Glasshouse Whitefly, Greenhouse Whitefly
Glasshouse Whitefly is a small, moth-like, sap-sucking bug (Hemiptera). Whitefly is an important agricultural pest that has been a problem for many commercial growers over the last decade. Whiteflies suck up plant tissue through two finely adapted stylets. Their feeding can be invasive and has the potential to transmit diseases between plants. Additionally, whiteflies secrete copious amounts of honeydew, a byproduct of whitefly feeding, over plant foliage. Honeydew can attract mould, which can also weaken plants by reducing the rate of photosynthesis.
Whitefly is an agricultural pest which can transmit disease from their feeding.
They can feed on a wide variety of indoor-grown plants making severe infestations more likely.
Adults: Tiny, growing only 1.5 mm, with four white wings. They are pearly white and often fly up 'in clouds' when disturbed. Nymphs: Oval and flattened, translucent with a green tinge. A powdery white wax usually is evident when a nymph has settled to feed. Later nymphal stages appear more like scale insects, immobile and latch to the plant. The final nymphal stage takes the form of a flattened disk, with a fine waxy fringe spanning the body. Eggs: The whitefly eggs are pear-shaped, yellowish, and very small. They are also inserted within the leaves tissue, so cannot be seen with the naked eye.
Small, white insects under leaves of plants. Whitefly eggs are typically laid in a circular arrangement, beneath the leaves. White insects might fly from foliage when disturbed, Clear, sticky drops of honeydew on foliage. Black sooty mould on foliage. Powdery white waxy deposits on infested leaves. Stunted growth, or malformed and curling leaves.
Whitefly infestations tend to be more problematic indoors, for example, in a glasshouse setting. In most cases, whitefly is spread to glasshouses via new plants. Check or quarantine plants for any nymphs prior to putting it in the greenhouse. Planting rhubarb in greenhouses is thought to deter whitefly too. Whitefly eggs can be found underneath the leaves of plants, so these areas should be inspected regularly. Remove Whitefly eggs with a cloth and soapy water or rubbing alcohol. Any spacing between plants should be kept clear of weeds and debris. The use of netting can sometimes improve protection. For lighter infestations, plants can be gently hosed down to remove whitefly and eggs. Ant traps placed near affected plants will aid controlling any secondary infestations. Whitefly is drawn to the colour yellow. You can use yellow cards or sticky traps to attract whitefly and monitor the infestation level. Insecticidal soaps and neem oil can give some control over whitefly, and it's less harmful to the environment when compared with pesticides. Bottle labels should be read carefully. Oils can react badly with high temperatures and burn the surfaces of plants. Beneficial garden creatures such as beetles, wasps, lacewings and spiders will eat whiteflies. These can be attracted into the garden using a few simple tricks, such as incorporating insect hotels or by letting parts of the garden grow a little wild.
There are pesticides available for home gardeners. Please note; whiteflies easily develop resistance to pesticides. Systemic insecticides can sometimes eliminate whitefly, be sure to get good coverage beneath the leaves (where the younger whitefly hide). Please read bottle instructions carefully, taking care not to spray any plants that are in flower. Such pesticides can be extremely toxic to wildlife, so should be applied with caution. If you are planning to eat your harvest, make sure the food plant is listed on the bottle label and take care to follow instructions.