Home News Ag Economics Adding ACP-Effective Materials to Suppress Kern County HLB Vectoring Pest in Citrus

Adding ACP-Effective Materials to Suppress Kern County HLB Vectoring Pest in Citrus

ACP/HLB San Joaquin Valley Task Force – To Citrus Growers in the Kern County area: last fall and early this year, there has been a significant number of Asian citrus psyllid (ACP) trap detections (over 100) in Kern County. The detections occurred in residential properties, as well as commercial citrus areas in Kern County – especially the City of Bakersfield and areas south and east of it. Unfortunately, in addition to the trap detections, live breeding populations of ACP were discovered by CDFA survey crews in both residential and commercial citrus. Although these detection areas were treated, there is significant concern low level ACP populations may still exist undetected and left to build on the new spring flush. It is imperative for us to continue our efforts to protect Kern County citrus from the devastating effects of Huanglongbing (HLB) – especially in light of the significant level of HLB-positive citrus trees found just south in Los Angeles, Orange, San Bernardino and Riverside counties. An established population of ACP increases the threat of HLB but will also cause the need for additional insecticide treatments to try to suppress the population. Additionally, if HLB is detected and confirmed by CDFA, critical regulatory changes may affect everyone. Given the posed risks, it is important the San Joaquin Valley keep ACP populations as close to eradicated as possible.

The San Joaquin Valley ACP/HLB Area-Wide Task Force has been tracking and analyzing all ACP detections to date in Kern County. After recent review of the data, the Task Force strongly recommends growers add an ACP-effective material to their pre-bloom or spring foliar treatments – the sooner, the better since ACP build populations on the young leaf flush.  Fortunately, this timing coincides with pre-bloom treatments and treatments for katydid, worms, thrips and other pests.  See below for material examples from the University of California.

IMPORTANT: If there is any open bloom in the orchard, state bloom regulations and pesticide label pollinator protections must be followed.  Contact the Kern County Agricultural Commissioner’s Office for details at (661) 868-6300.


  1. Consider treating ALL your citrus blocks in Kern County, especially if they are located east and south of Bakersfield – including non-bearing trees and blocks not normally treated at this time.
  1. Use an ACP-effective insecticide next time you are treating the block. The sooner, the better – click on the link below for a list of ACP-effective insecticides from the University of California: Asian Citrus Psyllid / Citrus / Agriculture: Pest Management Guidelines / UC Statewide IPM Program (UC IPM) (ucanr.edu)

Examples of ACP-effective materials which also suppress Katydids (from the UCIPM Guidelines):

  • Danitol
  • Baythroid
  • Mustang
  • Micromite
  • Entrust

Examples of ACP-effective materials that can be used during the bloom period – some with restrictions (ALWAYS check the pesticide label and state bloom regulations prior to use):

  • Sivanto
  • Sefina
  • Micromite
  • Beleaf
  • Fujimite
  • ** = Restricted use to only 1 hour after sunset until 5 hours before sunrise.
  • **Delegate
  • **Entrust
  • **Exirel
  1. Suggested Dilution – 100 to 300 g.p.a. for airblast sprayers. FYI – many nutritional products are compatible with ACP insecticides however you should always check with your PCA before tank mixing.
  1. Please treat the borders of the block first, if possible, since ACP tend to populate block borders first. This way ACP will be driven toward the center of the block where they will get treated instead of away from the block and miss treatment.

By adding an ACP-effective material to your spring foliar treatment, we will greatly lower both the ACP population and the risk of HLB being transmitted into our trees. Please let me know if you have any questions or concerns regarding this important effort by the SJV ACP/HLB Area-Wide Task Force.

The ACP/HLB San Joaquin Valley Task Force

For additional information on Kern County operations, please contact:
Judy Zaninovich
ACP/HLB Grower Liaison for Kern County
(559) 730-8691

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