Dr. Sandipa Gautam, with the University of California, Agriculture and Natural Resources (UCANR), recently released the California Red Scale (CRS) Memo for 2025. The memo includes recent updates with links to field trials conducted on CRS in the last decade for more details. Below is a table summarizing the most recent CRS activities based on degree day accumulation, as of June 24, 2025.
UCANR Best Monitoring and Management Practices for CRS
Monitoring is key to managing this pest. To monitor for CRS:
- Pheromone cards for monitoring males, weekly or per flight.
- Leaf/twig sampling – sample the edge, interior or top of the tree. Determine if the scale is alive or dead by rubbing your thumb. Check for white caps and treat them within a week of first noticing them.
Management choices for CRS:
- Mating disruption (CheckMate CRS), Biological controlAphytis melinus release; insecticides (Check UCIPM guidelines)
- Spray applications are most effective when populations consist of immatures and are synchronized. Spray as crawlers when the first or second generation are emerging. Currently, second generation crawlers are emerging in Kern and Tulare counties, and in 1-2 weeks in Fresno County, and 2-3 weeks
- Plan for a thorough coverage (750-1000), drive <1.5 mph, except for Movento – apply at 250 GPA.
Articles are property of California Citrus Mutual. Please seek permission for use of content.
