KAC Citrus Entomology
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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

Updated Asian Citrus Psyllid Pest Note to Share with Friends


The recently updated Asian citrus psyllid pest note is a great publication to share with friends and family.  It describes the history, biology and management of Asian citrus psyllid and the huanglongbing bacterial disease of citrus it can transmit.  It provides excellent photos for identifying the insect and disease symptoms.  You can download the publication from the UC IPM web site: Asian citrus psyllid publication 74155.

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Posted on Thursday, October 11, 2018 at 2:37 PM
Tags: acp (1)

National Honey Bee Day 2018: Brush up on your knowledge of bee protection

Celebrate National Honey Bee Day by brushing up on your knowledge of bee protection—check out the newly revised Best Management Practices to Protect Bees from Pesticides and Bee Precaution Pesticide Ratingsfrom UC IPM. These resources will help you strike the right balance between applying pesticides to protect crops and reducing the risk of harming our most important pollinators.   

The best management practices now contain important information regarding the use of adjuvants and tank mixes, preventing the movement of pesticide-contaminated dust, and adjusting chemigation practices to reduce bee exposure to pesticide-contaminated water. The Bee Precaution Pesticide Ratings have also been updated to include ratings for 38 new pesticides, including insecticides (baits, mixtures, and biological active ingredients), molluscicides (for snail and slug control), and fungicides.

Most tree and row crops are finished blooming by now, but it is a good idea to learn about bee protection year-round. Visit these resources today to choose pesticides that are least toxic to bees and learn how you can help prevent bees from being harmed by pesticide applications.


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honey bee on citrus

honey bee on citrus
honey bee on citrus

Posted on Thursday, August 16, 2018 at 8:04 AM
  • Author: Stephanie Parreira

Summer—it’s a time for swimming, BBQs, camping, and eating invasive species


Last week during California Invasive Species Action Week (June 2 – June 10), we highlighted several pests, but there are many more invasive species out there. Now that you know about them, share your knowledge of invasive species with others. And no matter what your summer plans, here are some things YOU can do about invasive species from the California Department of Fish and Wildlife and California Department of Food and Agriculture. 






  • Get to know your local invaders.
  • Learn about California's invasive plants.
  • Find out which species are threats to California.
  • Learn alternatives to releasing unwanted fish, aquatic plants, and other pets.
  • Eat them. Yum. Check out these websites to find out who is edible and how to prepare them.

If you missed it this year, help in the fight next year by learning and participating during California Invasive Species Action Week.


Posted on Friday, June 15, 2018 at 7:42 AM
  • Author: Tunyalee Martin

Italian White Snail Slowly Becoming an Invasive Pest (Again)


Sometimes an invasive pest takes a while to become invasive. The Invasive Species Council of California defines an invasive species as “non-native organisms which cause economic or environmental harm.” So, until a species not originally from the area actually causes harm, it doesn't get the title of invasive.

Take the Italian white snail, also known as the white garden snail. In San Diego, it caused extensive damage to agricultural plants in the early 1900s but was considered eradicated after a massive control program in the 1920s. However, it was found again in San Diego County in the 1980s but it did not damage agricultural crops or gardens. Instead the snails lived off of weeds in neglected fields. Now it appears to be moving slowly from these fields to fruit tree orchards and avocado groves as well as landscapes. The Italian white snail feeds on decaying organic matter and living plants, damaging leaves, flowers, and fruit. Another fear is it being found in cut flower growing areas or in nurseries where it could become an export issue.

White or light tan, the Italian white snail is about the size of a dime or nickel when fully grown. It may or may not have brown markings on the outside of the shell. The inside shell color near the opening is light colored (compared to the milk snail, which looks similar but has a dark inside shell). Italian white snails are most noticeable during the day and when it is hot, because the snails climb up on fence posts, walls, weeds and other vegetation and congregate in large numbers.

In California, the Italian white snail is only officially found in San Diego County. However, it could easily move to new areas because of its small size, which makes it hard to detect, and tendency to attach to many kinds of surfaces such as truck beds. Also, because land snails are hermaphroditic—each snail has both male and female reproductive organs—it only takes any two snails to reproduce!

Californians can help in the fight against invasive species by learning and participating during California Invasive Species Action Week, June 2–10.

Posted on Friday, June 8, 2018 at 11:04 AM
  • Author: Tunyalee Martin
  • Author: Cheryl Wilen

Invasive species…not very a-peel-ing


Citrus plants can be hosts for invasive pests. Knowing what pests are invasive and how to avoid them is an important part of nursery production. If you work in a citrus nursery, you play an important role in looking for invasive pests and protecting the nursery—and ultimately California's citrus industry—from invasion.

Your mission, should you choose to accept it, is to prevent invasive pests and their harmful impact to agriculture. When pests or diseases are new to an area, we call them invasive. Many of the laws that are in place for citrus are to prevent new pests and diseases from establishing.

Citrus nurseries that become infested with new pests may be quarantined until the infestation is gone, preventing the plants from being moved or sold. Sometimes it requires the plants to be destroyed. Sometimes it results in the loss of a business.

You might have heard of some these invasive pests in California citrus—diaprepes root weevil, light brown apple moth, and red imported fire ant. Some invasive pests are diseases carried by an insect such as citrus variegated chlorosis spread by glassy winged sharpshooter, brown citrus aphid in Florida and Mexico making citrus tristeza even more problematic, and huanglongbing spread by Asian citrus psyllid.

Learn more about these invasive pests and how to stop their invasion by viewing an online training for workers of citrus growing in protective structures by UC Cooperative Extension Specialist Beth Grafton-Cardwell. Citrus Nursery Protective Structure Worker Training provides information on growing healthy citrus plants in structures and protecting them from common insect pests and diseases, including invasive ones in Chapter 3. You can also find on UC IPM's online training webpage, training about Asian citrus psyllid and huanglongbing for retail nursery personnel and for UC Master Gardeners.

When pests first arrive in California, an effort is made to detect them by searching the plants and by trapping for them.  It is important for you to be a detective and help in this effort:

  • Watch for anything unusual and report anything new.
  • Keep yourself and anything you work with in the protected structure clean, disinfected and free of pests.
  • Keep the protective structure sound by fixing holes in screens, gaps in the structure, and unprotected vents.
  • Use good practices in the nursery such as planning your day to start indoors and finish outdoors so that you don't bring outdoor pests inside.
  • Don't bring in pests from other areas in budwood or fruit.

Californians can help in the fight against invasive species by learning and participating during California Invasive Species Action Week, June 2–10.

During the week, spend your lunch with us learning the latest about invasive tree killing pests, aquatic nasties like quagga mussels and nutria, and how the invasive weed/wildfire cycle is altering our ecosystems! http://ucanr.edu/sites/invasivelunch/

Worker managing citrus in a protective structure

Posted on Monday, June 4, 2018 at 3:53 PM
  • Author: Tunyalee Martin
  • Contributor: Beth Grafton-Cardwell
Webmaster Email: eegraftoncardwell@ucanr.edu