The red gum lerp psyllid, Glycaspis brimblecombei (Homoptera: Psylloidea; Spondyliaspididae) a new pest on California's eucalyptus trees, was discovered in 1998 in Los Angeles County and has since spread throughout much of the state. The psyllids are causing leaf damage and drop, which may stress trees and make them susceptible to attack by other insects. The psyllids also produce copious amounts of honeydew, which becomes a nuisance to cars and sidewalks below. In some areas a considerable number of trees have died.
We began a biological control program in the summer of 1998 by first developing a monitoring method and later importing, evaluating and releasing natural enemies. We have developed a monitoring technique with sticky traps that, based on two years of foliage sampling, adequately predicts psyllid activity on foliage (especially psyllid egg stage) by using adult female trap counts. We are currently sampling in thirteen counties of California at 26 sample sites. All of these areas have damaging levels of lerp psyllids, but the highest levels so far observed are in the Los Angeles area. In August of 1999 Dahlsten explored in Southeastern Australia for natural enemies of the lerp psyllid in three areas that are similar in climate to California coastal areas. Eight species of, Psyllaephagus (encrytid parasitoid wasps) were reared from lerp psyllid mummies in our quarantine facility at UC Berkeley. These wasps were tested for suitability as biological control agents against the lerp psyllid. One species (P. bliteus) has been found to be specific, not a hyperparasitoid, and effective in lab tests. Releases began in June 2000 at California field study sites. We have confirmed establishment at one site (Redwood City, San Mateo Co) and we are monitoring to evaluate establishment and effect on the psyllid population at other sites.
Species 1: Homoptera Psylloidea Glycaspis brimblecombei (red gum lerp psyllid)
Species 2: Hymenoptera Encyrtidae Psyllaephagus bliteus
Species 3: Eucalyptus camaldulensis (red gum eucalyptus)
Keywords: biological control, urban forest
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA