IPM Approaches to Reduce Psyllid Populations

Tacy CalliesCitrus, Psyllids

Adult Asian citrus psyllid
USDA/ARS photo by David Hall

Lukasz Stelinski recently shared integrated pest management strategies for reducing Asian citrus psyllid (ACP) populations to optimize tree health and yield. The University of Florida Institute of Food and Agricultural Sciences professor of entomology and nematology presented the information during the 2020 virtual Florida Citrus Industry Annual Conference.

Even with approximately 100 percent of Florida citrus trees infected with huanglongbing (HLB), reducing ACP populations can improve tree health and yield, Stelinski says.

According to Stelinski, since ACP populations and HLB are distributed throughout Florida groves, there isn’t a need to slow or prevent the spread of the disease. Now, it’s important to focus on management options.

Based on current research, reducing the presence of resident psyllid populations in citrus groves appears to help maintain tree health, even if the grove is periodically infested by ACP.

“Psyllid density is related to tree stress,” Stelinski says. The more psyllids are present, the greater the damage or stress on the tree, compromising its overall health.

He suggests growers use an integrated approach to most effectively minimize ACP populations. This includes using insecticides as well as cultural and biological methods.

During his presentation, Stelinski also discussed better alternatives for current ACP spray models. Currently, it is recommended that after harvest, a dormant spray is timed before major spring flush using a pyrethroid or organophosphate. Also, sprays are made on a schedule with intervals somewhat determined by length of efficacy of a particular insecticide.

However, Stelinski believes a better alternative is to spray for ACP adults at bud break at the beginning of each new flush before there is feather flush on which adults can lay eggs. He advises growers to apply a second spray on the flush as ACP begin to reappear, which seems to achieve more than 60 days of low ACP populations. He also recommends holding off spraying until ACP reach a threshold of 0.2 to 0.7 per tap sample.

Read more on ACP management.

Ashley Robinson, AgNet Media communications intern, wrote this article.