08 March 2020

Butterfly of the Month - March 2020

Butterfly of the Month - March 2020
The Lesser Grass Blue (Zizina otis lampa)

A Lesser Grass Blue perches on a dried flower head

It is the month of March 2020 already, and the world seems like a changed place, with many countries reeling from the pandemic situation caused by the coronavirus, now designated COVID-19 by the World Health Organisation. Originating from Wuhan in China, the spread of the virus has created concern all around the world.

Initially thought to be limited to China and a few Asian countries, the infection rate has been climbing around the world. Countries that earlier had not taken definitive action to manage the spread appear to be now paying the price of increasing numbers of infections. In the initial weeks of the virus spread, Singapore was considered to have the next highest number of infections after China. The government kicked in an entire pandemic management system of testing, tracing and mitigating spread, whilst closing our borders to travellers from countries with high infection rates.

Today, around the time that Singapore raised its DORSCON alert to orange a month ago, the number of infections has risen to 150. However, at the global level, Singapore now has dropped to the 16th highest number of infections, with countries like South Korea and Italy hitting numbers like 7313 and 6092! Whether or not Singapore's pandemic management system works, we cannot be certain as our little island is geographically small, yet the population density per unit area is extremely high. But the numbers surely tell a story and we will have to wait and see.

But the lessons that the COVID-19 pandemic brought across the globe, is something that we should be reflecting upon. One was the frenzied buying of face masks, hand sanitizers and thermometers during the initial days. It was amazing how fast these items went out of stock, and how the people who needed these things most, were deprived of them.  Many were willing to spend hours queuing up whenever a shop had these items for sale. On the business side, unscrupulous people were also quick to profiteer from the surge in demand, and suddenly the ubiquitous face mask became a rare item, and traded on the black market!

And then when the alert was raised to orange in Singapore, the shelves at the local supermarkets and provision shops were emptied in the flash of an eye. Essential items like rice, noodles and other food items disappeared in a matter of minutes as large crowds hit the shops. Interestingly, toilet paper was also in high demand. The world watched in amusement at the seemingly illogical behaviour of how some Singaporeans reacted. And cyber-watchers and trolls poked fun at us.

A female Lesser Grass Blue showing its upperside

Fast forward to a month later, when the infection numbers rose across the world, similar behaviour was seen across different countries. So it appears that it is a basic human self-preservation instinct that was never nationality-centric in the first place. Video clips of rather violent supermarket altercations appeared on social media (over something as "insignificant" as toilet rolls). Such events also happened in many other countries where panic drove this anti-social behaviour.

A Lesser Grass Blue feeding on the flowers of the Common Vernonia, a wildflower

But amidst the pandemonium across the world, let us take a step into our calm world of butterflies and take a look at a small and humble species that is common in our urban environment - the Lesser Grass Blue (Zizina otis lampa). One of the region's smallest butterfly species, the Lesser Grass Blue is common, and sometimes abundant, in open grasslands and flowering bushes in urban parks and gardens.

A Lesser Grass Blue feeding on the flower of a Spanish Needle

The male Lesser Grass Blue is purple-blue above, with broad black borders. The female is predominantly blackish brown above except at the wing bases, and usually unmarked. The underside is pale grey with small dark spots on the fore and hindwings. The diagnostic spot in space 6 of the hindwing below is moved out of line with the adjacent spots. Typical adults' wingspans range from 20-25 mm.

A female Lesser Grass Blue puddling on a rock

The species can regularly be found feeding on small wildflowers in urban areas and often, several individuals can be seen together, fluttering restlessly amongst grassy areas. An observer likened them to small "pesky mosquitoes" buzzing around the grasslands, rarely stopping long enough for a close look.

The Lesser Grass Blue is usually active on hot sunny days, but in the evenings, they can be found resting on grass flowers in the cooler temperatures and on blades of grass, settling down for the night. They also have a habit of rubbing their hindwings up and down when at rest, like many Lycaenidae species.

Various stages of the Lesser Grass Blue's life history, bred on Desmodium

Their caterpillar host plants are Desmodium and Mimosa pudica, but there are likely to be other urban plants that they can feed on.  As both their preferred host plants are weeds, they are often vulnerable to the grass cutters' blades and area fumigation to eradicate the dreaded Aedes mosquitoes.  But yet, the Lesser Grass Blue is in no danger of becoming endangered just yet.

Text by Khew SK : Photos by Alan Ang, Chng CK, David Chan, Les Day, Foo JL, Federick Ho, Goh EC, Khew SK, Koh CH, Loh MY, Loke PF, Mark Wong and Benjamin Yam.