Researchers are testing the use of a fungus as a biological control agent to target the Asia citrus psyllid and citrus greening.

Researchers are looking to a naturally occurring fungusIsaria fumosoroseato act as a biological control agent against the Asian citrus psyllid, the insect vector that spreads citrus greening. According to a Citrus Industry article, the fungus had shown progress in lab testing, and researchers are now doing field testing. See the details below.

Fungus as a Biological Control Agent

The fungus showed promise in lab testing at the UF/IFAS Indian River Research and Education Center (IRREC) near Fort Pierce. IRREC researcher Pasco Avery maintained that “The fungus is not a panacea, but it is expected to greatly reduce the problem we have in managing the psyllid populations,” he said in the article. While the fungus is not a cure-all, it is a gentle treatment that could work in tandem with other treatments. “The fungus kills the psyllid but is compatible with beneficial insects like lady beetles, lacewings and parasitic wasps, which also control the psyllid,” Avery added.

Florida Research Center for Agricultural Sustainability, Vero Beach, director Bob Adair had the idea of using commercial sprayers and horticulture oils to distribute the fungus, according to the article, and he offered his groves as test subjects.

“Five years ago, Avery and I talked about how the fungus may enhance the effectiveness of horticultural oil sprays in controlling the insect in groves,” said Adair in the article. “Our work now is to add mass quantities of the fungus with horticultural oils that have been used in groves for decades and apply it to groves.” Avery added that, “what we found in the laboratory was that with the addition of the oils to the fungal suspension, it killed the insects faster and extended its efficacy.”

Spraying in the field trials occurred mid-June and again in September. The article reported that the initial spraying seemed to suppress psyllid populations for up to 14 days. “What we found with this first experiment was that the fungus was as effective as the active ingredient of the insecticide spinosad,” said Adair. “We tested the fungus for psyllid control, the effect on beneficial insects and resistance management. Now we need to conduct more tests to determine its effectiveness on a wider scale and time range.”