Grower Liaisons

The battle to save California citrus from the Asian citrus psyllid and Huanglongbing is a collaborative effort that involves local, county, state and federal officials, researchers, scientists and commercial citrus growers. To help facilitate pest management and disease eradication, the Citrus Pest & Disease Prevention Program has identified a program manager and key individuals in each region to be your point of contact.

Regional Grower Liaisons

Kern County – Judy Zaninovich
For questions or to receive periodic email updates with Kern County information, please email Judy at

Judy has enjoyed working with citrus growers on pest management issues since becoming a licensed pest control advisor (PCA) in 1984. For the past 10 years, she has coordinated treatments in citrus and grapes for the glassy-winged sharpshooter (GWSS) area-wide management program in Tulare County and North Kern County. Judy has helped in the reduction of the GWSS population to a smaller area of each county. She has also worked on a smaller project for the Tulare County Pest Control District to help protect the UC Lindcove Field Station from experiencing tree losses from the Tristeza Virus transmitted by aphids. In addition, she has managed the Consolidated Central Valley Table Grape Pest and Disease Control District since 2006. Judy has worked in close partnership with growers, PCAs, researchers and associated government agencies with the common goal of suppressing and eradicating these pests and their ability to vector devastating diseases. Judy received her bachelor’s degree from Cal Poly, San Luis Obispo and is a fellow of Class XXV of the California Agricultural Leadership Program.

San Bernardino, San Diego, Riverside and Ventura Counties – Sandra Zwaal
For questions or to receive periodic email updates with information for San Bernardino, San Diego, Riverside or Ventura County, please email Sandra at Please specify which region(s) your operations are in so that you may receive the proper updates.

Sandra is a licensed pest control advisor and a UCCE Master Gardener educating the public on pest and weed control, plant maintenance, Integrated Pest Management practices and water conservation. She also plans and executes school gardens on a project basis. After spending 15 years as a certified Project Manager Professional (PMP) in technology, public sector and finance, Sandra went back to school to obtain a bachelor’s degree in Agriculture/Plant Science from Cal Poly Pomona. While attending school, she managed a culinary farm where she grew seasonal food for The Restaurant at Kellogg Ranch on campus.

Santa Barbara, San Luis Obispo and Ventura Counties – Cressida Silvers
For questions or to receive periodic email updates with information for Santa Barbara, San Luis Obispo or Ventura County, please email Cressida at Please specify which region(s) your operations are in so that you may receive the proper updates.

Cressida Silvers did her undergraduate studies in plant sciences at Swarthmore College and earned her master’s degree in Entomology from University of California Riverside (UCR). She has more than 15 years of experience in agricultural pest management, research, demonstration and outreach in a variety of crops. Cressida spent five years as project coordinator of the United States Department of Agriculture Areawide Pest Management Project for the invasive Melaleuca tree in South Florida, working with public agencies and private landowners to increase awareness of the weed tree and to promote an integrated management approach based on biological control. Much of the remainder of her work experience has been in California agriculture. One of her first jobs was scouting for citrus pests in the Central Valley as an intern for Jim Gorden and Sylvie Robillard at Pest Management Associates. She worked on the Integrated Pest Management program for stone fruit pests at the Kearney Agricultural Research and Extension Center and did her graduate studies at UCR on biological control of avocado thrips. Most recently, Cressida worked as watershed coordinator for the Central Coast Agricultural Water Quality Coalition in Santa Barbara County, assisting fruit and vegetable growers with new water quality regulations.

Fresno and Madera Counties – Logan Henderson
For questions or to receive periodic email updates with information for Fresno or Madera County information, please email Logan at

Tulare County – Jessica Leslie
For questions or to receive periodic email updates with Tulare County information, please email Jessica at

Jessica Leslie is the owner of JML Consulting where for the last 10 years she has worked in the agriculture pest management field – specifically working with PCA’s and growers on area-wide treatment programs. An example of one of the area-wide treatment programs Jessica works on is the Tulare County Pest Control District’s Vector Suppression Program in Lindcove, CA. This program’s goal is to suppress the number of aphids available to transmit the Tristeza virus in citrus orchards surrounding the UC Lindcove Research Center in order to limit contamination of the center with the virus. Jessica works closely with the surrounding growers, PCA’s, and researchers on the station to coordinate treatments twice a year. As an aspiring 3rd generation PCA, the citrus industry has always held a special place in Jessica’s heart and ultimately guided her decision to pursue this career path. She resides in the small, close-knit community of Exeter, CA with her husband, two young sons and two rowdy dogs. Jessica is very excited for this opportunity to help local growers, as well as the citrus industry as a whole, on this extremely important program.