Foreign Bugs Taking Toll on Sago Palms

The leafy Sago Palms that are a fixture in Rio Grande Valley, Texas landscaping are under attack.

Tiny, white insects mistakenly brought to the country from Thailand and first found in Florida are ravaging the plants from Hidalgo to Cameron counties, with the heaviest damage in the east, said Boris Castro, a Texas Cooperative Extension entomologist at the Texas A&M Agriculture Research and Extension Center at Weslaco.

The situation could deteriorate, as the bugs have no natural enemies in the area and rapidly proliferate.

Don’t panic, though.

"This is not the end of sago palms," Castro said. "This is just one insect we have to deal with right now."

But in the past, other plants have been wiped out because of an invasive element, said Hidalgo County Agriculture Extension Agent Brad Cowan.

"There used to be thousands of date palms in the Valley and now there’s hardly any left," he said. "A virus in the 1970s came in and wiped them all out. "It was a real devastating thing at the time."

The Asian cycad scales, also known as the sago palm scale, are the current threat facing the sago palms. The insects can burrow in the plant’s roots and feed on plant juices, causing the plant to wilt, turn yellow and die.

If the plant does not die, it becomes susceptible to other plant diseases like root rot or other fungal infections, Castro said.

Dorian Madrigalcq, owner of Shary Acres in Mission, said the nursery has treated several sago palms in the past few weeks at residential homes covered with a fungus.

"We are using a fungicide to treat a problem," he said. "It’s nothing that can’t be taken care of."

The Asian cycad scales first arrived in Florida in the early 1990s and cost millions in losses to the landscape industry and property values, according to an article Texas A&M communication specialist Rod Santa Ana III recently wrote for The Monitor.

The insect came to Texas in 2001, was detected in 2002 and reached outbreak levels this year, Castro said.

"There are a lot of things we’re learning about this insect" through an ongoing U.S. Department of Agriculture study, he said.

"It is in very heavy numbers when you move east, like Harlingen, Brownsville, South Padre Island, but as you start moving to Weslaco, McAllen, there are very low numbers."

A ray of hope lies in microscopic wasps that could destroy the Asian cycad scales. These bugs have been released on sago palms in Florida, but have yet to reach the Valley.

Homeowner and landscaper vigilance, combined with better insect control chemical products, makes a situation that the date palm encountered not as likely, Cowan said.

"We really didn’t have any treatment options in the 1970s," he said.

"Hopefully, this is not something like that, (but) only time will tell."

The Extension service is working with several agencies, including the Texas Department of Agriculture and the University of Florida, to develop long-term solutions such as biological pest control, Castro said.

For now, homeowners should carefully inspect a plant before purchase. If they do find infestation, they can apply high-pressure water to clean it, but must do it twice a week.

Or they can go to a garden center and buy plant spray oils specially formulated for plants and combine them with high-water pressure.

And as a last resort, they can use carbaryl or acephate insecticides.

"With all these measures, the prospects look good," Castro said.