|
Giant whiteflies can cover a beautiful plant with white
fuzzy wax and sticky honeydew, turning it into an unsightly
mess.
First discovered in San Diego County in October 1992, this
whitefly has spread northward into other areas of California.
Although affected plants may be weakened, they rarely die.
To manage giant whitefly, wash plants off with water and encourage
natural enemies.
What plants are affected?
|
- Many ornamentals including hibiscus, giant bird of paradise, begonia,
Xylosma.
- Fruit trees including citrus, avocado, mulberry and banana.
Look or these damage symptoms on affected plants:
|
- Long, white, waxy filaments produced by the whitefly
give the leaf surface a bearded appearance. These hairlike strands may
be mistaken for a fungal infection.
- Large amounts of sticky honeydew
excreted by the whitefly as it feeds on plant sap.
- Black sooty mold growing on the honeydew.
How to recognize the whitefly:
|
- Adults are small (3/16") and white with light brown
markings on wings and usually found in groups on undersides
of leaves.
- Nymphs are yellowish, small, oval, have no legs and don’t
move.
To reduce problems, use an integrated program that includes:
|
- Removing infested leaves.
- Washing giant whiteflies off leaves with a strong stream
of water.
- Planting species less susceptible to giant whitefly.
- Avoiding insecticides that injure natural enemies, such as
lacewings, lady beetles, syrphid flies, and parasitic wasps.
|
- Don’t use insecticides if beneficial insects, including parasites
and predators, are present in the area.
- To confirm the presence of parasitic wasps, use a magnifying
glass to look for parasite exit holes on giant whitefly nymphs
or darkened nymphs as indicated in drawings below.
- If you do choose to use an insecticide, select least toxic products
such as insecticidal soaps or oils. Remember to follow label directions
and spray the undersides of the leaves where whitefly colonies
are found.


Examine whitefly colonies for grayish-black or yellow nymphs with exit
holes (a), darkened nymphs (b), or healthy nymphs (c).
Minimize the use of pesticides that pollute our waterways. Use nonchemical alternatives or less toxic pesticide products whenever possible. Read product labels carefully and follow instructions on proper use, storage, and disposal.
|