30 August 2023

Butterfly of the Month - August 2023

Butterfly of the Month - August 2023
The Large Fourline Blue (Nacaduba pactolus odon)

A Large Fourline Blue feeding on the flowers of the Mile-A-Minute climber

Two thirds of the year 2023 have come and almost gone, as we wind down to the last 48 hours of the month of August. Singapore has celebrated its 58th birthday, as the nation reminisces where it came from, and look ahead to where it will be in the coming decade and beyond. The month of August belongs to the astrological sign Leo. For those born between 23 July and 22 August, your zodiac sign is Leo. We featured Capricorn, Aquarius, Pisces, Aries, Taurus, Gemini and Cancer in the preceding Butterfly of the Month blogposts and will now move into the next in the series. The 12 zodiac signs are Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces.


Leo (♌︎) (Ancient Greek: Λέων, romanized: Léōn, Latin for "lion") is the fifth sign of the zodiac. Leo is associated with the mythological Nemean lion. The lion is a very important and prominent symbol in Greek mythology. In Greek mythology, Leo was identified as the Nemean Lion which was killed by Hercules during the first of his twelve labours. Hercules killed the Nemean Lion with his bare hands, as the lion was impervious to all weapons. This zodiac sign is often represented by fire.


Leos tend to be full of primal, creative energy. This is a sign that embodies the fire that lives within us all. Those born under the sign of Leo wants to see and be seen, just like the sun that rules it, which is why Leo is associated with visibility, attention, courage, generosity, and creative impulses. Leo's symbol, the lion, is equally telling: Lions are the kings of the jungle, known for their fierce courage and natural regality.


Leos often see themselves as born leaders and are never ready to sacrifice this power. They will try to take leadership positions in every situation no matter whether it is teamwork or family. Moreover, they can be very opinionated and find it hard to accept another person’s viewpoint. They are determined by nature, and focused on completing whatever task they start. Leo is a good friend who will protect people he loves and supports them in any life situation. Their attitude to friends is exceptional and they do not pull punches and can be very honest and direct.


One of the negative traits of Leos is arrogance. They often cross the line of simple confidence that gradually transforms into conceit and arrogance. Their belligerence and self-centredness in their pursuit of dominance and a centre of attraction does not earn them respect or win them popularity votes in certain situations. However, they will not bow down to threats and will spoil for a fight to defend their throne. 

A mating pair of the Large Fourline Blue spotted at Lornie Park Connector

Our Butterfly of the Month for August 2023 is the Large Fourline Blue (Nacaduba pactolus odon). This species was re-discovered in late 2009 and reinstated to the Singapore Checklist. One of the many lookalikes in the genus Nacaduba, the Large Fourline Blue is one of several species in the pavana group which lacks the pair of sub-basal lines on the underside of the forewing, hence having only "four" lines on the forewing.


The Large Fourline Blue is moderately rare in Singapore, but is widely distributed across the island from forest habitats to urban parks and gardens. It is the largest species of the genus and displays the typical behaviour of basking in the late afternoon sun with opened wings. At other times of the day, The Large Fourline Blue may be seen settled in the shade.


The male of the Large Fourline Blue is purplish-blue above, with marginal borders of about 1mm thick. The female is pale blue with the distal portions of the wings almost whitish, and with broad black marginal borders of about 3-4mm thick on both wings. On the underside, the striations are usually thick and more diffuse than most species in the Nacaduba genus. The hindwing features a filamentous white-tipped tail at vein 2.

A Large Fourline Blue puddling at a sandy streambank

The species can also be encountered feeding on flowering plants and bushes like the Snakeweed, Stringbush, Mile-a-Minute and others. They are quite often seen puddling at damp muddy footpaths that are tainted with organic matter. When disturbed, the Large Fourline Blue flies erratically and can be skittish. The species has been successfully bred on Entada spiralis in Singapore.

Text by Khew SK : Photos by David Chan, Federick Ho, Khew SK, Loh MY, Low JK, Aaron Soh and Horace Tan