Rising Carrots and Different Hosts for Black Swallowtail Butterflies


Are you curious about rising carrots and different backyard crops to draw black swallowtail butterflies?

These pollinators could make their houses in our gardens at many alternative levels of their lives. They’re a sight to see within the yard or backyard – each of their larval varieties and after they take flight as winged beauties!

A close up horizontal image of a black swallowtail butterfly larva eating a carrot plant.

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Whether or not you wish to discover ways to entice these pollinators to your yard or are questioning if the caterpillars are going to harm your carrots or different crops, on this article we’ll present the solutions you’re searching for.

Able to study extra about these caterpillars and their meals preferences? Right here’s what we’ll cowl:

What Are Black Swallowtail Butterflies?

The black swallowtail butterfly (Papilio polyxenes) is a good looking winged insect whose native vary is within the japanese, central, and southwestern areas of the USA.

These lepidopterans, members of the taxonomic order Lepidoptera, consisting of butterflies and moths, are additionally present in Canada in Quebec and Saskatchewan, in addition to in Central America and the northern a part of South America.

A close up horizontal image of a black swallowtail butterfly feeding from a yellow flower.
Black swallowtail (P. polyxenes).

They’re massive flying bugs, with a wingspan of three and 1 / 4 to 4 and 1 / 4 inches.

Like different species within the Papilionidae or swallowtail butterfly household, these creatures have distinctive lobes on their rear wings, harking back to the tails of swallowtail birds.

Also called American swallowtail, caraway worm, celery worm, parsley swallowtail, parsley worm, or parsnip swallowtail, these butterflies have distinctive markings on each the highest sides and the decrease surfaces of their wings.

Wings have a black background, and each men and women have a single reddish-orange spot with a black bullseye on the again central edge of every wing. These dots are seen on each the higher and decrease wing surfaces.

A close up horizontal image of a female black swallowtail butterfly feeding on a pink flower pictured on a soft focus background.
Feminine black swallowtail butterfly.

On the highest surfaces of the wings, men and women have a row of yellow dots close to the perimeters.

Above these yellow dots, females have a band of blue markings, and small, pale yellow dots above the blue.

A close up horizontal image of a male black swallowtail butterfly on a plant.
P. polyxenes male.

Males, alternatively, have faint blue dots, with a band of enormous, yellow dots above the blue.

The undersides of the wings look the identical on male and females – and you might not have realized that there are literally two units of wings, the forewings and the hindwings.

A close up horizontal image of two black swallowtail butterflies feeding on yellow lantana flowers pictured on a soft focus background.
Female and male P. polyxenes foraging collectively.

When the wings of those bugs are closed, the underside surfaces are revealed, displaying two rows of pale yellow dots on the forewings, and on the hindwings, a powdery trying shading of pale blue between two rows of orange markings.

The Black Swallowtail Life Cycle

If you wish to assist these pollinators by rising carrots in your backyard, you’ll must know the way to acknowledge them not solely of their grownup type, however in any respect levels of their life cycle.

In any case, you possibly can’t have butterflies with out caterpillars!

This parsley worm life cycle consists of 4 major levels: egg, larva, pupa, and grownup.

Parsley Worm Eggs

Figuring out the way to acknowledge the eggs of those lepidopterans is essential, particularly as you go about harvesting your backyard herbs – and veggies corresponding to carrots.

Grownup feminine butterflies lay spherical, pale yellow eggs on host crops.

A horizontal image of black swallowtail butterfly eggs on carrot foliage pictured on a soft focus background.
Eggs on parsley leaves, not but able to hatch.

About 9 days later, the eggs will hatch. Shortly earlier than hatching although, the eggs flip a darkish coloration, virtually black.

You’ll study extra about which host crops are favored later on this article, however these within the carrot household, Apiaceae, corresponding to parsley are clear favorites, so remember to examine the foliage for eggs earlier than harvesting.

Fortunately, most of us are harvesting our herbs in a cut-and-come-again type, so there ought to be loads of foliage to share, permitting you to depart any parsley worm eggs safely hooked up to the foliage.


After the eggs hatch, small caterpillars emerge and through a interval of 10 to 30 days, these larvae reside and feed on host crops, and are solely round a sixteenth of an inch lengthy.

Throughout this larval interval, caterpillars develop into 5 totally different levels, known as instars.

As they transition to every new instar, the larva molts, leaving its outdated pores and skin behind and rising larger than it was earlier than.

First Instar

First instar larvae, that’s to say the youngest and tiniest parsley worm caterpillars, are black with a white mark within the center, sometimes called a saddle.

A close up horizontal image of a first instar of a black swallowtail caterpillar pictured on a soft focus background.

They’re about an eighth of an inch lengthy, and still have orange spots and black spikes.

This coloration serves as camouflage, making these caterpillars look very very like hen droppings!

Second Instar

As larval caterpillars develop, they enter the following stage referred to as the second instar, reaching a few quarter of an inch lengthy.

A close up horizontal image of the second instar of a black swallowtail caterpillar on a leaf.
Second instar parsley worm.

On this stage the caterpillars are black with orange spots and black spikes which are literally hairs. The white saddle is not very distinct.

Third Instar

When one in all these caterpillars molts and emerges as a 3rd instar, it’s vibrant inexperienced or white with black stripes and orangish yellow spots.

A close up horizontal image of the third instar of a black swallowtail caterpillar munching on carrot foliage.
Third instar.

At this stage, the parsley worms nonetheless have little spikes on their our bodies and are about half an inch lengthy.

Fourth Instar

Of their fourth instar, the striped coloration is extra outlined, and it grows even bigger and now has white prolegs with black dots.

The spikes on the physique are not current and by this stage the caterpillars are round an inch lengthy.

A close up horizontal image of a caterpillar consuming its shed skin after molting.
Fourth instar, consuming its molted pores and skin.

All through the larval levels, after parsley worms step out of their outdated skins, they use these discarded layers as a nourishing meal.

Fifth Instar

The fifth instar is the final larval stage.

A close up horizontal image of a black swallowtail caterpillar feeding on a fennel stem, pictured on a soft focus background.
Fifth instar.

On this section, these caterpillars are a lot simpler to identify within the backyard due to their massive measurement, at this stage they’re about two inches lengthy.

You will have had these larvae residing on the carrots in your backyard with out noticing them till now!


After the fifth instar, the caterpillar is able to pupate, starting its metamorphosis right into a butterfly.

A close up horizontal image of a pupating black swallowtail caterpillar on a branch, pictured on a soft focus background.
Pupating celery worm caterpillar.

To anchor itself for this section, the caterpillar attaches itself to a stem with a silk sling, with its head pointed upwards.

Inside a day or two, it would shed its pores and skin but once more, revealing the chrysalis.

A close up horizontal image of a chrysalis of a black swallowtail butterfly on a stem pictured on a dark background.
P. polyxenes chrysalis.

The chrysalis may be inexperienced or brown, relying on the season and the kind of stem the pupa is anchored to. The colour of the chrysalis will mix into its environment.


Throughout spring and summer season, the pupal stage lasts for as much as 18 days. Some pupae additionally overwinter, ready for spring earlier than popping out of their chrysalises.

A horizontal image of a black swallowtail butterfly emerging from a chrysalis pictured on a blue sky background.
Butterfly rising from chrysalis.

As soon as a butterfly emerges from its chrysalis, this flying bug with a three- to four-inch wingspan is able to begin searching for a mate.

Females then lay eggs on host plant materials corresponding to carrot leaves and the cycle continues.

Do Parsley Worms Harm Carrots?

Now that you know the way to acknowledge these fascinating bugs in all their life levels, are you questioning if they’re backyard pals or foes?

Black swallowtail butterflies are thought-about pollinators, though they will not be fairly as environment friendly at this process as bees.

A horizontal image of a black swallowtail butterfly landing on a yellow wild parsnip plant pictured on a soft focus background.

Whereas they will not be as environment friendly as bees for pollinating crops, since butterflies fly lengthy distances, they assist guarantee genetic range in crops by transferring pollen from flower to flower.

Meaning we should always contemplate them to be useful bugs in our gardens to some extent!

In fact, then we have now to contemplate any harm that black swallowtail butterfly larvae may do to our crops.

A horizontal image of black swallowtail caterpillars feeding on fennel plants in the garden.

There needs to be appreciable harm to the crop earlier than pesticide use is warranted – one thing that enormous scale farmers are nicely conscious of, however yard gardeners might not contemplate.

Typically, the presence of parsley worms doesn’t do sufficient harm to crops to warrant contemplating them as pests.

Nonetheless, when these caterpillars are quite a few within the backyard, there are occasions when they could eat extra herbs or veggie greens than you had hoped.

To stop crop loss, quite than resorting to chemical controls, think about using obstacles to maintain these bugs away from crops you might wish to defend, corresponding to carrots.

Pest Management Pop Ups are cages made with metal helps and nylon mesh cloth that assist preserve adults from touchdown in your crop to put eggs.

A close up square image of a raised garden bed with pest control pop up protectors.

Pest Management Pop Ups

Pest Management Pop Ups can be found in three sizes: two-by-two toes, four-by-four toes, and four-by-eight toes. You should purchase them from Gardener’s Provide.

If you have already got caterpillars munching in your crops and are searching for an moral resolution to defending your herbs or veggies, contemplate relocating these bugs to wild host crops corresponding to Queen Anne’s lace.

Preserve studying to study extra host plant choices for these pollinators – that’s our subsequent subject!

Carrots and Different Host Vegetation for Parsley Worms

You now know what to anticipate from these butterflies, and it’s time to discover ways to entice them by offering them with meals in a wildlife-friendly backyard.

These butterflies use umbellifers – also referred to as Apiaceae or members of the carrot household – and different comparable crops as larval host crops.

A horizontal image of a black swallowtail butterfly laying eggs on a flowering dill plant.
Feminine laying eggs.

Are you questioning what the time period “host plant” means precisely?

When females are mature and able to lay eggs, they search out egg-laying places that can present appropriate meals, referred to as host crops, for his or her offspring.

Some bugs want particular kinds of crops for his or her infants.

Carrots are a favourite host plant, however they aren’t the one choice. These butterflies also can use different members of the carrot household which might be widespread in vegetable gardens together with parsley, fennel, and celery.

One other carrot relative, dill, is widespread with these bugs and different useful bugs as nicely – I wouldn’t develop a wildlife-friendly backyard with out it!

A close up of a packet of Bouquet dill seeds with a hand-drawn illustration on the right of the frame and tex to the left.

Bouquet Dill Seeds

You could find packets of dill seeds accessible at Botanical Pursuits.

Along with Queen Anne’s lace, there are another carrot relations that may function hosts for black swallowtail butterfly larva as nicely.

These embody poison hemlock (Conium maculatum), water hemlock (Cicuta maculata), wild parsnip (Pastinaca sativa), and golden alexander (Zizia aurea).

Golden alexander is a wildflower within the carrot household that’s indigenous to japanese and central North America and can be utilized in native plant landscaping to assist assist wildlife.

A square image of a golden alexander flower pictured on a soft focus green background.

Golden Alexander Dwell Vegetation

You’ll discover golden alexander crops at Nature Hills Nursery.

Different crops apart from members of the Apiaceae household can function larval hosts for parsley worms too.

These embody some crops within the citrus household, Rutaceae, corresponding to mock bishopweed (Ptilimnium capillaceum), roughfruit scaleseed (Spermolepis divaricata), water cowbane (Oxypolis filiformis), and wedgeleaf eryngo (Eryngium cuneifolium).

Extra Suggestions for Supporting Black Swallowtails

Whereas offering these butterflies with carrots and a few of their different favourite host crops will go a good distance towards supporting them, there are extra actions you possibly can take as nicely.

A close up horizontal image of a butterfly feeding from purple coneflowers growing in the summer garden.

The host crops listed above are species that the swallowtail caterpillars can subsist on – however swallowtail butterflies want nectar!

Adults can forage from a variety of crops together with clover, cosmos, milkweed, phlox, thistles, zinnias, and purple coneflowers.

A square image of purple coneflowers growing in the garden.

Dwell Purple Coneflower Vegetation

You could find purple coneflower crops accessible at Nature Hills Nursery.

Along with offering nectar crops, it’s essential to keep away from utilizing each pesticides and herbicides in your yard and backyard.

Even licensed natural pesticides like neem oil will hurt these pollinators, so attempt to take different measures earlier than making use of something which may be poisonous.

Wish to study extra? Learn our article to study extra about built-in pest administration.

Extra Butterflies, Extra Magnificence

As you’ve discovered at present, black swallowtail butterflies love to put their eggs on members of the carrot household, which offer meals for his or her younger.

These caterpillars don’t normally represent a pest drawback on carrot crops, but when mandatory, they are often excluded from crops with cages or relocated to different host crops.

A close up horizontal image of a caterpillar feeding on carrot foliage.

Are you making an attempt to draw parsley swallowtails to your yard?

Inform us about your reference to these lovely butterflies within the feedback part under – and when you’ve got any questions, remember to drop them there too!

And whilst you’re at it, why not share pictures of the parsnip swallowtails in your backyard patch?

Whilst you’re right here, do you want extra suggestions for rising a bountiful carrot crop? We now have loads of suggestions for you proper right here: