Hymenoptera Click to enlarge image
Sawfly (Order Hymenoptera, suborder Symphyta) Image: Andrew Howells
© Australian Museum

Sawflies belong to the Sub-order Symphyta in the Order Hymenoptera.

What do sawflies look like?

Size:

  • 3 mm - 55 mm in length.

Body:

  • Stout, column-like to cigar-shaped, lack constriction at 'waist'.
  • Appears hard.

Antennae:

  • Short and varying in form from thread-like to feather-like.

Eyes:

  • Large and well separated.

Mouthparts:

  • For cutting and munching.
  • Held downwards at rest.

Wings:

  • Two pairs.
  • Both pairs are membranous and clear; veins form cells with at least one vein extending to margin of wing.
  • Hindwing always shorter and narrower than forewing.
  • Fore- and hindwing coupled tightly by a row of minute hooks (hamuli) along adjacent edges.
  • At rest wings held flat along body, and overlapping or resting above the body on special pads (cenchri).

Limbs:

  • Six legs, slender; hindlegs of some species have enlarged 'thighs' for jumping.

Abdomen tip:

  • Saw-like ovipositor (no sting) sometimes visible but often folded into a groove, much like a pocket knife.

Where are sawflies found?

  • On vegetation.

What do sawflies do?

  • They are solitary, though their larvae better known as spitfires can be found in large groups.
  • When disturbed they fly away, jump, act aggressively like a wasp or in the case of their larvae dispense noxious secretions.
  • They hold their antennae in front of body at rest.
  • They are strong fliers and buzz loudly when they fly.
  • Adult sawflies mostly feed on nectar and do not provide food for their young. Females of some species guard eggs and young larvae.
  • They use their saw-like ovipositor to saw into vegetation such as leaves to deposit their eggs inside. The larvae feed on internal tissue of plants.
  • Species of the sawfly family Orussidae are parasites of beetle larvae.
  • They are active during the day.

What looks similar?

  • Wasps are closely related to sawflies (in the same Order) and so share many common features. Wasps can be separated from sawflies as they have a distinct waist, and their wings have few veins or if they have complete cells then the veins never extend to the margin of the wing. They also tend to have a spike like ovipositor/sting and some have long antennae.
  • Bees are closely related to sawflies (in the same Order) and so share many common features. Bees can be separated from sawflies by their hairy bodies, hindlegs with enlarged 'shins' forming baskets of hairs for carrying pollen. Bees also have a distinct 'waist' but as some bees are very hairy this 'waist' may be difficult to see.
  • Ants are closely related to sawflies (in the same Order). Some species of parasitic sawflies (family Orussidae) are remarkably ant-like in appearance and behaviour. Their forewing is even patterned in a manner which, at rest, gives the impression of a constricted 'waist'. In general the following features distinguish ants from sawflies: constricted 'waist' with one or two knobs; antennal segment closest to body very long (5x as long at least) to any of the remaining segments; presence of certain glands (microscope and taxonomic expertise required).