Entomologists from UC-Riverside and the California Agriculture Department “have launched a classical biological control program to reduce ACPs [Asian citrus psyllids] in the state’s urban areas,” says the UC Food Observer. The tiny psyllid help spread the devastating citrus greening disease, which results in bitter, misshapen fruit and eventually kills infected trees.
“They have imported from Punjab, Pakistan, two natural enemies of ACP, which attack different developmental stages of immature ACP,” says the Food Observer. The parasitoids have been released in California as a biocontrol of the psyllid, with promising initial results, according to UC-Riverside. The parasitoids have reduced psyllid populations by more than 80 percent.
It’s not a one-way struggle: The Argentine ant, also an invasive pest, “has developed a disruptive mutualism with ACP nymphs,” says Mark Hoddle, head of UC-Riverside’s Center for Invasive Species Research. “The nymphs provide honeydew, which is a sugar reward for the ants. In exchange, ants protect the ACP nymphs from their natural enemies. So, we’re working on new, novel ant control strategies. These might involve biodegradable baits loaded with ultra-low toxicity sugar water inside hydrogels made from crystallized algae.”