31 July 2021

Butterfly of the Month - July 2021

Butterfly of the Month - July 2021
The Common Sailor (Neptis hylas papaja)

A Common Sailor feeding on the ripened fruit of the Singapore Rhododendron (Melastoma malabathricum)

We are well into the 2nd half of 2021, as the world is beginning to reach a limit with pandemic fatigue. Some governments are beginning to consider treating the virus as "endemic" and living with it will be what we may have to contend with, in the near future. After all, how many more lockdowns, quarantines and movement restrictions can the populace take?

A Common Sailor perched with its wings opened flat to sunbathe.  Note the metallic green sheen on its thorax when viewed from above.

As vaccination programmes reach a certain critical number, some jurisdictions are planning to relax various restrictive measures. For example, face-masks may be dispensed with, or movement controls and safe distancing relaxed when a benchmark percentage of the population has been fully vaccinated. The many restrictions, safety measures and movement controls have already taken their toll on many economies all around the world , with some companies facing imminent and permanent closure.

Over in Tokyo, the Japanese government appeared to have taken the COVID19 bull by the horns and decided to proceed with the "2020" Tokyo Olympics in 2021. Perhaps the motivation behind the decision to proceed to hold the Olympic games could be economic rather than prudence. But here it is, the Games have begun, but with most spectators watching online and stadiums and games venues largely empty. However that does not take away the glory from the athletes who achieve the podium positions in their respective sports.

Back home in Singapore, the resurgence of the Delta variant in KTV lounges sparked off another round of restrictions in the community. This was followed by several other clusters emerging from a wholesale centre, which then moved to public wet markets. In just a few days, the numbers of new infections hit three-digits and disrupted the progress of opening up. Dining out in public places is no longer allowed until mid-August as the government rushes to vaccinate the population.

A classic pose of the Common Sailor perched on a blade of lallang

Already the Singapore government is debating on the possibility of "opening" up and living with the virus as if it were just the common influenza. Data collected and findings that show that fully vaccinated infected individuals have mild symptoms or even asymptomatic, has given optimism that it may one day be possible to take COVID19 in our stride as an endemic disease that is no longer life-threatening. We look forward to that day!

Our feature butterfly for July 2021 is the Common Sailor (Neptis hylas papaja). This butterfly is one of the four Sailor species found in Singapore - three from the genus Neptis, and one from Phaedyma. The Common Sailor is one of the black-and-white lookalikes and sometimes confused with the Burmese Sailor or Short Banded Sailor. However, when the butterfly is at rest, there are distinguishing characteristics in the markings that will separate the lookalikes.

The Common Sailor has a distinctive weak flap-glide-flap flight that separates it from the related but similar looking Sergeants (Athyma spp) that have a more powerful and robust flight. The Common Sailor is widely distributed in Singapore, being found in urban parks and gardens as well as the forested nature reserves and our offshore islands.

The species has a black and white striped upperside. The forewing white cell streak is usually interrupted by a thin black line towards the cell end. The underside of both wings is a rich golden brown. The white stripes are distinctly outlined in black and this is one of the distinguishing attributes of this species to separate this species from its lookalike cousins.

A mating pair of Common Sailors

The eyes of the Common Sailor are transparent and the compound eyes are bluish grey.  On the upperside of the thorax, there is an iridescent greenish-blue sheen. Its abdomen is not white-ringed next to the white discal band on the hindwing.  Its antennae clubs are usually orange-yellow tipped.

A Common Sailor feeding on the ripened fruit of the Singapore Rhododendron (Melastoma malabathricum)

The caterpillars of the Common Sailor feed on a variety of host plants, all from the Fabaceae family. The local host plants on which the species has been successfully bred are : Calopogonium mucunoides, Canavalia cathartica, Aeschynomene americana, Senna alata, Psophocarpus tetragonolobus and Centrosema molle.

Text by Khew SK : Photos by Khew SK, Loh MY, Tan BJ and Anthony Wong