change. About 3 years after the invation you may know which one is helping more. In our case the parasitoid Eretmocerus mundus was excellent regulating Bemisi tabaci biotype B. Meanwhile you can use oil to spread but try to adjust dosage; for us (is a hot place: Bella Vista Corrientes, Argentina) we used 500 cc/hl during the high invasion. After some time Eretmocerus mundus did all the job. Good luck!

Installation of yellow sticky traps. Application of azadirectin based neem product (i.e. NSKE 5% and neem leaves extract.). predators like Chrysoperla, Orius, Geocoris, Colleomegilla, Coccinella, are usefull as a complement with bio rational treatments.  Inundative release of . predators like Chrysoperla, Orius, Geocoris, Colleomegilla, Coccinella, are useful . Apply Beauveria bassiana and Metharizium anisopliae , Lecanicilium lecani and

When it comes to safe biorational greenhouse whitefly control, I would recommend the use of vegetable oil spray. These treatment is not only safe but effective and has a low cost of the active ingredient. Since vegetable oil can have some phytotoxicity you will need to do a rate study for your particular plants of interest. Generally the rate of 0.5 to 2.0% can be quite effective but at higher dose phytotoxicity will kick in. Using a range of concentration for your plants will determine the best under your conditions. The oil is emulsified by adding a liquid detergent used for dish washing until the emulsifying is clear. Using stickty yellow plastic posts can be monitored to review the buildup so applications are made only when a threshold population is being reached. Since the phytoxicity of the oil spray is related to temperature and light applying prior to sun set is an ideal window to avoid phytotoxicity issues. A big advantage of the surfactant oil treatment is than genetic resistance of the target insect has been commonly experienced as in the chemical route of control.

Prof. Paul, you have given good suggestions, but problem is that these vegetable oils does not show consistent results.

The bulk of the responses thus far focus on biocontrol, especially by fungi and parasitoids, with a few mentions of trapping, NEEM extracts, and oils. However, this overlooks some of the best chemistries, which also can be used very safely and in compatibility with biological controls. The insect growth regulators, pyriproxyfen (a juvenoid) and buprofezin (a chitin inhibitor) are quite effective in controlling the immature stages of Bemisia. Spiromesifen is also very good. Spirotetramat has full xylem and phloem mobility, which makes it particularly useful in large structured plants that cannot be adequately covered by spray applications. These compounds have demonstrated full compatibility with a large suite of generalist predators in our system. None should be solely depended on in an IPM system, especially in a greenhouse environment where overuses of these compounds can lead to resistances quickly. Double-door entries and antiviral netting and sealing of the greenhouse is an absolute must.

You may wish to also examine a discussion of the term "biorational", which is variably interpreted around the world and through history. You can find a review here:

You may wish to also examine a discussion of the term "biorational", which is variably interpreted around the world and through history. You can find a review here: www.researchgate.net/publication/233657217_Biorational_Pest_Control_-_An_Overview

You may also review how we have used some of these chemistries to produce a very well-balance, eco-rational IPM program for cotton in Arizona here:

www.researchgate.net/publication/38016124_Fifty_years_of_the_integrated_control_concept_Moving_the_model_and_implementation_forward_in_Arizona