Lerps of eucalyptoma maideni on spotted gym
Lerps are the protective covers made by nymphs of jumping plant lice or psyllids (Homoptera/Hemiptera, Family Psyllidae). Nymphs excrete honeydew on the leaf surface and the sugars and amino acids in the honeydew crystallise in the air to form lerps. Leaves can look black and sooty when sooty moulds grow on the honeydew. Lerp size and shape varies between species of psyllid.
Adult and nymph psyllids are both sap suckers and heavy infestations of nymphs can cause significant leaf-drop and defoliation in trees.
Creiis psyllid (Creiis lituratus) is an important pest of eucalypt plantations throughout coastal New South Wales to the Queensland border.
Glycaspis species and Cardiaspina species
Carnegie, A. and Lawson, S.A. and Smith, T. and Pegg, G.S. and Stone, C. and McDonald, J. (2008) Healthy hardwoods. A field guide to pests, diseases and nutritional disorders in subtropical hardwoods. Forest and Wood Products Australia, Victoria.
PaDIL - Pest and Disease Image Library
Pest Genie - current information on pesticides registered for use in forestry