Narrator:        This is Science Today. The California Department of Food and Agriculture is ramping up its eradication and quarantine efforts to control the spread of the Asian citrus psyllid, a tiny pest that's considered a dangerous threat to California citrus groves. The psyllid, which is the carrier of a deadly bacterial plant disease, has already caused billions of dollars in damage to Florida's citrus industry. University of California citrus researcher Beth Grafton-Cardwell describes what Californians with citrus trees should look for.

Grafton-Cardwell:      You will see damaged leaves, especially on new foliage. You'll see sometimes sooty mold, this sticky stuff that aphids and psyllids produce and you'll see small orange-ish yellow nymphs and those little white tubules that they produce on their bodies.

Narrator:        So far, psyllids have been detected in three southern California counties and packages with the insect were recently intercepted in both Central and Northern California. Grafton-Cardwell says none of the insects trapped had the disease, but she's working with state and federal agencies to control an infestation. For Science Today, I'm Larissa Branin.