National Moth Week is an annual event which is live through the last week of July. A time when 'moth-ers' of all ages and abilities are encouraged to learn about, observe and record moths wherever they are in the world. It is an event that has grown in popularity in India over the last few years as more and more people jump on the moth watching bandwagon. India is now only second to the U.S. in the number of National Moth Week events registered each year. 

Pritha Dey is the country coordinator for National Moth Week in India. A moth biologist obsessed with the diversity, distribution and evolutionary ecology of moths in India, she is a post-doctoral fellow at the Centre for Ecological Sciences, Indian Institute of Science, Bangalore. Dey is also a team member and reviewer for the Moths of India website, a citizen-science based data depository on moths in India.

We talk to Pritha Dey on the occassion of National Moth Week to learn about this extraordinary group of insects, how moths are different from butterflies, the basics of moth watching and more.

Here is an edited transcript of the conversation.

     Field photo   | Nature Infocus
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Pritha Dey documents moths in Agumbe, Karnataka, using a light-trap. Photograph: Labonie Roy

Before we talk about moths, could you tell us how you came to choose such an unusual career in science?

When I joined the Wildlife Institute of India (WII) in 2013, just after my master's, I was part of a project where I had to document moths and moth assemblages in different elevations in the Western Himalayas. I had done a project on butterflies during my bachelor's, but I had never worked on moths before. I learned a lot during that period. Because I had to sample in remote areas, I used to stay in high-altitude villages where people would ask me what I was doing in the forest at night, and I had to explain to them what moths are and what I was trying to do with my studies. 'Ohh raat ki titli hai,’ they would say, referring to moths as butterflies of the night. They did not relate to moths as much as they did with butterflies, and that stuck with me. I kept reading more about them and found out that there is not much information about moths or their ecology. So that gave me the impetus to go forward with studying moths. As you said, it was not conventional in an institute like WII, where, at the time, most people were studying large mammals. But I found an empty niche where I could work on an interesting yet understudied group of insects.

     Moth image Erebus ephesperis by Pritha Dey | Nature Infocus
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"Butterflies are nothing but day-flying moths. They have evolved from moths, a natural selection prompted by nectar, which is more readily available during the daytime when flowers are open." Owl moth (Erebus ephesperis) | Photograph: Pritha Dey

How are moths different from butterflies? What is your favourite moth species from India?

Butterflies are nothing but day-flying moths. They have evolved from moths, a natural selection prompted by nectar, which is more readily available during the daytime when flowers are open. In fact, the planet's moth diversity is around ten times its butterfly diversity. The main difference is that while most moths are nocturnal, butterflies are diurnal. While moths have variable antennae, butterflies have antennae with a club-shaped structure at the end. Also, when the butterflies are at rest, they keep their wings folded, whereas moths rest with their wings unfolded.

There are exceptions, like butterfly-moths of the family Callidulidae, which have characteristics of both butterflies and moths. There are also certain groups of day-flying moths, like the Zygaenidae family. Tiger moths, the Arctiinae group of moths, are also day-flying and use their bright colours as a defence against visual predators.

There are many favourites! One of my favourite moths is the Harlequin moth, a beautiful day-flying moth, very vibrantly coloured. I also have a soft spot for emerald moths, green in colour as their name suggests. Recently, I've been working on larger moths like hawk moths, which is another group of moths I am very fond of.

     Campylotes histrionicus Eaglenest WLS Tarun Karmakar | Nature Infocus
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"Moths are important nocturnal pollinators. They are food for bats and other nocturnal birds and are a crucial part of the food chain." Harlequin moth (Campylotes histrionicus) | Photograph: Tarun Karmakar

Moths are everywhere around us, but no one seems to care. It must be frustrating for a moth scientist. How do you explain our relationship with moths?

Frustrating as well as motivating! I know butterflies are more visible. They are colourful and visit flowers all the time. Moths, just because they are nocturnal, are less visible. One of the main aims of my work is to tell people that there is more to moths than what meets the eye. They are as pretty as a butterfly or any other insect. I mean, have you seen a Harlequin moth?

Because of their nocturnal nature, moths are seen as symbols of darkness, as bad omens. If you see movies like Silence of the Lambs, on the poster, there is a moth on the face of Jodie Foster, associated with a serial killer. Then there are urban legends like the moth man, a mystical creature that goes around killing people. Culturally, moths have been represented poorly, and this has affected how people perceive moths.

People also have this notion that moths might not be good for their health or that they could be allergic. Some moth species are known pests, like the Indian Meal moth, seen in our kitchens where food is stored, as they complete their life cycle by infesting rice boxes or pulses. Sometimes, we only know them from the lens of a pest species, but that is just a fraction of the entire diversity. Moths are important nocturnal pollinators. They are food for bats and other nocturnal birds and are a crucial part of the food chain.

     Moth image Ambulyx sp by Pritha Dey | Nature Infocus
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"First of all, I would say that moth watching is interesting because you don't need fancy equipment, all you need to do is to turn on the light around your house and see what species show up." Ambulyx sp. | Photograph: Pritha Dey

You are a team member and reviewer of the Moths of India website. How valuable is such a resource for enthusiasts to get into moth watching and what advice do you have for beginners?

I think it is an easy-access resource for people to be aware of a beautiful group of insects. It is not only moth experts that are part of the website; they are present only to review observations and to check whether you have identified the moths correctly or not. Moths of India is a citizen science portal where anyone can contribute their moth observations. It is a fantastic way to generate data and to make people appreciate the diversity around them. To identify a moth species from your backyard, all you got to do is log in to the website and use the location filter to find out. We are trying to build a repository with as many species as we can record. There are an estimated 12,000 species in India.

First of all, I would say that moth watching is interesting because you don't need fancy equipment, all you need to do is to turn on the light around your house and see what species show up. Photograph them and use the website or other online resources to get them identified. And once you get into the habit of moth watching, you can try exploring other areas. Maybe you are going camping; just put out a light and a white sheet and see what moths make an appearance. Just like you do for birdwatching, how you carry your binoculars everywhere, bring a light source with you. It is not rocket science, and anybody can do it, 6-60-year-olds. It is easy and cost-effective.

Monsoons are a better time for moth watching because a lot of the moths are breeding at this time of the year. You will find a lot of caterpillars around. But different species emerge at different times of the year. The technique of light-trapping works well around the new moon.

     Moth image Eumelea sp by Pritha Dey | Nature Infocus
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"Record your observations and upload them on a citizen science portal so that it is also visible to others." Eumelea sp. | Photograph: Pritha Dey

National Moth Week kicks off in the last week of July. As the country coordinator for India, what would you like to tell our readers about the annual event?

National Moth Week is a global citizen science programme which has been in place for the last ten years, and only in the past 3-4 years has it been a popular event in India. It is gaining momentum, and people are slowly taking an interest. It's not that you have to do moth watching only this time of the year. Since the entire world is doing it, it is an opportunity to get registered on the website (you can register as an individual, a group or a school). You can watch moths wherever you are. You don't need fancy equipment or the right skills even. Just turn on the lights and see what is around you. Record your observations and upload them on a citizen science portal so that it is also visible to others. It's just one week, have fun moth watching!