Image: Stylops

Stylops

Stylops, line drawing. Stylops belong to the Order Strepsiptera.

Creator:
Andrew Howells
Rights:
© Australian Museum

Notes

What do stylops look like?

Size:
  • Wingspan of males 1 mm - 8 mm.
  • Body no more than 4 mm in length.
Body:
  • Widest at wing attachment (wide 'shoulders'), abdomen tapering.
  • Segment behind head of male small but segment bearing hindwings enlarged.
  • Females larvae-like.
  • Appears soft.
Antennae:
  • In males only.
  • Branched, antler-like and never longer than body.
Eyes:
  • In males only.
  • Berry-like, bulging or extended on short stalks, and well separated.
Mouthparts:
  • Reduced and non-functional.
Wings:
  • Two pairs (males only).
  • Forewings very small, club-like and hardened; no veins.
  • Hindwings broad, cape-like and with few veins and no cross-veins.
  • At rest, wings folded loosely over body though male stylops rarely rest.
Limbs:
  • Six legs.
  • Short and stocky.
  • Trochanter absent in fore- and midlegs.
Abdomen tip:
  • Cerci (tails) absent.

Where are stylops found?

  • Rarely sighted due to unique lifestyle.
  • Female stylops and their larvae can be found inside other insects especially wasps and bugs such as plant hoppers. They have also been found in cockroaches, silverfish, mantids, grasshoppers, other bugs, and flies.
  • Males, if you are extremely lucky, can be seen as they emerge from hosts, or whilst they are looking for mates adjacent to hosts.

What do stylops do?

  • Larval stages and female stylops of most families are internal parasites; adult males are free-living. In most cases they do not reduce the lifespan of the host significantly but are known to induce sterility.
  • Males are rarely found at rest, as they spend their brief adult life looking for females to mate with.
  • Adults do not feed.
  • Males are attracted to light.

What are the exceptions?

  • Females in the family Mengenillidae are free-living with eyes, legs and antennae females in all other families are legless, without eyes or antennae, and are parasites inside their insect hosts.

What looks similar?

  • Flies and Stylops can be easily confused. Unlike stylops, flies have a club-like hindwing and a fully functional membranous forewing.
  • Wedge-shaped beetles (Order Coleoptera, family Rhipiphoridae) are a lot like stylops. However they tend to be much larger and although their forewings are reduced they are never club-like in appearance. Females of wedge-shaped beetles are also, larvae-like and internal parasites but unlike stylop females they still retain legs.

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Tags stylops, insects, invertebrates, identification, Bugwise,