The most effective treatment for whitefly is the parasite "Encarsia". It is supplied on small cards which can be hung up around your plants.  

Glasshouse whitefly are small white flying insects which lay eggs on the undersides of leaves. Whiteflies suck sap from their host plant and drop sticky secretions onto leaves below. Left uncontrolled they will overwhelm the plant, weakening it and flying around in huge numbers. Undersides of leaves become populated with Whiteflies adults and white eggs (scales).

Whitefly are fairly inactive in cool temperatures over Winter, but multiply very quickly in warm Spring and Summer weather. They fly about at the slightest disturbance, like tiny moths, and may even create ghostly white clouds in the air.

Instructions for use

Encarsia are very small (1mm long) flying insects, they lay their eggs inside the eggs of 
the whitefly, and use them as a “nursery” to provide food for their own young.  
They should hatch out from the cards within a week, and the adults will fly around 
seeking out whitefly eggs or pupae. The time taken from egg to adult is from 10-31 
days, depending on temperature.  You will get best results when temperatures are  20° 
to 25°C. 

Hang cards on lower branches so that they may be in a slightly shady position.

5 cards should give good control for an average conservatory or small greenhouse. If you have a longstanding battle with whitefly follow up the initial treatment with a second introduction one weeks later.  If you have a low lever of whitefly or are using Encarsia as a preventative method then application can be every 2 weeks.

Identifying Whitefly

Remember whiteflies are nearly always moving. If you see white threads static on tops of the leaves, they are not whitefly but something else - very likely to be shed aphid skins dropped down from developing Aphid under leaves above. Or they could be thrips larvae. They are not "whitefly" unless body and wings are a ghostly white.

The glasshouse whitefly (Trialeurodes vaporariorum)is the most common. You can recognise them by their heart-shape profile when looked from above. Tobacco whitefly (Bemisia tabaci) have parallel wings which are longer, and when folded you can still see a strip of their back between the wings. There are up to 50 different species of whitefly in Europe, but from a gardeners point of view they are all plant pests. 

Although Encarsia is very effective for the common glasshouse whitefly, it doesn't work so well for tobacco whitefly. It's therefore worth trying to identify what whitefly you have before treating. If you need any help identifying the whitefly you have then please don't hesitate to contact us.

NB This predator is only active at temperatures in excess of 18-20°C

Biological controls are not always kept in stock, they are ordered in fresh.  This can sometimes lead to a time lag between when you place the order and when it is despatched.  Order by 10am Monday for same week despatch by Lady Bird Plant Care.

The smallest packs (5 & 10 cards) are only available March to mid September. 

Contents

In your package you will find strips of cards. You can see the black dots stuck on each 
card – these are your eggs, or “scales”.  Separate the cards from each other, and hang 
each one on a branch in a shady place about half way down affected plants. (For 
smaller plants that won’t support a card just fix the card somewhere near the crop). 

NB The appearance of the cards will not change over their lifespan. 

Further information 
a)    Use fresh, don’t store. 
b)    Keep cool before putting the cards out 
c)    Avoid pesticides as they will kill these insects too. 
d)    Separate cards but don’t touch the little black dots – they are alive! 
e)    If you have no Whitefly and you are using this as a preventative method, make sure 
you replace the cards every 2 weeks. 
f)  Make sure you treat early, as soon as temperatures in your growing area reach a 
minimum of 15-20°C.