Second Asian citrus psyllid found in Rainbow

San Diego County’s Department of Agriculture, Weights and Measures was notified Aug. 17 that a second Asian citrus psyllid was found in Rainbow.

The North County finds for the week of Aug. 12 to 17 also include three additional Asian citrus psyllids in Valley Center.

“It’s extremely important for everybody to be aware and participate in the control of these psyllids,” said county agricultural commissioner Lisa Leondis. “Everybody has to be part of this control program.”

The additional finds may not equate to an infestation; after an initial find the Department of Agriculture, Weights and Measures (AWM) and the California Department of Food and Agriculture increase the density of traps and add traps in outlying areas.

“There’s a lot in South County, but it’s not affecting agriculture,” Leondis said of the psyllids.

A single Asian citrus psyllid can be a vector of huanglongbing disease which causes tree death, and a psyllid can carry huanglongbing disease from an infected tree to a previously-healthy tree.

“If there’s an infected tree the only solution is to remove that tree immediately,” Leondis said. “If they start to feed on the next tree it will bring that disease.”

In addition to the economic impact if huanglongbing disease spreads to agricultural orchards, backyard trees are also impacted. Leondis lives in Escondido and has backyard citrus trees, and she notes that such trees are an amenity to many San Diego County residences.

“I just so desperately want to protect that,” she said.

The entirety of San Diego County, other than some mountainous areas in the northeast portion, is currently blanketed under an Asian citrus psyllid quarantine.

“It’s okay to move clean citrus fruit. If there’re no leaves or stems and the fruit is clean, it’s okay to move,” Leondis said.

That allows growers of backyard citrus to bring the fruit to friends and relatives provided that the fruit only is transported and has been washed first. “Just make darn sure it’s clean,” Leondis said.

Growers of backyard citrus periodically trim their trees and place the stems and leaves in yard waste bins. AWM works with waste handlers to ensure that such green waste transport does not spread the presence of the psyllid.

“They have practices to make sure that stuff gets properly handled,” Leondis said.

“It’s the live plant moving that’s really the big risk,” Leondis said.

Purchasing a citrus tree from a nursery compliant with AWM procedures does not carry a risk. “Any of the host material for ACP (Asian citrus psyllid) is treated,” Leondis said. “If you buy from a reputable nursery, you’ll be okay.”

The first Asian citrus psyllid find in North County occurred in Valley Center in October 2009. A second psyllid in Valley Center was detected in August 2011. Another psyllid in Valley Center was found in July 2012. One psyllid has been found in DeLuz.

Leondis noted that unlike traps for fruit flies which use hormonal scents, no such specific attraction for psyllids is placed in traps. “They’re blender traps,” Leondis said.

“There’s nothing there to strongly attract them,” Leondis said. “It’s just a matter of luck to catch them.”

Leondis noted that citizen caution is critical to the battle against the Asian citrus psyllid.

“We definitely encourage people to be diligent,” she said.

“It’s not the pest du jour. It’s the pest that will end our crops and kill our trees,” Leondis said. “We really have to control these when they’re found.”