Keep Spraying Psyllids in HLB-Infected Groves

phil stansly

In a Citrus Expo talk, University of Florida Institute of Food and Agricultural Sciences entomologist Phil Stansly focused on the importance of continuing to spray psyllids in groves already infected with HLB. The main reason to do that, he says, is to keep psyllids from re-inoculating trees with HLB by “pumping more and more bacteria into that tree.” He says continuing to control psyllids gives the tree “a chance to recover, to produce some clean flush that can feed the roots and bring it back from the downward spiral into an upward spiral.”

Stansly says there are numerous ways for growers to reduce psyllid spray costs, including “not spraying when you don’t need to spray … allowing biological control to help us out … and avoiding resistance so we don’t have to increase our rates.”

He reiterates the long-held position of most Florida citrus entomologists that the winter dormant spray is the most important of the year. “What we’re trying to do there is prevent psyllids building up in the spring flush and flying out with a bunch of HLB and spreading it all over, which is what they do,” Stansly says. “In the summertime, I think we can probably slack up, maybe use oil, maybe skip a spray.”

He suggests that growers “use all the tools in the toolbox” in the effort to control psyllids. Killing the Asian citrus psyllids that spread HLB has been the single largest strategy growers have employed in the effort to control HLB. Most growers participate in citrus health management areas that coordinate sprays over large areas. In recent years, however, many growers have questioned the importance of continuing to spray for psyllids when all Florida citrus groves and most trees are already infected with HLB.

About the Author

Tacy Callies

Editor of Citrus Industry magazine