Integrated Pest Management Update – April 21, 2026

Disclaimer: Pests/natural enemies’ activities and abundance updates provided on this site are for reference purposes only. Information provided here do not replace or supersede your orchard site-specific pest activity and abundance data. For optimal pest management decision support and treatment efficacy, use data and observations specific to your orchard.

See below the tables for additional information on traps and lures used for monitoring in these locations.

Butte County

Butte County pest monitoring report for Walnuts (4/16/2026), Almonds (4/16/2026)
Crop Insect First Biofix Second Biofix Third Biofix Fourth Biofix Activity (#/Trap/Day) Average Degree Days/Day Accumulated Degree Days from Current Biofix
Walnuts Codling Moth 3/25 0 8.74 235.86
Walnuts Navel Orangeworm (males) 0.04
Walnuts Navel Orangeworm (females) 0
Almonds Peach Twig Borer 3/25 0.7 8.74 235.86
Almonds Navel Orangeworm (eggs) 3/31 0.07 5.33 100.8
Almonds Navel Orangeworm (males) 0.14
Almonds Navel Orangeworm (females) 0.18

Tehama County

Tehama County pest monitoring report for Almonds (4/16/2026)
Crop Insect First Biofix Second Biofix Third Biofix Fourth Biofix Activity (#/Trap/Day) Average Degree Days/Day Accumulated Degree Days from Current Biofix
Almonds Peach Twig Borer 3/25 0.25 7.11 218.19
Almonds Navel Orangeworm (eggs) 3/25 0.02 3.94 154.78
Almonds Navel Orangeworm (males) 0.03
Almonds Navel Orangeworm (females) 0

Colusa County

Colusa County pest monitoring report for Almonds (4/13/2026)
Crop Insect First Biofix Second Biofix Third Biofix Fourth Biofix Activity (#/Trap/Day) Average Degree Days/Day Accumulated Degree Days from Current Biofix
Almonds Oriental Fruit Moth 3/25 0.31
Almonds Peach Twig Borer 3/19 0.88 9.6 373
Almonds Navel Orangeworm(eggs) 3/19 0 6 269
Almonds Navel Orangeworm (males) 0
Almonds Navel Orangeworm (males/females) 0.13

Sutter County

Sutter County pest monitoring report for Peaches (4/14/2026)
Crop Insect First Biofix Second Biofix Third Biofix Fourth Biofix Activity (#/Trap/Day) Average Degree Days/Day Accumulated Degree Days from Current Biofix
Peaches Oriental Fruit Moth 3/11 0.11 14.44 652.32

 

Additional pest management information is available at the UC IPM website, including a day degree calculator that can be tailored to your specific orchard location. Please contact Sudan Gyawaly at sgyawaly@ucanr.edu if you need more information on this report.

Activity (#/trap/day) represents the number of moths or eggs/trap/day for the 7-days from the most recent trap check date listed at the top of each data table.

Average degree days/day represents 7-day average degree day accumulations from the most recent trap check date listed at the top of each data table.

Codling moth traps in walnuts include plastic delta sticky traps (Suterra) baited with Suterra CM Biolure®.

Navel orangeworm (NOW) monitoring includes the following trap-lure combinations:

  1. Adult traps (delta sticky traps) for MALE moths are baited with Suterra NOW Biolure®.
  2. Adult traps (wing sticky traps) for FEMALE moths are baited with Peterson Trap Company bait bags.
  3. Egg traps (Suterra) are baited with Trécé Pherocon® NOW almond meal.
  4. Colusa orchard site also has NOW traps baited with PPO lures that catches males and females. Egg traps at this site are baited with almond meal + raw almond oil (3-10%)

Peach twig borer (PTB) traps in almond include plastic delta sticky traps (Suterra) baited with Suterra PTB Bioloure®.

Oriental fruit moth (OFM) traps in almonds and peaches include plastic delta sticky traps (Suterra) baited with Suterra OFM Bioloure®.

Note: established phenology (degree-day) models for NOW are based on egg trap data only currently.

We gratefully acknowledge financial support from the California Walnut Board, and the Almond Board of California.

Pest monitoring tools to monitor the pests mentioned in this report are manufactured by multiple companies. Mention of a brand name in this report is for educational purposes only and does not constitute recommendations or endorsement by the authors or the University of California.

Subscribe

Leave a Reply

Your email address will not be published. Required fields are marked *