Nacaduba biocellata
In 3 days ~30% in a week ~60%
Nacaduba biocellata, the double-spotted line blue, is a butterfly of the family Lycaenidae. It is found in Australia (including New South Wales, the Northern Territory, South Australia, Victoria and Western Australia), Singapore, the New Hebrides, Sumba and Bali.
The wingspan is about 20 mm. Adult females have a brown upperside, while the males are blue with narrow black margins. The underside of both sexes is pale brown with light and dark wavy lines. The larvae feed on the shoots, flowers and buds of various Acacia species, including A. aneura, A. betchei, A. brachybotrya, A. deanei, A. erinaceae, A. irrorata, A. karroo, A. ligulata, A. osswaldii, A. penninervis, A. rigens, A. salicina, A. sclerophylla, A. sowdenii and A. victoriae. They can have a wide range of colours depending on their host plant, including pink, orange, yellow or green. They are attended by ants, mostly Iridomyrmex species, including I. purpureus and I. viridiaeneus.
Pupation takes place in a pale brown pupa. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Uluru-Kata Tjuta National Park | 🇦🇺 Australia | |
| 2 | Flinders Ranges National Park | 🇦🇺 Australia | |
| 3 | Hattah-Kulkyne National Park | 🇦🇺 Australia | |
| 4 | Ningaloo Marine Park | 🇦🇺 Australia |
With luck
About 10% of wildlife watchers report a Double-Spotted Line Blue sighting in Ningaloo Marine Park on a given day, based on 5 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 8th most-seen of the 13 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
April, July and September
In those months about 20% of wildlife watchers report a Double-Spotted Line Blue in Ningaloo Marine Park on a given day, against under 5% in June, August and October–March, the lowest months.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Double-Spotted Line Blue sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
4th of 4
Of the 4 parks where we can rate Double-Spotted Line Blue sightings, Ningaloo Marine Park ranks 4th at about 10%. The best odds are in Uluru-Kata Tjuta National Park (Australia, about 30%), Flinders Ranges National Park (Australia, about 20%) and Hattah-Kulkyne National Park (Australia, about 20%).
Same order: Lepidoptera
The closest relatives of the Double-Spotted Line Blue that you can see in Ningaloo Marine Park (order Lepidoptera, Butterflies and Moths) are Vine Hawkmoth (about 30%), Caper White (about 20%) and Lime Swallowtail (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Double-Spotted Line Blue is recorded against all the insects logged in Ningaloo Marine Park (5 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
