Whether you associate them with pastel playrooms or cannibalistic serial killers, you've got to admit butterflies and moths are fascinating insects. Even to us gardeners, for whom they're a paradox: When we're not trying to chase them out of our garden, we're scrambling to draw them in.
Butterflies and moths belong to the order Lepidoptera, which is ancient Greek for "scaled wings." The Lepidopterist's Society estimates there may be anywhere between 250,000 to 400,000 species of butterflies and moths, though only about 150,000 species have been officially recorded. This insect order is second in size only to that of beetles.
And given how dependent we are on Lepidopterans for pollination, we've got to treat them all with respect no matter how much beauty — or damage — they bring to our gardens.
Moths vs. butterflies: The lineup
These are the notable differences between moths and butterflies, though there are always exceptions!
- Most moths are nocturnal, while most butterflies are diurnal.
- Butterflies generally have long, thin antennae with small knobs at the ends; moths typically have stubbier, feathery antennae.
- When butterflies are chilling out, they "tent" their wings above their bodies while moths usually lay them flat.
Moths make up roughly 85% of the Lepidopterans, and while they're usually thought of as the butterfly's plain Jane cousin, there are moth species with spectacular patterns and colors, just as there are boring-ass butterflies. Moths play as critical a role in pollination as do butterflies, particularly those that do their jobs when all other pollinators are passed out for the night.
Butterflies and moths as niche pollinators
There might be nearly half a million Lepidoptera out there, but moths and butterflies tend to be specialists. That means that if a species is wiped out, its ecosystem suffers.
Many butterflies and moths are monophagous, meaning they rely on single plant species to survive. The adults feed on the nectar, lay their eggs on or around the plant, and the larvae can only thrive on its leaves or sap. Most of us know about the relationship between Monarch butterflies and milkweed. It's a mostly one-sided relationship; while monarchs pollinate milkweed, so can other insects. But some plants depend on a single insect species or type to reproduce. The yucca plant can't live without moths in the Tegeticula genus, and vice-versa. Yucca moths don't eat in the adult phase, but, like mason bees, they gather pollen to store near their eggs.
Moths and butterflies that do eat during the adult phase have long, thin proboscises that can access nectar off-limits to other pollinators. Even then, they might have to work at it, dusting themselves with pollen for transport to other flowers in the same species.
How Lepidopterans are important to our greater ecosystem
Caterpillars are packed with protein and nutrients and are a major food source for birds, mammals, fish, reptiles, amphibians, and other bugs. Some species, such as the shea caterpillar (Cirina butyrospermi), are taking hold as environmentally-friendly, sustainable commodities for human consumption. Flying adults help sustain birds and bats. Seed-eating birds, of course, benefit from the pollinating services butterflies and moths provide, and without butterflies, there would be far fewer plants to feed and shelter other insects and critters. In short, we'd all be screwed.
They give a s**t, and that's a good thing
Even the worst plant predators give back. Frass is another name for caterpillar poop, and that left behind by the fall armyworm (Spodoptera frugiperda) may unlock new recipes for organic pesticides and fungicides. Some Lepidopterans, like the Mediterranean flour moth (Ephestia kuehniella), excrete antimicrobial chemicals in their poop, and researchers are looking into ways to use frass to combat diseases that are becoming resistant to medicine and biohazard cleaning compounds.
Have you ever treated your garden to worm castings? Caterpillar frass is also high in nitrogen. Nobody wants to attract caterpillars to their gardens for the specific task of fertilizing their plants — for obvious reasons — but should caterpillar farming for human food production really catch on, frass could be a very lucrative byproduct.
Grow these host plants to attract butterflies and moths
Butterfly gardens are gorgeous with or without their fluttery guests, and they serve multiple practical purposes. They can draw problem bugs away from high-value ornamentals, herbs, fruits, and vegetables attract a broader range of wildlife species, and of course, provide habitat for future generations of essential pollinators.
Whenever possible, select plants that are native to your region and stagger bloom times to cover early spring through fall insect populations. The best butterfly plants provide nectar for adults and munchy greenery for caterpillars. Milkweed (Asclepias spp.) offers both for monarchs (Danaus plexippus), and in spite of its super lame name, it's an attractive ornamental available in a wide variety of bright and pastel colors.
Milkweed also attracts the milkweed tussock (or milkweed tiger) moth (Euchaetes egle). The disgustingly adorable orange and black caterpillars sport jaunty white tufts, and while the adults are perhaps the most boring looking bugs on the planet they've adapted an organ that emits sonic alarms to bats, which in turn have evolved to learn that the noisemaker isn't a worthy treat. Milkweed sap contains a mildly toxic (but safe for humans and pets) compound, and when caterpillars eat it, the chemicals remain throughout their life cycle, leaving them with an unpleasant taste.
We showcased milkweed because of it's importance to monarchs and attractiveness to a wide variety of species. We'll let you explore the rest on your own. Here are a few of our favorite butterfly- and moth-friendly plants:
- Aster (Aster spp.) Nectar, host
- Black-eyed Susan (Rudbeckia hirta) Nectar, host
- Borage (Borago officinalis) Nectar, host
- Butterfly bush (Buddleia davidii) Nectar, nocturnal blooms
- Chocolate daisy (Berlandiera lyrata) Nectar, nocturnal blooms
- Coneflower (Echinacea purpurea) Nectar, host
- Cosmos (Cosmos spp.) Nectar
- Datura (Datura wrightii) Nectar, nocturnal blooms
- Dianthus, single-flowered varieties (Dianthus spp.) Nectar
- Dill (Antheum graveolens) Host
- Evening primrose (Oenethera spp.) Nectar, host, nocturnal blooms
- Fennel (Foeniculum vulgare) Host
- Four o'clock (Mirabilis jalapa) Nectar, nocturnal blooms
- Marigold (Tagetes spp.) Nectar
- Nasturtium (Tropaeolum majus) Host
- Night-blooming jasmine (Cestrum nocturnum) Nectar, nocturnal blooms
- Passionflower (Passiflora spp.) Nectar, host
- Thistle (Cirsium discolor) Nectar
- Yarrow (Achillea spp.) Nectar
- Zinnia (Zinnia elegans) Nectar
The North American Butterfly Association recommends creating a diverse ecosystem of shrubs, trees, and landscape features for your butterflies and moths. Lepidopterans need shelter from wind, sun-warmed perches such as logs, stones, or mulch to help get their juices flowing in the morning, and safe sources of water. A damp, clay-like patch of ground near a dripping garden hydrant is perfect. Like many other insects, butterflies and moths engage in "mud-puddling," when they hang out on the edge of a stream, pond, puddle, or seep to suck up mineral-rich moisture. Just be sure no chemicals have leached into your offered water supply!
Tips for managing caterpillar populations
Maybe you did too good a job attracting butterflies and moths to your garden, and now you're overrun. Pesticides are a no-no, as they don't discriminate between the good, the bad, and the ugly.
You can protect tender crops with floating row covers, create habitat to attract grub-eating birds, or grab a pair of gloves (some caterpillars can irritate the skin on contact) and a container, and pick off unwanted larvae by hand as you go about your garden chores.
If you're squeamish about destroying caterpillars, do what we do: Plant some host plant species in an area away from your main garden and let the little buggers munch away and complete their life cycles in peace. Or, if you have ducks or chickens, they'll happily snack on surplus caterpillars. They might not be the brightest birds, but they manage to ignore bugs that aren't good for them. (You'll find they're not fans of the fuzzies.)
Love to go fishing? Caterpillars make fantastic bait!
Moths earned a bad rap for destroying cotton and linen clothing or raiding pantries to invade stored flour and grain, but the winged adults aren't the ones doing the damage. Adult Lepidopterans eat only nectar, and some don't eat anything at all. Butterfly and moth larvae eat plant solids.
And boy, do they ever.
It makes sense that moth caterpillars do more damage than butterfly larvae, given that there's about an 8:1 ratio between the species. Here are some of the nastiest:
- Cabbage looper (Trichoplusia ni)
- Corn earworm (Helicoverpa zea) not to be confused with Korn earworm (Metalus bakersfieldii)
- Cutworm, a name assigned to stem-destroying moths from several genera
- Diamondback moth larvae (Plutella xylostella)
- Tomato hornworm (Manduca quinquemaculata)
Useful caterpillar, moth, and butterfly guides
Ready to learn more? Here are a few sites we keep bookmarked at Seed Needs for when customers send us "WTF is this?" requests for bug identification.
- North American Caterpillar Identification on Owlcation
- The Butterflies and Moths of North America (BAMONA) project
- Iowa State University's BugGuide.Net
- University of Florida Insect ID Lab
- Insect Identification for the Casual Observer
You can't go wrong with analog! Every gardener should have a field guide nearby. Best Reviews can help you choose the best reference for you.
Enhance your backyard habitat with Seed Needs
Whether you're growing flowers to attract butterflies for their beauty or to boost your local pollinator population, check out our online catalog. We have butterfly garden seed collections and colorful milkweed varieties, and of course, our seeds are as fresh and robust as they come. We only stock enough seeds as we can expect to sell within a given season, and we source all our products from reliable producers of high-quality plant genetics.