Only the males have the comb-like antennae seen above. Their large surface area allows them to detect the pheromones of the females from afar.
The common name is descriptive of the larvae which are shown here.
Classification
from Australian Faunal Directory
Order Hymenoptera - Wasps, Ants, Bees and Sawflies, 12202 named species in Australia
Superfamily Tenthredinoidea - Sawflies, 161 named species in Australia
Family Pergidae - typical Sawflies, 140 named species in Australia
Genus Lophyrotoma
Species Lophyrotoma interrupta - Green Long-tailed Sawfly or Cattle Poisoning Sawfly