Nacaduba pactolus
In 3 days ~20% in a week ~30%
Nacaduba pactolus, the large four-line blue, is a species of lycaenid butterfly found in Indomalayan realm. A very variable form both in the shade of the ground colour on the upperside and in the width, and more or less in the arrangement also of the transverse white lines that cross the wings. Typical male: upperside: deep purplish brown with a curious minutely granular roughened appearance; in certain lights the purple shines with iridescent blue tints. Forewings and hindwings: uniform; both with slender anteciliary black lines; on the hindwing the black spots on the tornal angle on the underside show through by transparency. Cilia brownish; filamentous tail at apex of vein 2 on the hindwing black tipped with white. Underside: brown with a slight silky lustre. Forewings and hindwings: with the following transverse, more or less broken, slender, dull whitish bands: two short bands, one on either side of the discocellulars; a discal pair, the posterior portion below vein 3 shifted inwards, thus forming the stem of a rough Y-shaped figure of which the pair of bands along the discocellulars and the anterior portion of the discal two bands may be said to form the... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Singapore | 🇸🇬 Singapore |
With luck
About 10% of wildlife watchers report a Large Fourline Blue sighting in Singapore on a given day, based on 91 verified sightings from GBIF citizen-science data. It is the 251st most-seen of the 1045 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 30%, if each day is a fresh chance.
June–July, October and December–April
In those months about 10% of wildlife watchers report a Large Fourline Blue in Singapore on a given day, against under 5% in May, August–September and November, the lowest months.
Only Singapore, in our data
Singapore is the only city on Wallace's Line with enough records to rate Large Fourline Blue sightings: about 10% of wildlife watchers there report one on a given day.
Same genus: Nacaduba
The closest relatives of the Large Fourline Blue that you can see in Singapore (genus Nacaduba) are Rounded Sixline Blue (about 10%) and Transparent 6-Line Blue (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Large Fourline Blue is recorded against all the insects logged in Singapore (91 verified sightings), 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.
