UF/IFAS Sarasota County Extension
Horticulture

Cycad Aulacaspis Scale
(aka Asian Cycad Scale)

Updated March, 2010

Have you noticed a visitor to your landscape? One that makes your Sagos look white? This is the Cycad Aulacaspis Scale (Aulacaspis yasumatsui), also sometimes called the Asian Cycad Scale, an invasive exotic pest which completely covers Sagos and other exotic members of the Cycad family, and eventually kills them. So far, there are few reported cases on Coontie (Zamia floridana) and Cardboard Plant (Zamia furfuracea), so these are still doing fine.

These small white scale insects come in two different shapes and sizes: the males are narrow, rod-shaped and smaller, the females are round, volcano-shaped and much larger. Both are the same species of scale. This pest infests the fronds, the entire trunk, and the lower trunk and roots to six inches deep in the soil, resulting in a Sago which is covered in white from top to bottom. These pests were apparently accidentally introduced from Thailand to the Miami-Dade area in 1996.

So far, research shows that management of this pest requires very rigid adherence to one particular method.  

• Treat with oil. Make an application of horticultural oil (such as in UltraFine Oil) or fish oil (such as Organocide) to the entire plant - top and bottom of fronds and entire trunk.
• Remove dead scale insects. A couple of days later, or the day before re-treatment, remove dead scales clinging to the plant. This can be done with a strong water blast (from a hose-end spray nozzle) or by physically removing the scales from the fronds and trunk with a brush. If the layer of dead scales remain on the plant, then newly hatched scales will simply re-colonize the plant and will be protected from the treatment by the dead scales.
• Re-treat with oil. Seven to ten days following the first application, make another application of horticultural oil or fish oil.
• Repeat Steps 1-3 as necessary until the pest is controlled. Sometimes, it may be necessary to use a systemic insecticide to help, but this will not work by itself. Check to see of the scales are dead by scraping the scales: if they smear, they are still alive; if they flake off they are dead.
• Monitor the Sago on a weekly basis to detect future infestations, then practice steps 1-3 to prevent total take-over by the pest. Avoid using high rates of nitrogen fertilizer of the Sago and surrounding landscape or lawn. Nitrogen encourages growth flushes which are very tasty to the pest and speeds their infestation. If fertilization is required, use a light application of slow-release, low nitrogen fertilizer. Fertilize infrequently.
• Removing the infested fronds will not manage this pest, it will only hasten the decline and death of the Sago.

To learn about how to manage this pest, call the Sarasota County Extension Hort Help Desk at 861-9807 and talk to our Master Gardeners.

Links with information on this pest:

• Cycad Aulacaspis Scale (EDIS document)
• UF ProHort Website