Last modified 2 Mar. 2005

Biological Control of psyllids on lemon-scented and spotted gum in California

Latest news - updated graphs of pysllid populations through 2004

Dr. Kent Daane, University of California at Berkeley, College of Natural Resources,

Center for Biological Control

And Dr. Timothy D. Paine, Department of Entomology, University of California, Riverside

© The Regents of the University of California, (2005)

Spotted gum psyllid adults, nymphs, and lerps on lemon gum foliage
Photo by John Schrimsher

In August 2000 two psyllid species were discovered on California's lemon-scented gum (Eucalyptus citriodora)and spotted gum (Eucalyptus maculata) trees at Disney Resort and surrounding areas of Anaheim, California. The psyllids, small insects that suck sap from leaves, are, like the eucalyptus, native to Australia. One is the spotted gum psyllid (Eucalyptolyma maidenii), a lerp psyllid, while another is the lemon gum psyllid (Cryptoneossa triangula Taylor), a free-living psyllid. They are causing leaf damage and drop which may stress trees and make them susceptible to fatal attack by other insects. Psyllids also produce a sticky substance called honeydew, which drops to the ground on cars and sidewalks.

In cooperation with Walt Disney Inc., the cities of Lakewood and Buena Vista, state and local agencies, University of California Extension units, and UC Exotic Pests and Diseases Research Program, we are monitoring these psyllid species populations, studying their biology, and are developing a biological control program using a natural enemy insect imported from Australia.

Natural enemies (imported by Don Dahlsten in 2002 and Kent Daane in 2004) are now under study at UC Berkeley's Insectary and Quarantine Facility. We hope to be able to release these natural enemy insects during the 2005 season.


| Population graphs |

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