SINGAPORE - Have you seen those greyish-brown palm-sized creatures of flight in your neighbourhood recently? These moths have not been so visible in nearly a decade. But fret not, say experts.
The Tropical Swallowtail Moths, otherwise known as the Lyssa zampa, are "in season" now and a "population outbreak" is the reason for their recent abundance, said butterfly expert Khew Sin Khoon, who is also an honorary research affiliate at the Lee Kong Chian Natural History Museum at the National University of Singapore (NUS).
"These moths are totally harmless. If you touch them you'll probably hurt them more than they'll hurt you," said Mr Khew.
Experts say that the numerous documentation of sightings this time round and heavy flowering due to rainfall could be reasons for the bumper crop of moths this year.
"Many flowers serve as a nectar source and it is well known that higher nectar abundance increases butterfly and moth populations," said NUS ecologist Anuj Jain, who also heads the butterfly interest group at Nature Society of Singapore.
While the emergence of the moths happens throughout the year, it peaks from May to July, with early signs in April. N. Sivasothi, a lecturer at the Department of Biological Sciences at NUS, said that the sightings this time are believed to be the largest since 2005.
So far, he has received more than 700 records of the sightings from netizens who spotted them all over Singapore.
The moths, found also in neighbouring countries like Indonesia and Malaysia, are believed to have emerged from forested areas "where the caterpillars would have eaten leaves of plants and eventually pupated", said Mr Sivasothi, a research associate at Lee Kong Chian Natural History Museum.
"When they emerge as moths, they would fly away in search of mates and suitable egg-laying sites. Many reach urban areas, attracted by the lights."
Over the last few weeks, netizens have been posting sightings of the insect on social media sites Facebook and Twitter. The insects have been spotted all over the island, from office windows in Collyer Quay to void decks in Bukit Batok Central and even MRT stations.
Teacher Samuel Liu had a few encounters with these flighty creatures on Tuesday. He saw them in his home in Tanah Merah and at a nearby shopping mall.
"These moths are not rare but it's still a nice sight," said the 26-year-old. "We hardly get to see something like this in urban Singapore."