Regulators said one effect of the required treatments in the eradication zone is a likely blow to marketing of organic citrus. Because organic treatments have proven ineffective on the pest, Leavitt said, conventional sprays would be needed.

That, he said, would mean that the sprayed crop could not sold as organic. But, he said, it would not mean loss of certification for future crops because the spraying is mandated.

While CDFA is paying for spraying of residential trees in the zones, growers must pick up the tab for treating commercially grown citrus.

Leavitt said the Tulare County agricultural commissioner can use “abatement authority” for groves where treatment is not occurring, basically ordering that it be done at the expense of the landowner.

Beth Grafton-Cardwell, a University of California authority on treatment for the pest, said it is important that treatment be coordinated, swift and complete “to knock down outbreaks.” She said growers in Ventura County had to do additional spraying and faced other challenges because they “didn’t get control” and sprayed at different times.

Grafton-Cardwell, UC integrated pest management specialist and research entomologist, said different materials should be used depending on the timing of sprays. That’s because adults are most likely to be around in the winter, and the nymphs and eggs appear at other times.

A pyrethroid is recommended for the winter. It can also be used in the spring, followed by a soft insecticide. In summer, Grafton-Caldwell said, uptake of neonicotonoids is good and those should be combined with the pyrethroid.

Grafton-Caldwell also recommended sampling for the insect pest by using a white clipboard with a grid and knocking at branches of trees. She recommends sampling 10 trees on each of the borders of a grove and in 10 the middle. The psyllid prefers borders, she said.

She said it’s not best to rely solely on yellow sticky traps. While research is under way to improve traps, the insect is more likely to be drawn to volatile organic compounds from foliage than to the yellow traps.

Grafton-Caldwell said sprays that combat the pest can be timed with sprays that target others including thrips, katydids, peelminer, leafminer and scale.

Brian Taylor, director of field operations for the California Citrus Research Board, explained that the board is seeking to amass contact information for growers, pest control applicators, pest control operators, packinghouses and field operators in the restricted zones. He asks that they contact

HLB, the disease itself, has been found in only one tree in Hacienda Heights in Southern California. But it has been found elsewhere in places that include Florida, Texas, Louisiana, Georgia and South Carolina.

 Also called citrus greening, the disease kills citrus trees and there is no cure. Diseased trees produce lopsided, bitter fruit and eventually die.