Coronavirus (COVID-19) update: We are currently updating information following recent Queensland and Australian Government announcements. Find assistance and support for coronavirus affected businesses and industries.

Silverleaf whitefly

Silverleaf whitefly (SLW) is considered a major pest of cotton due to resistance issues and the difficulty in processing lint contaminated with SLW honeydew.

Scientific name

Bemisia tabaci MEAM1

Other names

  • SLW biotype B

Description

Adults

  • 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).

Nymphs

  • 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.

Hosts

Cotton, soybean, peanut and many broadleaf weeds.

Damage

  • 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).

Life cycle

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.

Control

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.

Further information