Eucalyptus Trees and Environs Falling Victim to Insidious Pest

Two months ago, the courtyard at St. Sebastian Catholic Church was where everyone gathered to chat after Mass. But today, parishioners avoid the area like the plague.

The culprit: pinhead-size critters called redgum lerp psyllid that essentially destroy eucalyptus trees and leave a sticky mess in their wake.

“They sure hit us with a wham,” said Father James Rothe, pastor at the Santa Paula church where the pests have all but ruined the courtyard’s two prettiest trees.

Rothe is among hundreds of Southern Californians losing trees to the insidious lerps, an infestation that was the subject Wednesday of a regional pest-control summit.

Nearly 100 scientists, city officials and pest-control experts gathered at a Highland Park community center to swap information on the insect and discuss possible plans of attack.

Native to Australia, the bugs were first spotted a year ago in El Monte and have spread as far north as Sacramento and east as Phoenix. There are only two reported cases in Ventura County, but the insects reproduce and move quickly.

“It’s not a pest that you can stop. . . . We’ll see more and more in Ventura County,” said David Buettner, the county’s chief deputy agricultural commissioner. “We may see huge outbreaks of it.”

There are no natural predators in this country to keep the population under control. A UC Berkeley professor is slated to travel to Australia in the next few weeks to collect a breed of tiny wasps that feed exclusively on redgum psyllids.

It could, however, be months or even a year before the wasps--which pose no harm to humans--can be introduced legally to this country. It’s also unclear if the predators, which control the pests in Australia, will work here.

The psyllids primarily attack the leaves of red leaf eucalyptus trees, deplete them of moisture and cover them with honeydew. They reproduce, leaving behind their young in protected tiny white cones called lerps.

The eucalyptus trees usually don’t die but they are weakened and more susceptible to disease. The honeydew also drops onto yards, cars, driveways and patio furniture.

“I’m up to my you-know-what in redgum lerp psyllids--tons of them,” said Donald Hahn, a homeowner in Bell Canyon. “I’ve got enough for the whole county and we’re only talking about seven trees. And that sticky stuff is a pain.”

Since the critters took over his trees last month, Hahn has been forced to douse his driveway in water every other day to keep it from becoming a sticky, gooey mess.

Hahn’s 60-foot red leaf eucalyptus trees have been completely overtaken by the bugs, which can produce seven new generations every year, faster than most other insects.

“I’m just sitting here watching my leaves fall off,” he said. “There’s nothing I can do.”

Ladybug beetles, minute pirate bugs and a handful of other insects can be used to fight the psyllids, but there is no proof that they are effective, biologists say.

The Los Angeles Department of Recreation and Parks in May began a pilot program to fight the pest by releasing millions of ladybug beetles onto trees affected by the lerps.

Other cities and homeowners have experimented with spray-on or injectable insecticides, but the results are mixed. Still, homeowners and gardeners can do little to prevent a lerp invasion.

“Make sure they are watered and fertilized properly,” was Buettner’s advice to eucalyptus owners.

The psyllids don’t pose any health threat to humans but people like Hahn and Rothe say their trees may never be back to normal.

“It’s really too bad because those were two of the prettiest trees we had,” Rothe said.

Times staff writer Caitlin Liu contributed to this story.

Infesting Eucalyptus

The red gum lerp psyllid, native to Australia, has infested trees throughout Los Angeles County and the rest of the state.

DAMAGE TO TREES

The lerps are sticky and stain the ground underneath the trees. In severe infestations, thousands of lerps cover the ground, giving the appearance of fallen hail.

Sources: Rosser W. Garrison, Los Angeles County Agricultural Commission