How to Control Scale Infestation in a Sago Palm

Heavy scale infestation can kill a palm in one year.

The cycad scale (Aulacaspis yasumatsui) can severely infest the sago palm (Cycas revoluta). The insect, a native of Thailand, first invaded Florida in 1996. Scales infest the tree's root system, trunk and leaves. The female scale insect covers itself with an oval-shaped, waxy covering, while the male forms an elongated armored covering. The female lays approximately 100 eggs beneath the protective covering. Upon hatching, the scale nymphs crawl out from under the covering and begin to suck the tree's sap. The wind spreads the lightweight nymph insects to other sago palms.

Things You'll Need

• Pruning shears
• Horticultural oil
• Garden sprayer
• Systemic insecticide
• Insect growth regulator

Instructions

1. Prune away all infected leaves and dispose of them.

2. Spray the sago palm with horticultural oil, covering the trunk and palm fronds completely. Apply the oil four times over the course of 10 to 14 days.

3. Apply a systemic insecticide that contains dinotefuran to control the cycad scale. Follow the directions on the insecticide's label for application instructions.

4. Apply an insect growth regulator that contains pyriproxyfen or buprofezin. Follow the directions on the label for application instructions and frequency of use.

Tips & Warnings

• Sago palms infested with scale insects appear to have a white coating. The leaves may turn yellow or brown and eventually die.

• Hemispherical scale (Saissetia coffeae), hibiscus snow scale (Pinnaspis strachani) and cockerell scale (Pseudaulacaspis cockerelli) can occur on the sago palm but usually do no significant damage. Naturally occurring parasitic wasps can help control scale.

• The cycad scale can coat the tree's root system to a depth of 24 inches.

• A medium-sized sago palm can perish within a year from heavy infestation of cycad scale, according to the University of Florida IFAS Extension.

References

• University of Hawaii: Cycad Scale on Sago Palm
• "Hawaii Department of Agriculture"; Sago Palm Scale; Ronald A. Heu, et al.; Sept. 2003
• University of California: Scales
• "Texas A&M University"; The Cycad Aulacaspis Scale, a Pest of Sago Palms in Texas; Carlos E. Bográn, et al.; Sept. 2006
• University of Florida Extension: Asian Cycad Scale
• University of Florida: Cycad Aulacaspis Scale on Sago Palm

Resources

• "The Florida Times Union"; Asian Cycad Scale Damaging Area Sago Palms; Terry Bright Delvalle