Two University of Florida Institute of Food and Agricultural Sciences faculty discussed research that might offer future weapons in the fight against HLB-spreading Asian citrus psyllids (ACP). Both scientists made presentations at the recent Citrus Expo.
Bt toxins, which come from a bacterium, have been used to control pests in corn and cotton, said Bryony Bonning. “They don’t work terribly well, typically, against sap-sucking insects such as Asian citrus psyllid,” she said. Researchers hope to increase the Bt toxins’ efficacy against ACP using an approach “to increase toxin binding to the gut, which is the first step in having the toxin kill the insect,” Bonning said. Researchers must also find a good way to get the Bt toxins into the tree’s phloem so ACP can feed on it, she explained.
“It’s going to be a while” before Bt toxins are ready for control of ACP, Bonning said. “The Bt toxins are being developed as an additional tool to use in integrated pest management. There won’t be any one silver bullet for the problem.”
Another futuristic psyllid-control approach was presented by Nabil Killiny. “RNA interference (RNAi) is new technology where we can silence important genes in Asian citrus psyllid, causing mortality or inability to fly, and/or increase pesticide susceptibility,” a slide in his presentation stated. It continued: “RNAi is a promising and potential tool to control Asian citrus psyllid but is not ready yet for application in the field. Combinations of RNAi and other methods such as pesticide application or Bt-toxin could offer a very efficient control strategy.”
Growers and researchers focused heavily on controlling psyllids as a means of reducing HLB for years after the disease was discovered in Florida in 2005. Now that HLB is in virtually every grove in Florida, many growers have reduced their psyllid control efforts in recent years. However, most growers and researchers still consider psyllid control a vital part of the HLB management program.
Hear more from Bonning:
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