November Pest of the Month: Whiteflies

There are number of species of whiteflies in Australia that are important nursery production pests. The most common of which are known as silverleaf whitefly, glasshouse whitefly, ash whitefly and spiralling whitefly. These pests are commonly first observed when a cloud of small, white insects fly from the crop when plants are disturbed. Unfortunately, this is often too late to manage optimally. Immature whiteflies are very small and can be quite difficult to detect unless specific monitoring is completed with a hand lens.

Management of these pests are best completed proactively. Keep a record of when your nursery experiences problems and ensure that monitoring of susceptible plants occurs throughout high risk seasons, typically in spring and Autumn. This is particularly important if you experience whiteflies on a regular basis and are growing plants for which viruses infect your crop, e.g. tomatoes and other solanaceous hosts.

Key management actions include regular monitoring, managing weeds, resistant varieties, using protected cropping structures (and keeping doors closed), using good general hygiene practices to limit spread of infested plants to other areas of the nursery. A number of biological control agents are available that may be suitable in your nursery, these are available through Bugs for Bugs and Biological Services. Low risk pesticides are also available against whiteflies.

More information on whiteflies, their identification and management is available in the whitefly pest management plan. This plan includes many pesticides that are available, however additional minor use permits are available and can be found at the Australian Plant Production Standard website. Search for whiteflies at the top right hand corner of the table. In addition, photos of whiteflies are available at the pest ID tool.

Image caption: Glasshouse whitefly pupae that have emerged as adults (below) and not yet emerged (above).