Cabbage whitefly (2016)

Michael R. Bush, Christopher Adams, and Sven Spichiger

While cabbage whitefly is primarily a new pest of brassica crops. It also attacks other brassicas that are bedding plants and ornamentals.

Pest description and damage Cabbage whitefly adults and nymphs are likely to infest outer or exposed leaves of brassicas. Damage is often limited to leaf curling, yellowing and the presence of sooty mold growing on the honeydew. Cabbage whitefly damage is limited to outer leaves and to ornamental brassicas, especially ornamental leafy kale. When the problem is persistent, check nearby brassicaceae weeds for whiteflies. As these weeds mature or die off, whiteflies will fly to more valuable plants. Adults are small, white, moth-like, have white wings and a waxy, white thorax. When abundant, they fly up in great clouds from host plants. The nymphs are whitish-green, flattened and oval with dense waxy exudate covering them. Different species of whitefly look very similar, but can be differentiated by comparing digital images or physical specimens. Cabbage whitefly might be mistaken for the greenhouse whitefly, but GHW have long wings, a yellow thorax and a much wider host range. Adults and nymphs are vectors of a great number of viruses.

Biology and life cycle Adults overwinter on the host plants, including nearby related weeds. Nevertheless, cabbage whitefly can spend the entire year on one host plant.

Pest monitoring The presence of paper wasps and yellowjackets cruising through ornamental beds should cause the gardener to check plants more closely. These wasps are great predators and when abundant may be feeding on whitefly prey and whitefly honeydew. Monitor for whitefly with yellow sticky traps placed next to suspect plants.

Management—cultural control

Isolate all incoming plants in a separate area until you can inspect them for the presence of eggs, nymphs or pupae. Unfortunately, the more visible adults may not be present at the time your shipment arrives.

Management—biological control

There are several effective biological control organisms such as the parasitic wasp, Encarsia formosa and predatory Delphastis beetles. A good biocontrol consultant can match host whitefly to an effective predator or parasitoid and then guide you on proper timing releases.

For biology, life history, monitoring and management

See “Whitefly” in:

Management—chemical

See “Whitefly” in Table 1:

For further information:

Oregon Department of Agriculture. 2016. Pest Alert: Cabbage Whitefly, Aleyrodes proletella. https://www.oregon.gov/ODA/shared/Documents/Publications/IPPM/CabbageWhi...