The four species of newly-discovered tiger moths. Left to right: First row: O. suryamal rekhae, O. suryamal. Second row: O. zedesi and O. ghatmatha [Image credits: Aparna Kalawate]
Thus hath the candle sing'd the moth.
O, these deliberate fools! When they do choose,
They have the wisdom by their wit to lose.
Thus wrote William Shakespeare in his famous play The Merchant of Venice, seemingly mocking how moths are foolish creatures that die falling into the candle flames. Active during the nights, these butterfly-like insects get attracted to any source of light. With around 160,000 known species so far, moths bemuse us with their diversity on the planet. In a recent endeavor, scientists from the Zoological Survey of India (ZSI), Western Regional Centre, Pune, Maharashtra have discovered three new species and one subspecies of moths from the Western Ghats.
Moths are closely related to butterflies but are nocturnal with unique scales on their wings and have differences in their antennae.
“But butterflies have received more attention than moths from naturalists, perhaps because they are nocturnal,” points out Aparna Sureshchandra Kalawate, the lead author of the study.
Tiger moths are a group of moths belonging to the family Erebidae and subfamily Arctiinae with around 11,000 species. As the name suggests, they have tiger-like brightly coloured stripes on darkly-coloured wings. In the current study, published in the Journal of Insect Biodiversity, Aparna and her colleagues have discovered three new species and one subspecies of tiger moths.
The three new species, Olepa ghatmatha, Olepa suryamal, Olepa zedesi, and the subspecies Olepa suryamal rekhae belong to the genus named Olepa and have some interesting stories behind their names. O. ghatmatha and O. suryamal are named after the locations in which they were found. O. zedesi is named after ZSI – the type locality and the institution that made this discovery and the subspecies O. suryamal rekhae is named after Aparna’s mother, Rekha Sureshchandra Kalawate, as an honour for her constant encouragement and support to Aparna’s work.
Species of genus Olepa are distributed across South and South-East Asia, with most of them found in India and Sri Lanka. However, in an earlier study, the researchers had spotted a species of tiger moths, Olepa schleini, (originally described from Israel), in the Western Ghats region of Maharashtra. “One more moth sample matching with Olepa schleini with a shallow genetic difference, described as a subspecies of Olepa schleini namely Olepa schleini chandrai,” says Dr. Aparna.
This accidental discovery stressed the need for a systematic study of the species in the genus Olepa, which despite being found in India, are poorly studied.
“Our discovery created an interest to study this group and to dig the hidden biodiversity treasure lying in our forest,” says Dr. Aparna about the motivation behind their current study. The result was the discovery of the three new species and a subspecies.
For years, before DNA analysis became ubiquitous, taxonomists relied on the morphological and genitalial characters of the moths and their wing patterns to identify moths. In their study, Aparna and her colleagues chose DNA barcoding, “DNA barcoding works on the key principle that genetic variations between species are higher than those within a species,” explains Dr. Dinesh, who is a coauthor of the study. “When we study multiple samples of similar-looking moths, DNA barcodes show the similarity or the variations in their DNA, which can help us identify them as the same or different species” says Shabnam - another coauthor of the study and a member of the team.
The researchers used an integrated approach involving morphological, genitalial characters and DNA barcoding for the establishment of the new species. The researchers hope that such an integrative approach may uncover many such hidden species in the future from India.
“There could be many more species out there waiting for their formal naming ceremony,” quips Dr. Aparna. “We would need a thorough sampling for that to happen.”
With discoveries of insects, amphibians and reptiles in the country’s biodiversity hotspots, this is an exciting time for naturalists. However, increased threats to these creatures mean that we may lose some before getting to know them. “As of now, we do not know what could be the specific threats for tiger moths. However, like most species, they may be affected by habitat change due to the changing climate, deforestation and urbanisation,” says Aparna. Conservation of the not-so-popular but important moths should be critical.
“We need to learn, observe and conserve moths, which are an essential part of our ecosystem and help us in maintaining the balance of nature,” she signs off.