Ants can be a huge nuisance in and outside our homes, particularly if you have food lying around. But now, it turns out, they’re unwelcome, too, on citrus trees.  

A year ago, UC Riverside entomologists released Tamarixia, a parasitoid wasp and natural enemy of the Asian citrus psyllid (ACP) imported from Pakistan, into a biocontrol grove in Riverside, Calif. Tamarixia can serve as an excellent biocontrol agent against ACP, a citrus pest first detected in 2008 in Southern...