Beneficial Insects: Fireflies

Let’s talk about fireflies! These beautiful insects enamor kids and adults alike. It’s hard not to love how they light up the night, but there’s more to fireflies than beauty! They are wonderful for gardens. They’re native predators that feed on common garden pests like slugs and snails. Keep reading to learn about some firefly species you might see, their lifecycle and benefits, and how to attract them to your garden. 

Firefly Species of the Southeastern United States

The name firefly doesn’t refer to a single species. There are over 2,000 species of fireflies worldwide, and about 175 are native to North America! Here are some of the incredible firefly species you might see if you live in our region, the Southeastern United States:

  • The Common Eastern Firefly or Big Dipper Firefly (Photinus pyralis)
    Males produce a single sustained yellow light, often in a J-shaped flight trajectory.
  • The Blue Ghost (Phausis reticulata)
    Males glow with a pale blue or green light rather than flashing.
  • The Synchronous Firefly (Photinus carolinus)
    All individuals in an area will display 5 to 8 flashes of yellow light followed by a period of darkness for 8 to 10 seconds.
  • Father Mac’s Firefly or Mr. Macs (Photinus macdermotti)
    Males display two flashes of yellow light about 1 1/2 to 2 seconds apart, followed by 4 to 5 seconds of darkness, then another double flash.
  • The Spring Four-Flasher (Photuris versicolor var. quadrifulgens)

    These fireflies display in spring with a stuttered four-part flash. 

Next time you watch fireflies, see if you can spot any recognizable flash patterns! Of course, there are also many other species of fireflies you can learn to identify. Finding an insect field guide can be helpful (check your local library), or check out resources that the Firefly Atlas has listed.

Blue Ghost Firefly
Aggyrolemnoixytes, CC BY-SA 4.0 <>, via Wikimedia Commons

Beyond Beauty: Understanding Fireflies

While you might already want to attract fireflies to your garden just for their looks, there are a few other reasons they’re great to have around.

Fireflies have a four-part lifecycle: egg, larva, pupa, and adult. The entire lifecycle can last two months to three years, depending on the species, with the longest period spent in the larval stage.

Firefly larvae live in moist soil, feeding off slugs, snails, and other soft-bodied insects. They’re an excellent garden ally! All firefly larvae are bioluminescent, which may help ward off predators.

After that stage, they pupate in safe spots like underground, rotting logs, or bark furrows. They overwinter in this stage and emerge in the spring as adult fireflies that light up the skies. Depending on the species, adult fireflies may feed on nectar, pollen, other fireflies or not eat at all.

Not all adult fireflies produce flashes. In those that do, the flash is made by chemicals like luciferase and luciferin, working with other substances in the insect’s body to produce light in the firefly’s lantern organ on their abdomen. 

The flashes, often created by males while flying, are signals to find mates. Different species have different flash patterns and sometimes different colors so that they can find a mate from the correct species.

Thanks to fireflies, scientists have created a test for harmful bacteria like salmonella or E. coli in food products such as milk, soft drinks, and meat. The test contains luciferase and luciferin, which react with any ATP found in bacteria cells (and all living cells). A glowing test means bacteria is present.

How to Encourage Fireflies in Your Garden

Unfortunately, many firefly species are in decline. They have been affected by habitat loss, climate change, and pollution. Now that we have some basic knowledge about the firefly lifecycle, we can consider what would make our gardens and yard attractive to them. 

Avoid Pesticides, Herbicides, and Other Chemicals

Some of this goes without saying; obviously, spraying your garden and home with pesticides is detrimental to all the species that live there. Pesticides (even organic ones) don’t discriminate between good bugs and bad. 

Other chemicals, such as herbicides and fungicides, can also linger in the soil, affecting firefly populations for years to come. Always thoroughly research any product you intend to use in your garden.

Synchronous Fireflies
Firefly Photos by Radim Schreiber;, CC BY-SA 3.0 <>, via Wikimedia Commons

Improve Soil Health

Much like your plants, firefly larvae thrive in rich, moist, loose soil with plenty of organic matter. Good soil isn’t built overnight, but there are many free or cheap ways to improve it. Consider adding compost and leaf litter to your garden. You can also use methods like broad forking, no-till gardening, and cover cropping. 

Natural Spaces

Even if you nurture a suitable habitat in your garden, it’s always a good idea to consider keeping some space wild if you have a suitable property. Rotting logs, leaf litter, and weedy native plants may seem unsightly to some but are attractive to our firefly friends and other native species. 

Minimize Outdoor Lighting

Many scientists believe light pollution interferes with firefly mating and probably contributes to their decline. Minimizing outdoor lighting at night can give those in your area a better chance. Plus, it also helps migrating birds!

Consider closing curtains in brightly lit rooms and turning off outdoor lighting when not in use. You may also consider switching to motion detector lighting for the outdoors, which can still help with security and provide automatic light whenever you need it.

Don’t Remove Leaf Litter

Leaf litter provides an essential habitat for fireflies and other beneficial insects. When you rake up leaf litter, you remove organic matter from your soil and rake up firefly larvae!

Leave Riparian Areas Natural

Don’t mow near the edges of ponds, creeks, and rivers any more than you have to. A small patch for access is fine, but mowing the whole thing eliminates habitat and contributes to erosion and water pollution. 

Plant Native Species and Encourage Variety

When possible plant native species to support all kinds of native wildlife and insects. You can also improve the habitat, even in areas where you are growing non-natives, by encouraging diversity. Avoid aggressive invasive plants and monocultures. Instead, opt for a mix of plants with varying heights, textures, and blooms.

Fireflies bring a lot of joy and purpose to your garden. Help them thrive by keeping these practices in mind this season.

Organic Slug Control

Many of our customers occasionally struggle with pests. Unfortunately, they’re a part of gardening! One common issue we see, especially in spring and early summer, is slug damage. These slimy little creatures are active at night and during cool temperatures, snacking on your plants, especially young, tender foliage. They can take out entire seedlings or reduce your harvest from tasty crops like tomatoes and strawberries. Learn how to identify and combat a slug problem with organic methods. 

Signs of Slugs

  • Shiny slime trails across leaves and the ground.
  • Irregularly shaped holes in leaves, flowers, and fruit.
  • Look for slugs at night or on rainy days.
  • Look for slugs under lower leaves, boards, and other cool, moist shelters.

Deter Slugs

Slugs thrive under certain conditions. To prevent them from becoming an issue, avoid making your garden an attractive habitat for them. 

Here are some ways to deter them:

  • Prune lower branches and foliage to encourage air circulation and sunlight.
  • Stake plants like tomatoes to encourage air circulation and keep fruit off the ground. 
  • Divide or thin plants to encourage air circulation and sunlight.
  • Remove natural mulch, like old leaves, at least temporarily.
  • Add compost to beds, improve soil, and improve drainage to help combat wet conditions over time.
  • Remove places where slugs could hide, like containers, flats, stones, boards, etc.
  • Use water-wise gardening techniques like drip irrigation or soaker hoses to minimize excess moisture. 
European Starling
European Starlings are not native to the U.S. but are common in the southeast and are incredible slug predators.

Attract Predators

In the long term, attracting slug predators can also be an effective way to manage slugs. We think they look a little slimy, but many creatures, such as slugs, beetles, toads, turtles, snakes, ducks, and certain songbirds, find them to be a tasty treat. Providing habitats for these animals within your garden can encourage them to stay and eliminate slug populations.

Handpick or Trap Slugs

One of the simplest ways to get rid of slugs is to handpick them. Put on some garden gloves and head out at night with a flashlight for a bit of slug hunting. Then, crush the slugs or toss them into a bucket of soapy water.

While we previously mentioned getting rid of slug homes like boards, you could add them to make the perfect trap. Each morning, flip your board and kill any slugs you find. 

Another classic method for dealing with slugs is the good old-fashioned beer trap. Take small containers or dishes and bury them a bit in the garden so the top is level with the ground. Then, fill them with beer or a water and yeast mixture. The slugs will be attracted to the beer or yeast mixture, fall in, and drown. If you have a serious problem, you may need to put out a good number of traps and change them daily.

Organic Slug Baits & Deterennts

Coating plants with a heavy dusting of diatomaceous earth can help keep slugs at bay. However, it must be reapplied frequently and isn’t always a great long-term solution.

Copper foil or bands are another effective slug deterrent. While they can easily be affixed to a single raised bed, they may not be an efficient choice for large gardens.

You can also purchase organic baits like Sluggo, which is OMRI-certified. If you want to use slug bait, this is a good option because it’s safe for pets and non-toxic. It’s made from iron phosphate.

Many other slug baits are toxic to other animals, including pets and young children. Always select and use garden products carefully.

We always aim to work with nature to create beautiful, bountiful gardens. Unfortunately, pests will always be an occasional issue in any garden, whether organic or conventional. Thankfully, slugs are a relatively easy pest to deal with, and you can use these simple strategies to deter and eliminate them.

Ants on Your Plants: Are They Bad for the Garden?

When you start gardening, you’ll probably start noticing more of the life that visits your yard. For most non-gardeners, insects only come into focus when they enter houses, but for gardeners, they suddenly play a bigger role on stage. You start noticing the earthworms in the soil, the pillbugs scurrying around in your mulch, and the slugs that come to chew big holes in your kale. Many folks will spot ants visiting their garden and wonder what they’re doing there. Are they pests or garden allies? 

Why Are There Ants on My Plants?

Ants may be visiting your garden for several reasons. Like us, they must meet a few essential needs to survive: moisture, food, and shelter. These needs are met in different ways depending on the species of ant, and there are almost 800 ant species found in the United States today! Though these species vary widely, below we’ll cover some of the more common reasons you’ll spot them on your garden plants. 

Collecting Water

The way that ants source water varies with species. Some ants are specifically adapted to get all their moisture needs from their food sources. Harvester ants, for instance, can get most of their moisture needs from seeds, while other ants may get most of their moisture from flower nectar. 

However, it’s not unusual for ant species to gather water from dew droplets or puddles. If you often spot ants visiting your plants that tend to collect dew, they could be harvesting the water. 

Ant farming aphids on a plant stemFarming Aphids, Scale Insects, and Mealybugs

Many ant species, including Argentine ants (Linepithema humile), Allegheny mound ants (Formica exsectoides), common citronella ants (Lasius claviger), and longhorn crazy ants (Paratrechina longicornis), all enjoy feeding on honeydew, a rich, sugary substance secreted by aphids, scale insects, and mealybugs as they feed on plant sap. 

These ants will go to great lengths to ensure a steady supply of honeydew. The ants actually farm the aphids and other insects almost the way we do livestock. They will protect the aphid colony, keeping their habitat clean and fighting off predators. They also cull certain insects, especially older ones, that produce less honey-dew. When they want to collect honeydew, they gently tap the insect’s abdomen to encourage them to secrete honeydew. 

Amazingly, ants will also carry these insects to new plants to increase production. Obviously, this behavior can be problematic for gardeners. 

Thankfully, aphids are usually a reasonably easy pest to eliminate. A strong jet of water to kill or blast the aphids off the plant may be enough to do the trick. You can also use insecticidal soap or soapy water to kill the aphids. However, this method comes with some risks. It can destroy the waxy coating on leaves and may burn foliage, especially during hot and humid weather.

Harvesting Other Sugary Foods

Many of the ants that enjoy honeydew also love other sugary foods, such as flower nectar, fruit juices, and human food scraps. While the ants may seem like a nuisance if they show up at your picnic or climb into your flowers to gather nectar, they don’t do any harm. Usually, they don’t harvest fruit or juices unless the produce is already damaged. 

For example, finding ants in a hole in strawberries is often a significant complaint. Interestingly, it’s not typically the ants making the hole. Usually, slugs eat strawberries and other fruit at night, and then the ants harvest from the opening that the slugs have created during the day. Usually, if you can eliminate the slugs, the ants will cease to be an issue. 

Line of ants carrying leavesLeaf Cutters

You may also see leafcutter ants like the Texas leafcutter ant (Atta texana) in certain parts of the United States. These interesting ants can often be seen carrying large pieces of foliage back to their nests. This particular species has been known to work together as a colony to defoliate a citrus tree in less than 24 hours!

These foliage foragers aren’t eating the leaves; they take them back to their nest and chew them into a paste as fertilizer for their fungus gardens. Regardless, they can spell trouble if you’re trying to grow plants and trees within a colony’s range. 

Unfortunately, for people coping with leaf-cutter ants, many of the organic “ant baits” you see recommended aren’t effective because these species only feed on the fungus they grow in their nest.

We don’t have personal recommendations because they aren’t an issue for us. However, many permaculturalists in other areas recommend raising guinea fowl or treating the nests with boiling water. 

Harvester Ants

Harvester ants collect grains and seeds, which they store in granary areas within their nest. These ants aren’t usually a significant issue for vegetable gardeners, though you may observe them gathering seeds from plants around you. They can be an issue for grain farmers.

Benefits of Ants

While we may sometimes butt heads with ants and other creatures in our garden, it’s important to remember that they have their place. There are several benefits to ants that many gardeners and nature lovers can appreciate.

  • Many ground-dwelling species, like northern fungus-farming ants (Trachymyrmex septentrionalis), aerate the soil and improve fertility. These industrious ants bring minerals and nutrients up from deep below the surface, making them accessible to trees and plants.

  • Many ants, like large imported big-headed ants (Pheidole obscurithorax), are voracious predators of other pests. Researchers have found that one species, Buren’s Pyramid Ant (Dorymyrmex bureni), often feeds on invasive fire ants (Solenopsis invicta).

  • Some ants, like American winter ants (Prenolepis imparis), plant wildflowers. About 11,000 plant species, including many native wildflowers like bloodroot, trillium, and violets, have developed seed appendages that attract ants, encouraging them to harvest the seeds and transport them to new locations.

  • Ants clean up carrion, food scraps, and other waste, helping reduce the number of flies and other animals attracted to a location.

  • Some ants, like black harvester ants (Veromessor pergandei), help landscapes recover from wildfires, drought, and overgrazing. Researchers have found that the rims of their nests are “islands of fertility.” In these fertile soils, plants recover more quickly and help re-seed the nearby landscape. 

Depending on the species, seeing insects in the garden can bring joy and worry. Hopefully, this will help you understand why you’re seeing ants in your garden, what they’re up to, and what steps you may need to take. 

Saving the Past for the Future