The Growing Threat of Asian Citrus Psyllid — How to Protect California Citrus from HLB

April 24, 2019

Hold the line against Huanglongbing

The Asian citrus psyllid (ACP), a vector of the bacterium that causes Huanglongbing (HLB) disease, has been spreading in California. Vigilant pest control is necessary to protect California citrus from the devastating effects of HLB.


HLB Can Be Devastating

Impact of ACP and HLB

HLB is the most devastating citrus disease worldwide and threatens all commercial citrus production. According to the USDA’s National Agricultural Statistics Service 2018 Annual Statistical Bulletin, Florida has lost 72% of its citrus production since 2010 as well as 175,000 acres of citrus trees and $314 million dollars since the rise of ACP. In the U.S., 5.6 million metric tons of citrus were lost due to ACP.

What’s at stake for California growers?

California represents 59% of U.S. citrus production with 265,000 acres of citrus producing $2.4 billion dollars value. According to California Citrus Mutual (CCM), infected trees have been found in Southern California and quarantine areas are growing2. Best management practices center around controlling ACP through use of insecticides and removing infected trees.

What's at Stake in California

How ACP Works in Citrus Plants

ACP damages citrus directly by feeding on new leaf growth (flush). More importantly, ACP is a vector of the bacterium, Candidatus Liberibacter asiaticus (CLa), which causes HLB and transmits the bacteria into the phloem when it is feeding on flush. The bacteria multiply in the tree’s phloem tissue, blocking the flow of nutrients through the plant. If not managed, citrus trees will die within 3 to 5 years. Effective control of ACP reduces the chance that a citrus tree will contract HLB and helps ensure a healthy, productive tree.

ACP Infographic

ACP and Insect Management from Bayer

Bayer has a proven insecticide portfolio that helps protect against citrus pests in California and provides the foundation for season-long ACP control. Using multiple modes of action and a range of application times and methods helps ensure crop quality and allows growers to stay ahead of HLB.

Nymph ACP Control

In a study on mature Valencia oranges, Roy Morris of Bayer in Fort Meade, Florida, showed that Movento® insecticide helped control nymph ACP by 92%.

Nymph ACP Control

Movento® helps control ACP by 92% with superior allover plant protection above and below ground.

Adult ACP Control

A trial conducted by Dr. John Curtis of Better Crops in Fort Pierce, Florida, showed that Sivanto® Prime insecticide helped control adult ACP by 93%.

Adult ACP Control

Sivanto® Prime helps control adult ACP by 93%, while preserving beneficials.

A University of Florida trial conducted by Dr. Michael Rogers in Winter Garden, Florida, showed that Baythroid® XL insecticide helped control adult ACP by 93%.

Adult ACP Control

Baythroid® XL helps control adult ACP by 93%.

Feeding Cessation of Adult ACP

Dr. Michael Rogers of the University of Florida in Winter Garden, Florida, also conducted a study that showed Admire® Pro insecticide and Sivanto® Prime insecticide caused a feeding cessation in adult ACP that reduced and prevented, respectively, xylem and phloem feeding and HLB bacterium transmission.

Feeding Cessation of Adult ACP

Admire® Pro and Sivanto® Prime caused immediate feeding cessation in adult ACP by 64.5% and 86.2%, respectively.

Proven Season-long Protection Application Timeline

For season-long protection, use Movento® at pre-bloom to help control ACP and red scale. At full-bloom, use Sivanto® Prime to help control ACP and citricola scale and to suppress citrus thrips. Using Admire® Pro at post-bloom promotes further protection against ACP and citricola scale. At fruit growth, Movento helps control ACP, and during harvest, Baythroid® XL helps protect against ACP, citrus thrips and katydids.

Multiple modes of action and a range of application times and methods helps ensure crop quality and helps growers stay ahead of HLB.

Proven Season Long Application Timeline


Protecting the California Citrus Industry

Bayer has partnered with California Citrus Mutual (CCM) to help prevent the spread of HLB and preserve the California citrus industry through the Abandoned Citrus Tree (ACT) Removal Program. Without monitoring, trees that neighbor a commercial grove could easily become a host and bring pests and HLB into an otherwise healthy area. The ACT Removal Program allows growers to identify and request removal of abandoned trees that can pose a threat to their groves.

The Bayer proven portfolio is a great cornerstone any insecticide program and helps ensure tree protection and productivity through season-long control of ACP and other key citrus pests.

Learn more about what the Bayer portfolio of insecticides can do for you. Click the product logos below.

Movento logo
Sivanto logo
Admire Pro logo
Baythroid XL logo

Read More About Managing Pests

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1 USDA’s National Agricultural Statistics Service Florida Citrus Statistics (2005/2006, 2015/2016 and 2017/2018 reports).