Larvae are found beneath these lerps or bumps they have built. Both adults and especially larvae suck sap from the leaves and stems thus weakening Redgums. RLP produces large amounts of sticky clear liquid called honeydew which stains the ground beneath trees. A blackish sooty mold grows on the honeydew-covered surfaces. The lerps and honeydew stick to shoes and dirty cars, buildings and sidewalks.
Heavy infestations are even more harmful causing leaf drop and severely stressing trees.
RLP was introduced into California before 1998 without these natural enemies. RLP has become abundant in California because its favored host plants, certain species of eucalyptus trees, are commonly grown over much of California. Biological control for RLP offers the best hope for controlling this pest. On Wednesday, June 7, Dr. Donald Dahlsten, Center for Biological Control, University of California, Berkeley began an RLP biological control program by releasing a species of small parasitic wasp in Valley Village area of Los Angeles. This will be followed by field releases on a weekly basis at other monitoring sites in the county.