Eucalyptus weevils

Gonipterus weevils

• Adults:
  • grow up to 14mm long
  • are brown, dark red-brown or grey-brown, and sometimes striped
  • have a smooth dorsal surface
  • disperse readily and are active during much of the year.
• Larvae:
  • are up to 10mm long and slug-like
  • are yellow to orange with small black spots on the back and black stripes on the sides
  • may have a thin thread of excrement coiled up or trailing behind them
  • are often slimy when older.

Oxyops weevils

• Adults:
  • grow up to 14mm long
  • are brown or grey-brown, with blotches and mottles
  • have a rough dorsal surface.
• Larvae:
  • are up to 10mm long and slug-like
  • are black
  • may have a thin thread of excrement coiled up or trailing behind them
  • are often slimy when older.

See additional images of eucalyptus weevils.

Widespread across Australia, including temperate and subtropical zones.

Gonipterus weevils

• Spotted gum (Corymbia citriodora subspecies variegata)
• Dunn’s white gum (Eucalyptus dunnii)
• Southern blue gum (E. globulus)
• Rose gum (E. grandis)
• Grey gum (E. propinqua, E. punctata)
• Swamp mahogany (E. robusta)

Oxyops weevils

• Broad-leaved paperbark trees, including:
  • Melaleuca cajuputi
  • M. dealbata
  • M. leucadendra
  • M. quinquenervia
  • M. viridiflora.

Oxyops vitiosa has been used as a biological control agent for M. quinquenervia in Florida, where it is an invasive tree.

• Larvae feed on the upper surface of emerging leaves, leaving characteristic tracks resembling long, thin windows or holes, which enlarge as the leaf grows.
• Damaged areas turn brown and the leaf falls early.
• Older larvae will consume entire leaves.
• Adults mainly feed on leaf edges, leaving ragged or scalloped patterns.
• Adults can also feed on the soft bark of young shoots.
• Feeding results in retarded growth and shoot dieback.
• Successive defoliation events cause a deformed appearance and the growth of epicormic shoots.
• Sustained attack can reduce tree vigour and cause decline or death in young trees.
• Mature trees are not badly affected.

• Eggs are laid in batches within a capsule that is attached to leaves.
• Larvae moult several times before falling to the ground to pupate in the soil.
• There are usually 2 or 3 generations per year, depending on the temperature.

• In Australia, natural predators reduce weevil numbers, so control is not usually necessary.
• The Australian parasitic wasp Anaphes nitens has reduced the impacts of weevils in eucalypt plantations overseas.

• Australian Pesticides and Veterinary Medicines Authority (APVMA)
• 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 & Wood Products Australia, Victoria.
• Purcell, MF, Balciunas, JK, 1994, Life history and distribution of the Australian weevil Oxyops vitiosa (Coleoptera: Curculionidae), a potential biological control agent for Melaleuca quinquenervia (Myrtaceae), Annals of the Entomological Society of America, 87:867–873, viewed Aug 2023.