Cycads also known as coonties and sago palms are valuable landscape plants in Florida being natives and both salt and drought tolerant. These ancient plants, which shared the planet with dinosaurs thousands of years ago, are under attack.
More than 20 species of scale insects occur on cycads in Florida, the most damaging of which is the cycad aulacaspis scale. (Aulacaspis yasumatsui Takagi). Cycad aulacaspis scale is native to the Far East but has spread around the world and is currently blanketing Florida at record speed. Over the last two years, sharp eyed gardeners have noticed cycad scale creeping across Franklin County. Especially deadly to cycads this sucking insect encrusts the fronds with an unsightly dirty white mass that causes yellowing, spotty pigmentation and eventually death.
The best chemical control comes from oils either paraffin-based ultra-fine horticultural oils, or Organocide, which is 95% fish oil. When applied to foliage and trunks of infested cycads oils greatly reduce the scale insect populations. Control may require several applications.
At least 24 hours after applying oil, use a hard stream of water to rinse away the dead insects and reapply oil.
Repeat as needed.
Greater scale mortality can be achieved by mixing oils with a contact insecticide, like Malathion or Sevin. In some cases roots of the plants are infested and a soil drench with a contact pesticide can help with control.
Pruning is the second phase of treatment. Remove dead or badly damaged foliage. Always practice plant sanitation in pruning infested plants. Clean pruners with alcohol and remove all damaged material pruned from infested plants and either bag and send to the landfill or burn.