In the fall of 2009 a citrus pest called the Asian Citrus Psylid showed up in our neighborhood. It’s a major concern to commercial citrus growers since the pest spreads an incurable and fatal plant disease called huanglongbing (HLB).
The California Department of Food and Agriculture commenced a futile effort to suppress the psylid by hiring a contractor, TruGreen, to spray residential backyards in Southern California with a combination of imidacloprid (deadly to pollinating insects) and pyrethroid.
As I expected, it didn’t work. The state’s strategy has now shifted to releasing a parasitic wasp (Tamarixia radiata) imported from Pakistan. Citrus farmers will continue heavy applications of pesticides to keep the psylid at bay. UC Cooperative Extension biological control specialist Mark Hoddle explained to KQED (italics mine),
Hoddle says Tamarixia radiata won’t eradicate Asian citrus psyllid. Commercial citrus producers in California will still continue to apply insecticides to prevent the spread of Huanglongbing. But, he says, state regulators have already determined backyard pesticide applications are too expensive ($10-11 million so far) and too ineffective to bother with.
Frankly, I’m inclined to conclude that the original eradication program was a make-work program for CDFA officials and TruGreen all made possible by a big infusion of cash from our tax dollars and the citrus industry.
During their backyard spraying campaign in our neighborhood in the fall of 2010, the CDFA and TruGreen showed up at a neighbor’s house who, at the time, had over 50 citrus trees in pots (she was operating a mini-nursery and selling the trees). CDFA and TruGreen were overwhelmed by the amount of trees and ran out of imidacloprid. They promised to return but never did, leading me to believe that they weren’t really interested in eradicating a pest but were, instead, engaged in a kind of “pesticide theater”. It’s a bit like the security theater that goes on everyday at our nation’s airports courtesy of the TSA.
Even with the parasitic wasps I’m not planning on planting any citrus or recommending that citrus be planted in Southern California backyards. Everywhere in the world the psylid has shown up, HLB has followed within a decade. I strongly suspect that growing citrus in SoCal will be like trying to grow table or wine grapes here. With grapes, Pierce’s disease, spread by a very similar insect called the glassy winged sharpshooter, makes it impossible to grow anything but resistant varieties unless you use a lot of pesticides. Until a HLB resistant citrus tree shows up (probably by means of genetic modification, never a great option IMHO) I’d stick to pomegranates and figs.
