Citrus growers guard against pest

WESLACO — An effort to detect evidence of a deadly citrus disease in California underscores the need for vigilance against the Asian citrus psyllid, the insect that spreads it, Lower Rio Grande Valley experts said Friday.

While only a few psyllids have been found in California, the tiny pests are here, industry experts said.

“We have the vector (insect), but we don’t have the disease,” Bret Erickson, program coordinator for Mission-based Texas Citrus Mutual, said.

While citrus greening, also called by its Chinese name Huanglongbing, hasn’t touched California’s $1.8 billion citrus industry yet, the tree-killing disease has surrounded the Valley, Erickson said.

Citrus greening has already decimated 200,000 acres of citrus trees in Florida, Erickson said, and that makes the fight to control the adult Asian citrus psyllid extremely urgent.

While killing as many adult Asian citrus psyllids as possible is the priority in the Rio Grande Valley, California is in a different position.

California’s approach is novel because it is preemptive: it aims to eliminate the bacteria carrier before it can spread the disease. That’s because, unlike Florida and elsewhere, relatively few invasive psyllids have made it to California thus far.

The first psyllids arrived in Florida in 1998, but officials there didn’t recognize its threat. When the disease was detected six years later, the psyllid population exploded and the disease spread like wildfire, which California hopes to avoid.

In Weslaco, Memoudou Setamou, a citrus entomologist at the Texas A&M University-Kingsville Citrus Center, said he is leading the fight here against the psyllid.

Information and chemicals are available to control the insect, but each grower’s situation is different, Setamou said.

“We have an arsenal of chemicals, but we have to know the circumstances each grower is facing,” he said.

The two most common chemicals for low-volume spraying in citrus groves are known by the trade names Danitol and Mustang, he said.

Homeowners who have a few citrus trees in their yard, garden or patio can buy chemicals specifically designed for small applications at specialized garden centers or at building supply centers, Setamou said.

Texas Agri-Life communications writer Rod Santa Ana III said the Valley is basically surrounded by the citrus psyillid and the situation has gone from serious to a crisis.

“It has severe implications for Valley citrus,” he said.

Citrus seedlings should only be purchased from approved Valley nurseries, not from any source outside the area, Setamou said.

“We are trying to control it,” Setamou said. Growers should be spraying insecticide now because of the recent rains, which are causing citrus trees to flush, which will make them susceptible to the psyllid, he said.

As Erickson and others warned, the Valley already has the insect, which can spread the disease to trees.

“From late October to early February, citrus is dormant, but now they should be spraying,” he said.

“We had a long period of drought from January to June that set the clock black to zero,” he said. “But now they will start flushing again,” he said of trees’ reaction to recent rainfall.

“There are only adults on the trees, they have been waiting for trees to flush,” Setamou said. “Unfortunately, not everybody sprays (pesticide). But if we can cover 90 percent up to 100 percent of the crop, we can control it. We need to create awareness on how to control this pest.”

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The Associated Press contributed to this report.

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Allen Essex writes for the Valley Morning Star in Harlingen.