Illidge's Ant-blue Butterfly | Redland City Council

Illidge's Ant-blue Butterfly

Scientific name: acrodipsas illidgei

Other common names: Mangrove Ant-Blue Butterfly


  • Queensland: Vulnerable (NCA 1992)

What does it look like?

This is a small butterfly with a 22-24mm wingspan. The wings are mostly dark brown with black terminal lines on the upper side. The underside is pale brown with dark brown markings and black spots along the margins. Females have a large blue area in the middle of the body. A photo of this vulnerable butterfly can be found on the CSIRO wesbite.

Where is it found?

Illidge’s ant-blue butterfly only occurs in mangroves and adjacent areas along the east coast of Australia. A breeding population can only exist with the presence of ant colonies of the crematogaster (acrobat ant) species.

The larvae of butterfly prey on juvenile ants, while the ants feed on the larvae’s sugary excretions. The species’ survival is directly linked to the survival of ant colonies. These ants mainly inhabit the strands of mangrove avicennia marina and the bases of mistletoe plants parasitising Casuarina trees near the mangroves.

What is threatening them?

  • Increased clearance of mangrove areas
  • Increased use of pesticides.


Illidge’s ant-blue butterfly is protected under the Nature Conservation Act 1992. It is an offence to damage or interfere with Illidge’s ant-blue butterfly in any other way than when accepted by the Act.

Redland City Council manages environmental pests throughout the Redlands to minimise their impact on native ecosystems and animals such as Illidge’s ant-blue butterfly.

Did you know...?

The blue-coloured regions on females’ wings change shades depending on the viewing angle. 

Report your sighting

If you have seen or suspect you have seen a Illidge’s ant-blue butterfly, please report it to Atlas of Living Australia.