Second generation CRS crawlers have emerged!

Jun 28, 2024

Based on the CIMIS weather station data, we have enough degree days for the second generation of California red scale. Crawlers have started emerging.

Degree days as of June 27, 2024

Counties DD as of June 27 Next event What can you do
Kern 1641 Third gen. flight Treat in 1-2 weeks if necessary
Tulare 1733 Third gen. flight Treat in 1-2 weeks if necessary
Fresno 1551 Third gen. flight Treat in 1-2 weeks if necessary
Madera 1406 Second gen. crawler emergence Treat in 2-3 weeks if necessary

BMPs for CRS Management

  • 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.
  • Management choices for CRS – Mating disruption (CheckMate CRS), Biological control Aphytis melinus release; insecticides (Check UCIPM guidelines)  
  • Spray applications are most effective when populations consist of immatures and are synchronized. Spray as crawlers of the first or second generation are emerging. Expect first generation crawlers beginning this week in Kern, Tulare counties and in 1-2 weeks depending on location of your orchard.  
  • Plan for a thorough coverage (750-1000), drive <1.5 mph, except for Movento – apply at 250 GPA.

By Sandipa Gautam
Author - Cooperative Extension Area Citrus IPM Advisor

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