Website of Tobias Westmeier

Two-spotted Line Blue (Nacaduba biocellata)

Two-spotted Line Blue

Appearance: Very small. Undersite grey-brown with indistinct white lines and two subtornal black spots on the hind wing. Male upperside purple, female upperside brown with blue suffusion of varying extent.
Wingspan: 1.7 cm
Season: Several generations all year round.
Range: Widespread across Australia. Less frequent in TAS and in the far north of WA, NT, and QLD.
Habitat: Can be found in various habitats whereever the Acacia foodplants grow.
Photo: Male, Blue Mountains NP, NSW, 21/02/2010.

Description

The Two-spotted Line Blue is one of Australia's most widespread butterflies. With a wingspan of only 1.7 cm it is also one of our smallest butterflies and therefore not always easy to spot. Occasionally the adult butterflies can be found in large numbers flying close to the ground near the Acacia foodplants. They also commonly feed on flowers where they are easy to find and watch.

There exist a few similar species in the genus Nacaduba and Prosotas, in particular along the east coast of Australia. The Two-spotted Line Blue can be distinguished from these through its indistinct white markings on the underside that are much less prominent than in the other species. In addition, the Two-spotted Line Blue has two prominent subtornal black spots on the hind wing underside each of which contains a few iridescent green scales.

Additional Photos

Two-spotted Line Blue
The male upperside is mostly purple with two subtornal black spots on the hind wing. (Lesueur NP, WA, 11/08/2012)
Two-spotted Line Blue
The female upperside is brown with blue suffusion and two subtornal black spots on each hind wing. (Mundy Regional Park, WA, 28/07/2012)
Two-spotted Line Blue
The butterflies (here a male) are commonly found feeding from flowers. (Alice Springs, NT, 23/08/2009)
Two-spotted Line Blue
Underside of an older female with very prominent subtornal black spots. (Lane Cove NP, NSW, 31/01/2010)
Two-spotted Line Blue
Mating pair, with the female on the left-hand side. (Nambung NP, WA, 15/08/2010)
Two-spotted Line Blue
Adult butterfly resting on a shrub. (Nambung NP, WA, 15/08/2010)
Two-spotted Line Blue
The size of the subtornal black spots on the underside is variable. (Port Kennedy, WA, 16/10/2010)
Two-spotted Line Blue
The extent of the blue suffusion on the upperside of the female varies. (Yanchep NP, WA, 08/07/2012)