In a Flash: How You Can Help Fireflies

Growing up in Argentina I remember the summer nights coming home from visiting my grandparents in the country, and looking out into the darkness of the fields, briefly lit up by fireflies. I remember that even though the drive was long (for my child-time perception), I was always looking forward to it and wanted it to never end… Those lights were so magical! How was it even possible that small little insects could create such a whimsical view?

I grew up and moved to other places where fireflies were not present… until I moved to Maryland. My first summer here (and all the following summers, really), I would look forward to those night lights, and then sit outside and just watch them again and again. The excitement I had when traveling back from my grandparents’ is still fresh in me, and I wonder every time at the little insects, no matter how many times I have seen them. In today’s post, I wanted to share some cool resources that will help you find another excuse to continue watching them, learn to recognize the different species and protect them through a variety of ways.

Fireflies from here

North America harbors a very large number of species of fireflies. Among the over 150 species present across the continent, about 15 are known to occur in Maryland (on iNaturalist you can see more details). Although most species prefer relatively humid conditions (e.g., close proximity to creeks or moist areas), they all differ by when they are actively producing light (for example, dusk vs. the night) or their flashing patterns (you can learn a lot more about their biology and behavior from  Mass Audubon).

images of the different fireflies in Maryland
Several species are known to be present in Maryland. Photo:

Love watching fireflies?

Today, the diversity, ranges, and even conservation status of many fireflies in North America are not well understood. This is problematic because studies appear to show that many species may be declining. However, without clear information on where the different species occur and when they are active, it is really hard to know whether species are likely in need of conservation or not. However, given how large the continent is and how fireflies appear to be present in many regions of the country, it is challenging for scientists to get this information efficiently… or is it?

To address this need, some groups of scientists started a set of projects that rely on what we call citizen science. Here, citizens from around the country can voluntarily sign up, go outside in the evening and watch for fireflies, and then submit their observations to the projects. Anybody can participate in these projects, so we can all actually help the scientists help the fireflies, just by taking part in the studies! The projects that are currently happening in our area are slightly different in scope. Let’s see what each one is trying to do.

This project receives both incidental observations (e.g., you were walking and saw a firefly) and information from structured surveys that are geographically restricted to specific targeted areas (one of which includes most of Central and Eastern Maryland). This project is also seeking to gather information in particular about specific species that are suspected to need conservation or need more data in that particular region. Although participation in incidental observations is simpler than in one of the targeted surveys, both are really useful to the scientists. Either way, the project offers a lot of resources to learn how to identify fireflies and will also help you confirm the identifications once they have been submitted. For both participation types, one has to register and create an account, so all submissions can be properly identified and databased. To get to know about this project, and access its resources, visit the Firefly Atlas website.

This project seeks to understand the population trends of fireflies and the potential reasons for those changes. This project is open to anybody who would like to participate and receives observations from any region of North America. Participants engage in performing 10-minute-long surveys once a week during the firefly season. These observations can be done from anywhere (e.g., your backyard, a forest) and even not seeing any fireflies is useful information! To participate, interested people need to create an account, and then become familiar with the number of flash patterns that they may encounter (a neat chart is shared to learn this). Finally, they need to implement a very easy-to-do protocol and submit their results. To earn more about how to participate, check out the Firefly Watch website.

I want to help the fireflies, but I don’t have the time or ability to take on these projects

Although many things are left to understand about firefly biology, scientists already know that some threats exist. If we want to help them, and while we learn more about their ecologies and needs, we can do so by acting to address these threats in our everyday lives.

As for other insects and biodiversity, habitat loss and pesticide use are important threats to their survival. Increasing the diversity of habitats in our green spaces and choosing non-pesticide solutions when possible are great ways to help them! Another threat that is particularly important for fireflies is light pollution. Because fireflies use light to communicate with each other, if we have a lot of lights on during the night, we can prevent them from finding each other, interfering with their reproduction and thus reducing their ability to sustain their populations. Turning off all unessential lights (e.g., accent lights, light strings) present in our green spaces at night can go a long way, while even saving us some money.

By Anahí Espíndola, Assistant Professor, Department of Entomology, University of Maryland, College Park. See more posts by Anahí.

Anahí also writes an Extension Blog in Spanish! Check it out here,, and please share and spread the word to your Spanish-speaking friends and colleagues in Maryland. ¡Bienvenidos a Extensión en Español!

Let’s find skipper butterflies in Maryland using iNaturalist!

A Silver-spotted Skippper on wild bergamont flowers in Maryland, observed recently by iNaturalist user Andy Wilson

I have been writing blog posts for Maryland Grows on a regular basis for a while. To do this, I usually meet with Christa, the blog manager, every 6 months and plan on the topics I will cover over the next few months. When we do this, we seek to cover the needs we see from readers, but sometimes the topics come to us as a result of our discussions. This is exactly what happened for today’s topic. Today, let me tell you the story of how this came to be, and at the same time show you a great free tool available at our (literal) fingertips!

The story

Picture myself and Christa on Zoom, planning dates and topics for the next few months. It is February and it is cold outside. We have been making our way through the upcoming months, thinking of what each one will look and feel like, and what will be growing and buzzing around in each of them. August comes. How is August in Maryland? What do we usually see around? What issues are common in green spaces in August?

I think of August and in my very pollination-biologist-biased way start thinking of the pollinators we see in August… And what comes to me is “butterflies!” I remember writing about butterflies in the past, so maybe butterflies are a bit redundant as a blog topic. However, I don’t remember writing about a specific group of butterflies called “skippers,” which are common in Maryland. So, sure, let’s write about skippers, but what skippers are around in August? As we discuss and try to narrow down the topic, I open this incredible tool I use very regularly to learn about local species, report observations I make, and do research in my lab. This magical incredible tool is called iNaturalist.

So, there I am, opening iNaturalist’s website, and doing a quick search to find out the most common and most abundant skippers we find in Maryland in August. I am doing this, and Christa is intrigued; what am I doing? How am I figuring this out? I decide to share my screen to show her what I’m doing. Christa is amazed. You can do all that with iNaturalist?! The world needs to know! So, there we have it. Our blog topic showed itself to us. Today’s blog will be about what iNaturalist is, how to use it, and what type of information we can share with and learn from it. I hope that this blog will motivate you to start using it as well, and, like me, every time learn something new about species here and elsewhere in the world.

iNaturalist; ever heard of it?

We live in the times of social networks, like Twitter, Instagram, and Facebook… And as it turns out, social networks are really useful to science too! iNaturalist is one of those networks!

iNaturalist is a global social network that allows people to submit, find, and explore biodiversity observations from around the world. What does this mean? This means that through this network, every time a person observes an organism anywhere in the world, they can take a picture of it, upload it to iNaturalist, and then have the network help them identify what it is through its picture (using image recognition software), its location, its date, and the input of other members. This information is then stored in a public database, which can then be explored easily by anybody, including scientists, you, me, kids, conservation agencies, and more! At the end of the day and using all these data, the network can output maps and other information of any species ever added, allowing for the reported localities to be found, and, if the user wants to, visited to try to see the organism in question. Today, iNaturalist has over 5 million users worldwide, with over 109 billion observations of over 380,000 species!

OK. But how does iNaturalist work?

To explain this, let’s come back to my skippers story. I am talking to Christa and want to know what the most abundant skipper in Maryland may be, and whether it is present in August. To do this, I first go to the iNaturalist website (if on a computer; otherwise, I would open the app on my phone). This is what the page looks like.

Screen shot of the iNaturalist home page
Continue reading