How Can the Asian Cycad Scale be Controlled?

The long-term solution is to find, raise, and release predator / parasites. This is being done by the USDA, DACS, and IFAS.

The short term solution is to control the pest on as many plants as possible:

  1. The first step is to treat the plants to reduce the populations of the scale.
  2. The second step is to treat the plants preventively until the predator population can grow to the point that the scale is controlled naturally.

In the research that has been done, it was noted that within 21-35 days of hatching, Asian cycad scale females could begin laying eggs in warmer weather (Hamon, 2000). To prevent new generations of scale from hatching and to bring this pest under control, spray every other week in warmer weather (above 70° F) and once a month in colder weather (below 70° F).

Make sure the spray application is very thorough. Best results are obtained using a fine spray, so pump-up sprayers using adequate pressure to get into the nooks and crannies are preferable. Any gaps in coverage allow the population to rebound quickly. Nearby infested plants can also spread the scale back to plants that have been treated.

Spray the cycad down hard with a garden hose to loosen the dead scale occasionally. Preventative treatments can be either every other week or once a month (remember to be thorough) This should keep the sago safe while biological controls gain momentum. Don’t forget to treat the soil under the sago fronds at the same time you’re treating the fronds. The research does not indicate how often to treat the soil, but every other month should suffice.

Systemic chemicals with active ingredients like acephate, dimethoate, disyston and imidacloprid have yielded mixed results. These systemic chemicals may also interfere with the establishment of the predatory insects (Howard, 2003) so they should be used only in severe infestations and then only on a limited basis, switching to oil or Malathion-and-oil soon after.

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