CRS degree day updates 2026

Biofix: March 1, 2026. 
First gen crawler emergence: April 12, 2026

As of April 24, Kern County is at approximately 721 degree days (base 53°F) from the March 1 biofix, indicating that first-generation California red scale crawlers are currently emerging, having surpassed the ~550 DD threshold. This is a key intervention window because crawlers are the most vulnerable life stage. Orchards should be actively scouted for white caps and crawler activity using double sticky tape traps on infested branches, checked weekly under magnification. Management should be based on confirmed field presence rather than degree days alone; if crawlers are detected, a well-timed treatment targeting this stage is warranted following UC IPM guidelines, with emphasis on good coverage and resistance management.

Second-generation male flight can be expected by May 25. If mating disruption is a part of your CRS IPM, and dispensers have not been already placed, place it before third week of May to target second generation flight. 

Click here for more information, comparing DD with previous season and 30-year average. Although biofix timed the same as previous season, first generation crawler emergence has been 3-4 weeks early in 2026. 

Individual field conditions may vary. Monitor Individual fields. For treatment recommendations UCIPM Guidelines for citrus