Is There a Solution to Asian Cycad Scale?

In the longer term, the ideal solution is one or more natural predators / parasites. Researchers at USDA are currently rearing two insects to serve in this role. One is a predatory beetle and one is a parasitic wasp.

The biological approach will not be quick fix as it may take several years for the predator populations to increase to the point they can truly be helpful. Many counties across Florida have begun to release parasitic wasps including Hillsborough County in 2002.

Parasitic Wasp (Coccobius fulvus)

One solution that has proven somewhat effective, especially on smaller sagos is to simply spray the plant with a hard stream of water from a hose (Mannion, 2003). Done regularly and thoroughly this technique can at the least, slow the pest down drastically.

The latest research (Mannion, 2003) indicates that many products sold for the control of scale work effectively on the Asian cycad scale. Horticultural oils (Ultra-Fine, summer oil, volck oil, dormant oil, etc), fish oil (not fish emulsion) and Malathion-in-oil all yield good results.

Contact pesticides, such as Malathion, kill insects by touching them. Systemic insecticides, such as those with the active ingredients acephate, dimethoate, disyston and imidacloprid, move into the sap system of the plant. The insects are then poisoned when they feed on the sap of the plant. Research shows that imidacloprid is not very effective on Asian cycad scale.

Dimethoate, sold under various brand names, such as Cygon®, has been shown effective on this pest, but production of this chemical has been discontinued. Stocks on this product are slowly being used up and this option may not be around much longer.

Several new and effective treatment options have recently been introduced. One is an insect growth regulator called Distance®. The active ingredient in Distance® is pyriproxyfen. Due to the high cost of Distance® it’s primarily a commercial product.

Another recent chemical introduction is Safari™. The active ingredient in Safari™ is dinotefuran. Safari™ is available through stores that specialize in selling pesticides to commercial applicators. It is not available in homeowner sized quantities at this time, therefore is very expensive per package. However, the cost per application becomes more reasonable if the effort required for protection is decreased and the protection itself is increased. The active ingredient in Safari™ is very water soluble making appropriate pesticide protective equipment essential.

We recommend using either horticultural oil or Organocide™ as they appears to be quite effective with minimal disruption of beneficial insects.

Be cautious of spraying any chemical in the heat of the day, especially to any new growth that might be present. Spraying earlier in the morning or later in the evening will help avoid damage.

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