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KAC Citrus Entomology
University of California
KAC Citrus Entomology

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Web Author: Dr. Beth Grafton-Cardwell, conducts research in the San Joaquin Valley on insect and mite pests of citrus. These web pages provide up-to-date information about the pests and their natural enemies, including basic biology, hosts, distribution, monitoring methods and management tactics. Please join us in exploring this subject through blogs, information and resources.

Citrus Bugs Blog

Degree Day Units Are a Bit Less Than Last Year

During 2014 and 2015, abnormally warm weather generated a rapid accumulation of degree day units, well above the 30-year average, that allowed an additional generation of California red scale to complete their development.  In addition, the excessively warm winters we have had during those years allowed California red scale, and other pests, to continue to develop during the winter in the San Joaquin Valley.  This is quite unusual.  While the 2016 season was well above the 30-year average through August, the accumulated degree day units at the end of the season were less than the last two years. Hopefully we will have a cold (but not freezing) winter that will prevent California red scale populations from continuing their development and cause mortality to the younger instars.



Posted on Monday, November 28, 2016 at 11:38 AM

New online course from UC IPM helps growers prevent illegal pesticide residues

The California Department of Pesticide Regulation (DPR) runs the most extensive Pesticide Residue Monitoring Program in the nation and is hard at work ensuring that the fruit and vegetables we purchase and consume are free from illegal pesticide residues.  Just last month, DPR detected residues of a pesticide not registered for use on grapes and fined the grower $10,000 for using a pesticide in violation of the label and for packing and attempting to sell the tainted produce.

Cases like this are rare in California but remind growers how important it is to apply pesticides correctly by following all pesticide label directions.  Understanding and following label instructions is the focus of a new online course developed by the University of California Agriculture and Natural Resources Statewide Integrated Pest Management Program (UC IPM).

Proper Pesticide Use to Avoid Illegal Residues is targeted to those who apply pesticides or make pesticide recommendations.  It explains what pesticide residues are, how they are monitored, and highlights important residue-related information from several sections of pesticide labels.  In addition, the course identifies the following as the most important factors leading to illegal residues:

  • Using a pesticide on a crop or against a pest for which it is not registered
  • Applying pesticides at an incorrect rate
  • Ignoring preharvest intervals, re-treatment intervals, or plantback restrictions

Course participants are presented with several real-life scenarios.  They must search through actual pesticide labels to determine if the scenario illustrates proper use of pesticides or if the described situation could potentially lead to illegal residues.

The overall goal of this course is to have participants follow pesticide label instructions when they return to the field.  Following the label can eliminate incidences of illegal pesticide use.


Posted on Friday, October 28, 2016 at 11:34 AM

Citrus Entomology Staff Present at Woodlake Highschool Career Day

Sara Scott and Joshua Reger, Staff Research Associates with the Dept of Entomology, UC Riverside are stationed at the Lindcove Research and Extension Center.  Their research program centers on citrus integrated pest management.  On October 14, they presented information about citrus fruit and citrus pests for Woodlake High School career day and talked to students about their careers in agricultural research.

Posted on Monday, October 17, 2016 at 9:12 AM

Citrus Thrips Field Day at Lindcove REC Was a Success!

On Sept 13, a field day was held at Lindcove Research and Extension Center to discuss citrus thrips biology and management.  We utilized the mobile laboratory for a powerpoint presentation and to support microscopes that showed various stages of citrus thrips and flower thrips.  We also visited a pesticide spray trial to talk about efficacy of various pesticides.

Take home messages: 

  • The immature stages of citrus thrips are the most damaging
  • In mature trees, protect fruit not foliage
  • In young trees, be careful of spraying too much or you will select the thrips for resistance
  • Thrips are tough to control in drought years

The entomology lab at Lindcove is going to start monitoring for resistance this fall.
If you have sites that have thrips that you would like tested, contact Joshua Reger

Posted on Friday, September 23, 2016 at 7:33 AM

Be Prepared for Changes to the Worker Protection Standard

The United States Environmental Protection Agency (U.S. EPA) recently published the revised Agricultural Worker Protection Standard (WPS).  The WPS is meant to increase protections for agricultural fieldworkers and pesticide handlers from pesticide exposure when working in farms, forests, nurseries and greenhouses. The changes will definitely affect California agriculture, and soon-- as early as January 2017 in some cases.

What major regulatory changes are in store for us and when will they happen?

Several changes are required to be in place by January 2, 2017. These include:

  • All 417,000 fieldworkers in California must attend annual pesticide safety training.
  • Records of all fieldworker pesticide safety trainings must be kept on file for 2 years.
  • Fields must be posted when the restricted entry interval (REI) exceeds 48 hours.
  • Instructors previously certified via Train-the-Trainer to lead pesticide safety trainings must now attend an EPA-approved Train-the-Trainer course to maintain that certification.

 The regulatory changes that are required to be in place by January 2, 2018 include:

 Additional training topics for fieldworkers and handlers must be added to the curriculum.

  • “Application-exclusion zones” must be implemented to prevent the entry of anyone into areas up to 100 feet from pesticide application equipment. Application-exclusion zone regulations also require handlers to suspend an application if anyone enters the restricted area.

Who do these changes affect?

Many people who work in the California agricultural community will be impacted by the WPS revisions including fieldworkers, pesticide handlers, farm labor contractors, private and in-house safety trainers, growers, farm managers, licensed pesticide applicators (private and commercial), pest control advisors (PCAs), and crop consultants to name a few.

 The new changes bring about a shared liability with all those involved in employing or training fieldworkers and handlers.

How can I get qualified as a trainer?

To become a trainer, take an EPA- and DPR- approved Instructor Training (a.k.a. “Train-the-Trainer”) workshop.  The University of California Pesticide Safety Education Program (part of the UC Statewide Integrated Pest Management Program, UC IPM), in partnership with AgSafe, will offer multiple workshops this fall that cover the new federal requirements for fieldworker and handler training.  Visit the Events and workshops page on the UC IPM website to reserve your spot.  At the end of the training you will be a certified pesticide safety instructor. 

Remember, even if you've already participated in a Train-the-Trainer workshop, you are required by EPA to retake the program unless you maintain certain licenses/government designations, including PAC, QAC, QAL, PCA, and certain County Biologist licenses.  UCCE Advisors are also exempted from the need to retrain.

If I am currently qualified, how can I make sure I stay up to date on all these new requirements?

If you are currently qualified as a trainer because you maintain a California PAC, QAC, or QAL, or if you are a PCA, you can attend a Train-the-Trainer workshop this fall to learn about the new WPS requirements and additional training topics.  While a certification may qualify you, a Train-the-Trainer Workshop will prepare you to train! Register today.


Posted on Thursday, September 15, 2016 at 8:09 AM
  • Author: Lisa Blecker
  • Author: Sarah Risorto
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