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Silverleaf whitefly (SLW) is considered a major pest of cotton due to resistance issues and the difficulty in processing lint contaminated with SLW honeydew.
- SLW biotype B
- 1.5mm long
- white powdery wings held at an angle with a gap at the apex (when viewed from above the body can be seen between the wings).
- pale yellow-green
- flat and scale-like
- attach to the underside of the leaves
- most nymph stages are immobile
- maturing nymphs develop 2 red eye spots.
Distribution and habitat
Recorded in cotton crops in eastern Australia and from Katherine in the Northern Territory.
Cotton, soybean, peanut and many broadleaf weeds.
- High reproduction rate and short generation time results in large numbers that can retard plants simply through feeding.
- Secretes large quantities of honeydew that interfere with photosynthesis and cause problems with cotton fibre processing.
- Potential carrier of viruses not yet in Australia (such as cotton leaf curl).
The life cycle from egg to adult can be as little as 18 days in the summer, but longer in cooler weather.
Monitoring and thresholds
Sampling methods and a threshold matrix are discussed in detail in the cotton industry’s annual Cotton Pest Management Guide.
Identification of parasitised nymphs is best done with a digital microscope.
A significant problem is SLW's ability to develop resistance very quickly when insecticides are used repeatedly. Consult the cotton industry's integrated resistance management strategy (IRMS) and other management information in the Cotton Pest Management Guide before applying pesticides.
Conservation of natural enemies and good crop hygiene are key components in SLW management. Avoid early-season use of broad spectrum insecticides, particularly pyrethroids and organophosphates.
- Managing silverleaf whitefly in Australian cotton—CottonInfo
- Several silverleaf whitefly videos are available on the CottonInfo YouTube channel (search for 'whitefly')
- Registered chemicals database—Australian Pesticides and Veterinary Medicines Authority (APVMA)
- Last reviewed: 14 Jan 2020
- Last updated: 21 Dec 2018