Eucalypt sawflies

• Sawfly larvae:
  • are similar to caterpillars with 3 pairs of legs
  • may be covered in short bristles
  • are tan to dark brown or black with a black head and a yellow to orange clasper at the tip of the tail, or light green with a black head and an orange clasper
  • are often seen in clumps of 10 or more on stems during the day
  • disperse and feed at night
  • when disturbed, raise their tails and regurgitate a yellowish fluid as a defensive mechanism.
• Adults can be up to 60mm long, are wasp-like in appearance and cannot sting, but are rarely observed.

Native to Australia and widespread across eucalypt forests and plantations from temperate to subtropical zones.

Sawflies have a wide host range including Eucalyptus, Melaleuca and Callistemon species.

• Damage to host trees is caused during the larval stage. The adult stage does not feed.
• Larvae are usually restricted to a small number of trees within a plantation and will often defoliate whole individual trees.
• Defoliation is common in plantations with establishing trees up to 6 years old. However, widespread defoliation is rarely observed.
• Single defoliation is unlikely to cause issues in establishing trees.
• Continued and extensive defoliation may lead to reduced vigour and undesirable form.
• Sustained defoliation may lead to tree mortality in rare instances.

• The adult female sawfly lays eggs in slits made between the upper and lower surface of a leaf or in tree bark. The slits are cut using a specialised ovipositor on the female’s abdomen.
• Eggs can take up to 2 months to hatch. Adults of some species guard the eggs until hatching.
• The larvae undergo 6 developmental stages. Each stage lasts 3–4 months.
• Young larvae graze leaf surfaces at first. When large enough, they eat entire leaves.
• At maturity, larvae pupate in the soil, or within wood or bark. Adults emerge sporadically.
• Male sawflies are uncommon; females can produce eggs without mating.
• Adult sawflies do not feed.

• Control is not usually necessary.
• Eggs are preyed on by small birds.
• Larvae are preyed on by larger birds at all life stages. Larvae are also parasitised by wasp species and tachinid flies.

• Carnegie, AJ, Lawson, SA, Smith, TE, Pegg, GS, Stone, C, McDonald, JM, 2008, Healthy hardwoods: a field guide to pests, diseases and nutritional disorders in subtropical hardwoods, Forest & Wood Products Australia, Victoria.
• Jones, DL, Elliot, WR, Jones, SR, 2015, Pests, diseases, ailments and allies of Australian plants, Reed New Holland Publishers Pty Ltd, Chatswood, NSW.