A larva with light: Can you guess what insect this is?

The end of June brought a very exciting event. As I was cutting holes in the landscape fabric to plant some late-season flowers in my high tunnel, I found several larvae of a great beneficial insect! I guess it was the perfect environment, as I found at least 10 that evening. It was moist, although in the photo it looks pretty wet because I was running my drip irrigation water. When I found it, I was so ecstatic that my 5 year old daughter thought something bad had happened with all my yelling! I then shared a photo with my whole family. Needless to say, no one else seems to get quite as excited as I do about good bugs. Below are some photos from that special evening. Do you know what it is? Have you ever seen one? I’ll give you a few clues so you can see if you know what it is.

  1.  As larvae, they are incredible predators of many ground dwelling garden pests, like snails and slugs! 
  2. The adult form is a beetle so they have a complete life cycle —  egg, larvae, pupa, and adult!  
  3. Size: approximately ¾’’. 
  4. The larvae and adults have bioluminescence, an amazing ability to “light up”.  

That’s right, the last clue should have given it away. This is a larva of a lightning bug.

Did you know lightning bugs, also called fireflies, are actually beetles? They bring joy to everyone with their beautiful displays of flashing lights. Lots of additional information about them can be found here: https://www.xerces-dev.org/endangered-species/fireflies/about

Adult beetle. Photinus pyralis, known by the common names common eastern firefly and big dipper firefly

So where could you find these awesome critters in your landscape? Most species have at least a 2-year life cycle, and 95% of their life is in larvae form. Most adults only live 2-4 weeks. They like moist, dark areas near the soil surface, since that will be where they find their next meal.  Sometimes they even hide in the crookes and crevices of tree bark. 

Below are some actions you can take to create a habitat to attract fireflies. This information is provided by Firefly.org.

  1. Eliminate light pollution in your landscape (turn off unneeded outdoor lights, keep your curtains drawn). Fireflies use their flashing patterns to attract mates. Extra lights can disrupt their ability to find each other. 
  2. These critters thrive in wet areas around ponds, streams, wetlands, and swampy areas.  Add a water feature to your landscape if you do not have natural sources. 
  3. Avoid pesticides, especially broad-spectrum insecticides which kill many types of insects indiscriminately (even the beneficial ones). 
  4. Do not over-mow your lawn (taller grass gives fireflies a place to hide during the day). 
  5. Dead logs and leaf litter provide great habitat, so try to create an area in your landscape that has a  natural area with these materials. 
  6. Plant native trees and native grasses to provide shaded habitat. Shade helps conserve soil moisture which attracts food sources for firefly larvae.  

My family is lucky to live in a rural area near a small stream and swampy area, so we are blessed to see a wonderful display of fireflies for several months each year. Check out my blog from last summer:  Firefly or Lightning Bug: You Decide!  

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland, edited by Christa Carignan, Coordinator, Home & Garden Information Center, University of Maryland Extension. See more posts by Ashley and Christa.

In praise of good bugs. Good bugs are a gardener’s best friend.

Boonsboro, MD – 

Ground beetles.

What do all these insects have in common?  They are the good guys, the beneficial insects that help keep bad bugs at bay in our gardens. 

Nine out of 10 insects are beneficial. Yes, most of those flying, crawling, buzzing and burrowing bugs out there are actually helping you battle the few nasty bugs that harm plants. 

How? Some are predators that eat bad bugs.  Others are parasites that lay eggs on bad bugs so their babies get fed. 

So instead of reaching for that spray bottle when you see a bug ambling across your petunias, pause.  Is it harming the plant?  Or is a good guy just moseying by? 

Think before you squish or spray.  When you take out good bugs, you’re taking out your allies. 

Instead, send me a photo or bring me a sample so I can identify the insect and suggest controls if needed.  Let’s work together to keep – and build – your army of helpful insects. 

To know beneficial insects is to love them.  So let’s meet a few.  

Spiky ladybug larva
Alligator-like ladybug larvae eat thousands of aphids and other bad bugs. Photo credit: Whitney Cranshaw, Bugwood

The ladybug is the good bug poster child.  It happily dines on thousands of aphids in its lifetime as well as scale, spider mites, whiteflies and more. 

Lacewing larva
The larvae of delicate adult lacewings eat aphids, lace bugs, caterpillars, beetle larvae, mites and more. Photo credit: Whitney Cranshaw, Bugwood

Lacewings are beautiful lacy-winged (hence the name) insects.  They may look delicate, but are voracious hunters that eat many different dastardly bugs. 

Some wasps are parasitic, laying their eggs on harmful insects.  There is even one called the scoliid wasp that lays its eggs on Japanese beetle grubs in the soil. 

Other generalist predators like praying mantids and assassin bugs stalk and eat a wide variety of insects – good and bad – to keep their populations balanced.  

I’m betting that now that you’ve met a few beneficial insects, you’d like to know how to attract more to your yard.   Here are a few tips. 

First, give them the basics: food, water and shelter. 

Many insects need pollen and nectar.  So make sure something is blooming from spring through frost to provide both food and shelter.  Native plants support native insects best.

Many beneficial insects are small, risking life and limb to sip water from a traditional birdbath.  So put water in shallow containers. A pot saucer will do. 

Some plants are better at attracting beneficial insects than others. Herbs with their tiny flowers are sized just right for pint-sized beneficials.  

Daisy-shaped flowers such as coneflowers and zinnias are magnets for good bugs as are plants with umbrella-shaped flower clusters such as yarrow and dill. 

One of the best things you can do for beneficial insects is to stop or limit your use of chemical insecticides. Chemicals don’t discriminate, killing both good and bad bugs.  

This doesn’t mean you can’t control garden pests.  I’m just suggesting a kinder gentler approach.  

Insecticidal soap, horticultural oil and Bt – the holy trinity of organic controls – manage most bad bugs.  Add cultural practices such as handpicking, row covers and crop rotation and you have an arsenal of crackerjack controls. 

Don’t let bugs bug you.  Most are friends.  Embrace them.  Encourage them.  And deal swiftly with the few bad bugs with organic controls.  They work. 

Annette Cormany, horticulture educator, University of Maryland Extension – Washington County

This year, host bees in your garden

The sun and the warm(er) days are back! Oh gosh, it felt like forever! And now, of course, I am feeling like I have to get out there and start doing stuff outdoors! And because I love the little creatures, one of the things I want to do is make sure that this year my garden becomes a pollinator’s paradise. If you are in the same boat as me, come along and let’s talk about how to make our gardens inviting to pollinators!

Like us, pollinators need food and a place to live

We hear a lot about pollinators and the plants we can grow to help them. And it is true, to live and thrive pollinators need food, and that food usually comes from plants. Indeed, to sustain pollinators, it is key that we provide food for them. However, we often forget that they need something else to thrive: a place to live! And because there are SO MANY types of pollinators, let’s for this one time focus on only one group, the bees!

Even though many people think only of honeybees when we talk about bees, most bees do not live in colonies like honeybees do, and are in fact solitary. Solitary bees are indeed the vast majority of bees. In Maryland we have about 400 different species of them, going from tiny to very large. Check out this awesome free book about bees from our region.

Unlike honeybees, each of these wild bee species has different nesting requirements, and many of them will nest readily close to our houses if they find the right conditions. Here I will give you some pointers on how to create those conditions to not only attract bees with flowers, but also help them live close to your garden.

How do wild bees live?

Unlike honeybees which lay eggs throughout the growing season, wild bees usually lay eggs only at certain times of the year, meaning that their life cycle is different from that of honeybees. Most solitary bees in fact lay eggs at only one point throughout the growing season (for example, only in the spring, summer, or fall).

orchard bee nest
Wild bees lay eggs in their nests and leave food to them. When the larvae hatch they find the food and can finish their development in the absence of the mother. Photo: USDA ARS.

Whenever they are ready to lay eggs, bee mothers start looking for a place to nest, and it is only during this time that they will be building their nests. Once the eggs are laid, the mother leaves and those eggs stay in the nest along with some food (usually pollen mixed with some nectar). After hatching, the larvae eat the food the mother left for them, and they continue feeding and growing until they are ready to leave the nest as adults, usually the following year. This means that for most bees there is no or very little maternal care of the offspring, and most of the time spent in a bee’s life is as a larva, growing and getting ready for the “outside” world.

Where do wild bees live and how can I help them nest?

Wild bees have a variety of nesting preferences. While some nest in the ground, others dig holes in wood, use already-existing cavities, or parasitize other bees’ nests by consuming the reserves of their hosts (yeah, bees can be sneaky like that!). Understanding this is important, because depending on the resources we provide for nesting, different species will be attracted to our gardens.

Keep some ground undisturbed – Ground-nesting bees

green sweat bees
The green sweat bees are very common in Maryland and can be seen often digging on bare ground and visiting flowers. Photos: J. Gallagher; Ilexin.

If you would like to support these bees in your garden, you can make sure to leave some of your garden soil undisturbed or bare. If you do this, you will realize that many bees will be attracted to that section, and if you pay attention, you will realize that many are actually coming in and out of the ground! These are your ground-nesting bees! In Maryland, some ground-nesting bees that you may have seen visiting flowers are the small and shiny green sweat bees.

Leave some wood in your yard – Carpenter bees

carpenter bee
The large carpenter bees nest in shallow galleries they excavate in soft wood. Photo: Missouri Department of Conservation.

In our region, these bees are represented by the very large shiny carpenter bees of the genus Xylocopa. These bees have strong mandibles they use to excavate soft wood in order to build their nests inside. If you would like to attract these bees to your garden, make sure to leave relatively large branches and logs available for them to nest in. For this, you can turn a corner of your yard a bit wilder, and at the same time, leave branches there to allow other beneficial organisms to establish in your garden.

Bee hotels! – Cavity-nesting bees

bee hotel
Cavity-nesting bees are attracted to bee hotels. Here we have a particularly elaborate bee hotel; you can go simpler at first and then evolve into this if you’re just starting. Photos: M. Lankford; Piqsels.

Unlike carpenter or ground-nesting bees, these bees do not create the cavities, but rather use those that already exist. This is the group of bees that is attracted to those cute bee hotels one can build or buy. A natural option for supporting these bees is also by not cutting down to the ground the hollow stems of some plants at the end of the season. Many bees nest within these stems, and will die if they are chopped-off during the winter. Species in this group of bees nest in the spring, summer, or fall. For this reason, if one wanted to use bee hotels to attract these bees, one should establish them early in the spring.

There are a multitude of types of bee hotels, with some involving little tubes that can be removed, holes drilled into wood, a collection of small hollow twigs and branches, paper rolls, etc. Check out this site to see many options. Independently of the type of bee hotel you want to use, something important is to make sure that you keep the cavities clean for the bees to develop in healthy conditions. Failing to do so may actually harm the bees we are trying to support, because they may continue to be attracted to the nesting site we are providing but may eventually become sick and die because the place was unhealthy.

Now it’s our turn!

I really love watching bees build their nests, independently of what they look like. Maybe I’m just nosy, or maybe this is really why I’m a biologist, but that peek into these little animals’ lives makes me feel connected to them and keeps me in awe at how wonderfully diverse and fascinating life can be. When you are planning your garden this year, I invite you to consider the flowers for your bees, but also count in where you plan to have them live! And then, later in the season, go check those places out; I’m sure you won’t be disappointed!

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

New! Anahí is starting an Extension Blog in Spanish! Check it out here, extensionesp.umd.edu, and please share and spread the word to your Spanish speaking friends and colleagues in Maryland. Bienvenidos a Extensión en Español!

Hot cocoa, bugs, and forests

Last week my neighborhood hosted the traditional Christmas tree lighting event. Usually this event involves lighting the large Christmas tree across my street, having Santa come visit the kids on the firefighter truck, and sharing a cup of warm chocolate while chatting with the neighbors. This year, things were a bit different, with the lighting being live broadcasted, Santa parading the neighborhood on a truck, and chocolate being picked-up at one of our neighbor’s yard and enjoyed at home.

I have been since thinking a lot about this event, and how important it is to maintain the social ties in our neighborhood. However, I also have been thinking a lot about how the food at this event is almost as important as the event itself; how the chocolate was not left out of this year’s modified event. And this made me realize yet again how foods are central to our social ties, and how losing them would also make us a bit lonelier. So today’s post, the third in our comfort foods series, will be about that food that was so important to my neighborhood this past weekend: chocolate. Join me today in exploring how cacao comes to be, and how partnering with nature helps its (re)production.

cupcakes with chocolate sprinkles
Chocolate – the ultimate winter comfort food. Photo: Kathy Smail

What is cocoa?

The cocoa we find in the chocolate we eat and drink comes from beans of the cacao tree, a small tree in the mallow family. As for the other comfort foods we talked about in my last two posts (spices and vanilla), cacao is also not grown in the USA, and thus has to be imported. (Interestingly, it also has to be 100% imported into the countries we usually associate with chocolate, like Switzerland and Belgium.) Cacao, indeed, can only grow in very humid rainforests and can only be cultivated close to the Equator. Today, the major producers of cacao are in West Africa (e.g., Ivory Coast, Ghana) and the Americas (e.g., Ecuador, Brazil).

cacao tree a the forest
The plant of cacao, Theobroma cacao, is a small tree naturally occurring in South and Central America. The fruits of cacao plants grow directly attached to the trunk. Photo: F. and K. Starr

Even though cultivated in Africa, the cacao plant originates in South and Central America, where the species grows in the wild. Studies demonstrated that the wild plant was domesticated one or two times, first about 5,000 years ago in the Amazon, and about 3,500 years ago in Central America.

Although, as I said before, cacao beans are the central ingredient of chocolate, it is suspected that the first uses of cacao were not based on the consumption of their beans, but rather of their pulp, which is sweet and readily ferments to produce alcoholic beverages. Researchers believe that the use of beans for making the chocolate drinks the first Spaniards saw Aztec emperors drink was indeed a secondary use of the fruit.

How is cacao produced?

Unlike many of the crops we eat, most of cacao production is done by small-scale farmers. Being small trees, cacao fruits are produced in cacao orchards, usually established in areas previously occupied by rain forests. The fruits grow directly on the trunk of the tree, and need to be harvested regularly, since all fruits do not ripen at the same time. Once harvested, the fruits are cut open, and the pulp and beans are separated from the husks. While the husks are discarded, the beans are left to dry out, at which point they become dark and start looking like the little pictures we sometimes see on our chocolate bars.

cacao pod split open
The fruits of cacao are large husks that contain the beans and a sweet pulp. Note the violet/whitish color of the fresh beans, which will eventually turn brown after drying. Photo: Presidencia República Dominicana

As we see, a central part of cocoa production (and us getting the yummy chocolate we like) is the production of fruits, which seems to be defined by many aspects of the production. On the one hand, poor soils lead to yield reductions. Interestingly, cacao trees are adapted to growing in the understory of the rain forest and for this reason had been initially grown under other trees. However, once it was observed that their productivity increased if exposed to full sun, the accompanying trees started to get cut off, further contributing to the deforestation of the rain forests where they are usually grown, and increasing the monoculture of cacao plants.

After some years of higher yield, farmers realized that their trees became less and less productive, and came to understand that the presence of other trees in the orchards maintained the nutrients in the orchard’s soil, what eventually benefited fruit production. Today, in order to maintain yield and sustain the soils, cacao is recommended to be grown in what is called agroforestry systems, meaning that orchards are interplanted with other trees, which enrich the soil with nutrients, and provide a more natural shady environment in which the cacao trees can grow. The little label with a frog that we see on some certified chocolate packages indicates indeed that the farms where the cocoa used in that chocolate was produced following such environmentally friendly practices. Interestingly, as for many environmental practices, it was shown later that using agroforestry methods for cocoa production was not only beneficial to soil fertility; it also indirectly improved fruit pollination, thus improving yield through different paths!

cacao plants
Agroforestry practices allow cacao plants to grow under the canopy of larger trees. This improves the quality of the soil, promotes the presence of pollinators, and leads to higher yield. Photo: J. Rocha, from Rocha et al., 2019

How is cacao pollinated?

Why am I talking about pollination if I was just talking about planting trees? There’s a relationship, I promise! Let’s back up a bit. Unlike other crops (e.g., pecans) most cacao plants need to be cross-pollinated to produce pods and beans. This means that most cacao varieties need to receive pollen from another plant to produce fruit. In the case of cacao, the pollen cannot be transferred by wind, which makes animal pollinators central to cocoa production. In a surprising turn of events, even though we tend to think about pollinators as bees or butterflies, this wonderful fruit is mainly pollinated by a very unexpected organism: a biting midge! 🤯

cacao flower and pollinator midge
Midges of the genus Forcipomyia are the main pollinators of cocoa flowers. These tiny flies visit cocoa flowers and get covered in pollen, as seen in the picture on the left. Photos; left: S. Forbes; right: C. Quintin

Males and females of a group of midges (genus Forcipomyia) act as the main pollinators of the small cacao flowers. These midges visit the flowers to feed on nectar and pollen, which provides energy to the insects and helps females in egg production. While moving from flower to flower to feed, they transfer pollen between flowers from different trees, and increase fruit production. From this perspective, we need to thank these midges for the delicious chocolate we eat and drink!

And this is where planting trees relates to pollination. These midges prefer to develop on humid and shady environments, using leaf litter as a laying site. Making the soils shadier and increasing their leaf residues, agroforestry practices in cacao plantations directly benefit midges’ populations… and cacao production! Thus, through increasing the diversity of trees in these plantations, farmers can both make the soils provide nutrients for the plants to grow, and maintain large midge populations that ensure the effective pollination of cacao flowers. Isn’t it impressive what we can accomplish when we work with nature? And I mean, isn’t chocolate worth it?

Happy Holidays, everybody!

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

Native Solitary Bees: Don’t Make Your Landscape Too Tidy This Fall

ground nesting bee on leaves
Cellophane Bee (Colletes thoracicus) is a solitary bee and valuable pollinator that nests in the ground. Photo by Hadel Go

Cooler evening temperatures might have you switching gears from planting and maintaining your landscape to fall decorating and garden cleanup chores. While cleaning up diseased and pest-infested plants in your yard and garden are important to prevent problems in the future, consider leaving healthy plants that could add visual interest this winter and provide nesting sites for many beneficial critters.

With more than 400 species of native bees in Maryland, these amazing little pollinators are a wonderful addition to your landscape. They are small and not aggressive. Some are specialists, which means they must have certain plants to feed on, while others are generalists and will visit a wide variety of plants. For amazing photos of native bees, check out the USGS Bee Monitoring Lab on Flickr.

As with all members of the animal kingdom, pollinators need food, water, and shelter in order to support life. Successful pollinator habitats include diverse flowering plants, food resources, and safe spaces for creating nests. As you begin cleaning up your yard and garden this fall, remember that these solitary bee species and many other beneficial critters rely on dead plant stems, fallen leaves, and other items that are often traditionally removed from the landscape.

dead plant stalks with new growth emerging at the base
Leave perennial plant stalks standing for the winter. Photo: C. Carignan

According to Colorado State University’s factsheet, Attracting Native Bees to Your Landscape, 90% of native bee species found around the world are solitary. Approximately 70% nest underground in the soil and about 30% nest inside hollow stems of plants and in tunnels left by other insects. Solitary female bees are responsible for collecting food, usually pollen, to include with each egg that she lays throughout the spring and summer. These eggs hatch into larva that spend the winter as pupa, which then turn into adults the following spring. Adult females die with the first fall frost. So in order to continue their life cycle, it is very important that their nesting sites are not destroyed in the fall.

To create friendly bee nesting habitats, provide dead wood like tree stumps or firewood for wood boring bees, plants with hollow stems (brambles and other perennials) for bees that need a tunnel-like structure, and areas of full sun, bare (un-mulched) soil, which ground nesting bees use for their nests.  Landscape fabric prevents ground-nesting bee’s ability to tunnel into the soil.

bee nesting box
Bee nesting box. Photo: Pixabay

Bee houses have gotten some attention in recent years and there are mixed messages about adding bee housing structures. Some evidence suggests that if not properly maintained, these well-intended additions could actually create a negative effect on populations. The houses provide a nice nesting area that results in large numbers of larva/pupa congregated close together, which could be easily targeted by predators, diseases, or parasites. For guidance on bee house maintenance check out this great factsheet from the Xerces Society.

Remember our unseen friends this fall and leave some of your plant materials in place to provide nesting and sheltering sites. Sit back, relax, and delay some of those cleanup chores until spring!

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland, edited by Christa Carignan, Coordinator, Home & Garden Information Center, University of Maryland Extension. See more posts by Ashley and Christa.

Dragonflies bring beauty on the wing

dragonfly resting on a leaf
Dragonflies come in every color of the rainbow and some pretty jazzy combinations. Photo by Joan Willoughby

Dragonflies are amazing insects. Their aerial acrobatics are impressive as is their ability to control pests from mosquitoes to biting flies.

And oh their beauty when shimmering over a garden or pond! Over 5,000 species dress themselves in everything from basic black to electric blue, tasteful stripes to Rorschach ink blots.

Dragonflies first cruised the skies 300 million years ago with 2-foot wingspans. They were among our first winged insects.

Since then they’ve perfected their flying skills. They can move up, down, sideways and backwards, hover and reach speeds of 30 miles per hour. One species migrates 11,000 miles including an ocean crossing.

Several evolutionary adaptations make dragonflies exceptional hunters.

Their head is almost all eyes with over 30,000 facets, allowing them to see nearly 360 degrees. Each of their 4 wings is controlled independently, giving them enviable maneuvering abilities.

Dragonflies and their damselfly cousins comprise the insect order Odonata meaning “toothed ones.”  Watch them hunt and you’ll understand why.

They grab prey in flight using spines on their long legs. Then they use their serrated mandibles to tear them apart and eat them, often while flying. It’s the original dinner to go.

blue dragonfly with large green eyes
Dragonflies’ eyes have 30,000 facets, allowing them to see nearly 360 degrees. Photo by Joan Willoughby

Dragonflies can zero in on one insect in a swarm and follow it with uncanny accuracy thanks to a neural bundle that connects with a flight center in their thorax. They make minute adjustments and – bam – it’s over before that bug knew what hit it.

A Harvard University study showed that dragonflies successfully capture 90 to 95 percent of the prey they pursue.

Mosquitoes, flies, gnats, aphids, bees and other insects may be on the menu. While dragonflies are generalists, they help to control pests and can eat hundreds of mosquitoes a day.

A dragonfly’s life starts in the water. A male dragonfly patrols pond edges looking for food and friendship. When he finds a receptive female, they connect in a heart-shaped flying configuration known as a “mating wheel.”

Is anyone else hearing the theme song from “The Dating Game?”

The female lays her eggs on the water or aquatic plants. They hatch in about a week, becoming aquatic nymphs or naiads.

dragonfly with wings forward sitting on a flower
Dragonflies use plants in and around ponds for perching and egg-laying. Photo by Joan Willoughby

Juvenile dragonflies are as voracious as adults, eating mosquito and other insect larvae, crustaceans, tadpoles, fish, and even other dragonfly young.

Nymphs plod along until dinnertime. Then they blast water through their abdomens to become jet propelled. An extendable jaw snaps forward like a frog’s tongue and nabs unsuspecting prey.

Naiads molt many times during their 2 or more years underwater. Then they crawl out of the water onto a plant or stone and split out of their skin to emerge as adult dragonflies.

Dragonflies need clean water and stable oxygen levels, making them good indicators of a healthy ecosystem. Everything we do to help keep our waterways clean helps dragonflies.

To do more, add a pond or water feature to your landscape. Include some clear surface area and varied plants in and out of the water. Dragonflies will return the favor with natural pest control and beauty on the wing.

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension. This article was previously published by Herald-Mail Media. Read more by Annette.

Firefly or Lightening Bug? You Decide!

firefly resting on butterfly milkweed flowers
Firefly resting on butterfly milkweed flowers. Photo: Pixabay

This summer I have witnessed more fireflies than I’ve ever seen. Each evening gracing our fields and pasture, it is truly unbelievable to see thousands of beautiful and magical flashes of light as night falls. My 4 year old absolutely loves to catch and release the fireflies. It’s wonderful to see the pure delight these stunning beetles bring to both children and adults.

Even more interesting is the fact that these critters are beneficial to our lawns and gardens! They not only provide splendor, but the larvae, which are nocturnal too, spend the majority of their life crawling along the soil surface consuming many harmful garden pests, such as slugs, snails, and cutworms. It takes at least two years for their lifecycle to be complete.

Fireflies are beetles in the Lampyridae family with at least 200 species from 23 genera in North America. Did you know that different species exhibit unique flash patterns, which are not a display for our benefit, but are used to help them attract a mate?

The light that we see is the result of a complex chemical reaction that occurs in the insect’s abdomen. According to the University of Minnesota, the light they produce is a form of luminescence, the emission of light by a substance that has not been heated. There are many ways that organisms accomplish bioluminescence, and the mode that fireflies use is well-understood. Oxygen combines with a substance called luciferin, calcium, and adenosine triphosphate (ATP) in the presence of the enzyme luciferase. The whole reaction takes place in special cells called photocytes. The rhythm of the flashing varies between species and may serve to distinguish males and females from one another.

So what is your preference: firefly or lightning bug? Whatever you decide, be sure to enjoy and appreciate not only their beauty, but also their contribution to helping keep pesky critters in check in our yards and gardens!

Resources & More Information About Fireflies

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland, University of Maryland Extension. See more posts by Ashley.