Psyllids and lerps

Glycaspis psyllids or sugar lerps (Glycaspis species)

• Adults are around 4mm long from head to wing tips.
• Nymphs resemble wingless aphids; they enlarge the lerps or construct new ones as they grow.
• Lerps are:
  • squarish to conical
  • up to 5mm in diameter
  • usually white but sometimes yellowish or grey
  • often found on the upper surface of leaves along the midrib
• Sooty mould growth is often present.
• See additional images.

Cardiaspina psyllids or basket lerps (Cardiaspina fiscella and C. maniformis)

• Adults are up to 8mm long and winged.
• C. fiscella lerps are lacy and basket or shell-like, yellow-brown, mostly on lower leaf surfaces and mostly on mature foliage. Psyllid nymphs can be seen under the lerps if present.
• C. maniformis lerps are ribbed, scalloped, light yellow, mostly on upper leaf surfaces and mostly on mature foliage.
• Both lerps are 1–4mm long.
• See additional images.

Creiis psyllid (Creiis lituratus)

• Adults are orange, red or brown with mottled wings; they are strong flyers.
• Lerps are round or shell-like, 1–5mm long, smooth, opaque or semi-transparent.
• Lerps are found on both sides of leaves, but predominantly on the underside, and more commonly on older leaves.
• Nymphs can be seen under lerps if present.
• See additional images.

Spotted gum psyllid (Eucalyptolyma maideni)

• Adults are initially bright green, turning pale to yellow with age.
• Nymphs are bright yellow, reddish and then bright green as development progresses.
• Nymphs are usually mobile and are often seen outside the lerp.
• Lerps are white, flat and fern or feather-shaped.
• Lerps are typically 10mm long and 3–4mm wide.
• They are more common on the underside of leaves and on mature leaves.
• See additional images.

• Glycaspis psyllids – northern and south-eastern Queensland.
• Cardiaspina psyllids – throughout Queensland and Australia.
• Creiis psyllids – occur throughout coastal New South Wales to the Queensland border.
• Spotted gum psyllids – throughout Queensland where spotted gums are present.

Glycaspis species

• Rose gum and hybrids (Eucalyptus grandis)
• Gympie messmate (E. cloeziana)
• Blackbutt (E. pilularis)
• Red stringybark (E. resinifera)
• Swamp mahogany (E. robusta)
• Sydney blue gum (E. saligna)
• Red ironbark (E. sideroxylon)
• Forest red gum (E. tereticornis)

Cardiaspina species

• Rose gum and hybrids (Eucalyptus grandis)
• Swamp mahogany (E. robusta)
• Sydney blue gum (E. saligna)
• Forest red gum (E. tereticornis)

Creiis psyllid (Creiis lituratus)

• Dunn's white gum (E.dunnii)
• Grey gum (E.propinqua)

Spotted gum psyllid (Eucalyptolyma maideni)

• Spotted gum (Corymbia citriodora subspecies citriodora, C. citriodora subspecies variegata, C. maculata)
• Red bloodwood (C. gummifera)

• Glycaspis species do not usually cause direct damage to leaves, but they produce honeydew, which promotes the growth of sooty mould. However, large numbers can cause defoliation.
• Cardiaspina species cause the localised death of leaf cells around feeding sites, which initially turn red-purple and later brown. At high densities, the whole leaf becomes diseased and sheds.
• Creiis lituratus feeding produces reddish-purple leaf tissue that becomes diseased and brown, and often dies. High densities of lerps discolour the crown and can cause defoliation, tip dieback and sometimes tree death. This is an important pest of eucalypt plantations, especially E. dunnii plantations in New South Wales.
• Eucalyptolyma maideni is common on spotted gum but does not usually cause defoliation. High densities may encourage sooty mould growth.

Psyllids are naturally predated upon by a range of small birds and other insects. The eggs and nymphs are also parasitised by a range of wasp species.

Temperature and relative humidity affect the abundance of Glycaspis species. Low temperatures and high humidity were correlated with low psyllid numbers.

• Angel, P, Nichols, JD, Stone, C, 2008, Biology of Creiis lituratus Froggatt: (Hemiptera: Psyllidae), pest on Eucalyptus dunnii Maiden in plantations: morphology, life cycle and parasitism, Australian Forestry, 71(4):311–316, viewed July 2023.
• Carnegie, A, Lawson, SA, Smith, T, Pegg, GS, Stone, C, McDonald, J, 2008, Healthy hardwoods: a field guide to pests, diseases and nutritional disorders in subtropical hardwoods, Forest and Wood Products Australia, Victoria.
• Cuello, EM, López, S, Andorno, AV, Hernández, CM, Botto, EN, 2018, Development of Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae) on Eucalyptus camaldulensis and Eucalyptus dunnii Maiden, Agricultural and Forest Entomology, 20:73–80, viewed July 2023.
• Eatough Jones, M, Daane, KM, Paine, TD, 2011, Establishment of Psyllaephagus parvus and perplexans as serendipitous biological control agents of Eucalyptus psyllids in southern California, BioControl, 56:735–744, viewed July 2023.
• Jones, DL, Elliot, WR, Jones, SR, 2015, Pests, diseases, ailments and allies of Australian plants, Reed New Holland Publishers Pty Ltd, Chatswood, NSW.
• Sharma, A, Raman, A, Taylor, G, Fletcher, M, 2013, Nymphal development and lerp construction of Glycaspis (Hemiptera: Psylloidea) on Eucalyptus sideroxylon (Myrtaceae) in central-west New South Wales, Australia, Arthropod Structure & Development, 42:55–1564, viewed July 2023.
• State Forests of New South Wales, 1995, Psyllids in eucalypt plantations, Forest Protection Research Division Series Number E3.
• Pests and diseases image library (PaDIL)