Citrus quarantine expanded to stop spread of citrus tree disease

REDLANDS, Calif. — Following the detection of Huanglongbing (HLB), a serious citrus disease, a quarantine has been placed on counties throughout Southern California, including San Bernardino. 

Why it matters: This quarantine comes just as Redlands is undergoing mandatory fruit removal to eradicate the oriental fruit fly. Both the removal and expansion of the quarantine zone signify efforts to contain the spread of harmful insects and diseases that put the region's citrus industry at risk. 

Details: The California Department of Food and Agriculture (CDFA) announced the quarantine, which, according to their interactive map, encompasses San Bernardino, Riverside and Los Angeles counties. 

HLB, also known as citrus greening disease, is transmitted by the Asian citrus psyllid, an invasive insect no bigger than a grain of rice that can have devastating impacts on crops. Signs that a tree is infected include yellowing leaves, misshapen fruit and eventual tree decline. While the disease isn’t harmful to humans, once a tree is infected, there is no cure. 

The first Asian citrus psyllid sighting in California was in 2008 in San Diego. HLB was first found in San Bernardino County in November of 2019. 

Zoom out: It is estimated that 6 out of every 10 residences in California have at least one citrus tree, which is why it is important for everyone to do their part to minimize the spread. This disease can be disastrous in areas known for citrus production. Since 2005, Florida has seen more than a 70% reduction in orange crops due to HLB, says researchers from Florida International University. 

Moving forward: For those living within the quarantine zone who have citrus trees on their property, it is prohibited to move any fruit or plants outside of the area. This includes oranges, lemons, grapefruits, and kumquats.

While the fruit cannot be moved from the property it was grown on, it still can be processed or eaten onsite.

Residents should also cooperate with agricultural officials, placing traps, inspecting trees and treating for the pest. 

To see if your property falls within the quarantine zone, click this link to see the CDFA’s interactive map.