An exotic scale insect is attacking Pygmy date palms and true date palms in our area. It is called Red date scale (Phoenicoccus marlatti) and it attacks Phoenix species palms all over the world, but within the United States it is only found in Florida.

Red date scale was first found in Indian River County by Bug Masters horticulturist, Brian Combs in 2003 on a Pygmy Date Palm in Johns Island. Since that time it has spread throughout the area and the number of finds from around the state has increased as well. 

 

The mature scale is about 1.5mm long, spherical, red or reddish brown. It does not produce a hard shell, but instead forms a white wax covering the body in shining white strands. It usually infests the newest fronds emerging from the heart first. These fronds are tightly wound before unfurling, thus making control with contact materials almost impossible.

 

Red date scale is difficult to manage for several reasons: 1) It has repeating generations meaning new scales are constantly being produced, 2) it can take as little as 60 days to go from an egg to a reproducing adult, 3) some eggs hatch within the females resulting in live birth of scale crawlers, 4) they can infest the leaf spear before it emerges and unfurls, 5) exposed and underground roots may also be infested, and 6) being an exotic pest, natural predators are not present in enough numbers to keep it in check.

 

Pygmy date palms planted in shady areas appear to be suffering the most, but we have found it on plants in the full sun as well. 

 

Control measures have not been thoroughly researched, but it is generally thought control strategies used for other scale insects will give acceptable control.

 

Our control measures include contact sprays using oils and insect growth regulators and drenches of systemic materials. We can control this pest but not eliminate it. As with other scales, even after treatment the scale bodies and waxy material will stick to the plant for some time until washed off by hard rain. For those plants under eaves or not exposed directly to hard rains, it may take months of the old scale bodies to disappear.

 

Our technicians are trained to inspect and treat for Red date scale. As with other exotic pests such as Fire ants, Sago palm scale, and Pink hibiscus mealybug, we are going to have to learn to live with these insects. If found and treated they usually do not cause the palm to die, but left untreated plant death has been recorded. 

 

The symptoms on large Dactylifera palms appear quite different than the Pygmy date palms. The leaflets turn a light tan color throughout the canopy. For those not familiar with this symptom, incorrect diagnosis is quite common. Effective treatment may require a bucket truck to reach these large palms.

 

Written by: Brian Combs, General Manager