White Mold or Scale on Sago Palms

Identification

• A waxy, white crust resembling a mold develops on the Sago palm tree's fronds when infested by the Cycad Aulacaspis Scale (Aulacaspis yasumatsui), also referred to as the Asian cycad scale. This white crust on the fronds is made up of thousands of dead and living scales, sometimes several thousand per square inch.

Origin

• The Cycad Aulacaspis Scale is native to Thailand. It was first documented in Florida in 1996. It is now distributed throughout the Southeastern U.S. in addition to other tropical and subtropical portions of the country including Texas, California and Hawaii. As a relatively new species to the country, it has no known natural predators, reproduces, and thrives with impunity. Generations overlap and infestation can ramp up quickly.

Warning

• The pest primarily attacks sago palms of the genera Cycas, Dioon, Encephalartos, Microcycas, Stangeria and Macrozamia, indicates the Texas Cooperative Extension Service. The King and Queen sagos are particularly susceptible. Cycad Aulacaspis Scale can kill a tree within weeks or months and almost always within a year. Monitoring Sago palm for signs of infestation is the best control method. Early attacks are easier to manage.

Symptoms

• The first sign that this scale is present is the deposit of tiny, orange eggs on the undersurface of Sago palm fronds. As the adults emerge and begin feeding, a yellowing on the upper surface of the palm fronds develops. The Cycad Aulacaspis Scale sucks the tree's juices, drying the foliage and eventually causing a browning of the leaves with accompanying holes. As the number of scales increase, the characteristic white, waxy mold appears.