Encarsia

Adult WhiteflyAdult whitefly are small, white, waxy-winged insects congregate at the top of the plant, but fly off if disturbed. Both the adults and larval stages of the whitefly suck sap from the leaves resulting in stunted growth and damaged leaves. The sap contains excess sugar which is excreted by the whitefly and coats the lower leaves. Mould then develops, which is unsightly and produces poor growth. A Whitefly infestation can be brought into your greenhouse / conservatories by bringing in infected plants, so carefully inspect any new ones or they can come in through open windows / open greenhouse vents in warm weather. They are capable of laying up to 200 eggs in groups on the underside of the leaves, so numbers can build up quickly. Tiny larvae emerge ,which search out suitable feeding sites and lose the ability to move. This immobile "scale" stage is pale green, about 2mm long and lives under the lower leaves only. The life cycle consists of adult laying eggs, to larvae, to scale and finally to adult, this whole process can be completed in as little as 3 weeks in the summer. To control whitefly :-

• Introduce Encarsia as sson as the daytime temperature averages 10°C / 50°F and the whitefly are 1st spotted. 
• Hang yellow Glue Traps alongside plants to monitor / control whitefly alongside Encarsia.
• If the temperature is below 16C/50F, use SB Invigorator Natural Spray to hold the fort until temperatures rise and then introduce Encarsia.
• If the infestation is very heavy then spray with SB Invigorator first to reduce numbers before introducing Encarsia - see our Whitefly Emergency Pest Pack.

N.B. Whitefly should not be confused with aphids, which shed their skin leaving them on the leaves. To tell the difference shake the plant, whitefly will fly off whereas aphid skins will remain stuck. If it is aphids, use aphidius / ladybirds / lacewings for control instead.

Control whitefly in your greenhouse / conservatory by introducing Encarsia Formosa AS SOON as the first whitefly appear and the temperatures are above 10°C / 50°F. Encarsia is a natural parasite of whitefly - it is a tiny insect with clear wings that seeks out whitefly scale and deposits an egg inside it. As the beneficial Encarsia develops INSIDE the whitefly scale, the whitefly is destroyed and turns black, before a new Encarsia emerges ready to repeat the cycle. Each Encarsia is capable of laying 300 eggs inside 300 whitefly scales in 30 days. It is safe for you, children, pets and wildlife. Food crops such as tomotoes can be harvested continually, where Encarsia is used.

Encarsia is introduced into the greenhouse / conservatory as small, black dots on cards, which are simply hung on the lower leaves of the plants - the easiest gardening you will ever do! Each delivery of Encarsia consists of a number of cards (5 or 10), with each card producing approx 60 Encarsia i.e. a delivery of 5 cards produces approx 300 Encarsia. Simply seperate the cards along the perforations and hang them around the greenhouse / conservatory on the lower leaves of the infected plants. Each order for Encarsia consists of 2, 4 or 8 separate deliveries at 7 day intervals, which allows the Encarsia numbers to build up naturally resulting in better control. How much Encarsia is needed :-

• For a small greenhouse where the whitefly have just appeared - use 2 introductions (5 cards per introduction) at 7 day intervals.
• For larger greenhouses or where the whitefly have had time to get established - use 4 introductions (5 cards per introduction) at 7 day intervals.
• For large greenhouses where plants are being moved in and out or where you have had a persistent whitefly problem in the past and you want to introduce Encarsia to keep whitefly at bay during the growing season - use a Economy pack of 8 intorductions (10 cards per introduction) @ 7 day intervals.
• If the infestation is very heavy, spray with SB Invigorator 1st and then introduce Encarsia - see our Emergency Pest Pack (SB Invigorator followed by 4 introductions of Encarsia).

N.B. If you have recently used a chemical spray i.e. within the last 2-3 weeks, please contact us (jess@greengardener.co.uk) to check how soon Encarsia can be introduced?