Pesticide is a fearful thing when we’re raising butterflies and moths.

When we buy a plant or think our plants may have been treated with pesticides, we test the plant on one or two caterpillars before feeding it to all the caterpillars we are raising.  But the question is WHEN do we know a plant is safe to feed to caterpillars?  If the caterpillars are alive the next day, is the plant OK?

The answer is a simple and resounding NO.  Some pesticides will kill immediately.  Others take a day or two.  Some take three days (such as Bt).  Others will slowly kill them, by interfering with their mandibles and how much they can eat (lack of nutrition).  Yet others won’t affect them at all until they begin to pupate and won’t be able to finish the pupation process.

If caterpillars are fed some pesticides just before they pupate, they will emerge fine, inflate and dry their wings, and begin to fly before falling to the ground, quivering and dying with their wings folded downward over their legs.

The only fully correct answer is that a caterpillar should be fed the plant and it considered unsafe until it emerges and lives a day as an adult.  BUT …

In most cases, after a caterpillar that has been eating the plant has successfully and fully pupated, it is safe.  

That isn’t the answer we hoped for but it is the answer we want, the one that will help prevent more deaths.

Sometimes we need to take eggs off a plant before they hatch.  Depending on the species, we may disinfect the eggs or we may simply want to move them off a large plant so we can place them on a smaller plant.  What next?  Where to place them?

We use a plastic cup, from 2 to 5-1/2 ounce size.  The eggs are placed in the cup.  Once the eggs start to darken, we either place fresh tender leaves with the eggs, place the cup in a popup with the tip of the plant in the cup, or attach the cup to the plant we want them to eat.

Once they hatch, they go immediately to the  plant and begin eating.

Click here to see the popup habitats we use for caterpillars.

Reminder: After petting cats or dogs with oral (or topical) flea/tick medication, wash your hands well before touching caterpillars or their food.  The medication is actually a pesticide that kills fleas and ticks.  It gets into the dog’s body system, coming out in its skin oils and dander.  When we pet them, we get it on our hands.

Some of the medications kill outright, causing caterpillars to vomit green and if it was strong enough, they die. Some of the medications cause improper pupation. Even others cause their mouth parts to work improperly, causing them to fail to eat well and they become weak and don’t grow normal.

You can learn more about the effects of flea/tick medication by clicking on this sentence.

Although chrysalises may be deformed due to other causes, flea/tick medication is one of the common causes for this problem.

If you are raising butterflies at home, there are are several facebook groups that has tips. Everyone shares what works best for them.

Facebook: Caterpillar to Butterfly

We also share tips (and special offers) on Butterfly Conservation Supplies.

Which do you like better?  White or black mesh?  You can see through black mesh better than white mesh.

What should I plant for swallowtails?  This often-asked question is often answered with, “Fennel, dill, and parsley”.  But there are other species of swallowtails and most use different plants.

Note: not all species are found in every state.  Planting a host plant for a species that does not fly in your state will not make them appear and lay eggs.  We should all plant host plants for species that are found in our area.

(These are only some of the plants that these species use as host plants.  There are many others that we did not list.)

Spicebush Swallowtail and Palamedes Swallowtail:

Red Bay Persea borbonia
Swamp Bay Persea humilis
Silk Bay Persea palustris
Sassafrass Sassafras albidum
Spicebush Lindera benzion
Camphor tree (invasive non-native) Cinnamomum camphora

Zebra Swallowtail:

Pawpaw Asimina spp.

Gold Rim Swallowtail (also called Polydamas Swallowtail):

Important note: Buy pipevine plants according to their botanical names, not their common names.  Many species of pipevine have the same common name. Some pipevine species are deadly to Gold Rim Swallowtail caterpillars.

(Click on this sentence for a more complete list.)

Dutchman’s Pipe – Aristolochia trilobata
White-veined Pipevine – Aristolochia fimbriata
Fragrant Dutchman’s Pipe – Aristolochia pandurata synonym of Aristolochia odoratissima
Brazilian Dutchman’s Pipe or Giant Pelican Flower – Aristolochia gigantea
Calico Vine – Aristolochia littoralis (was A. elegans)
Dutchman’s Pipe – Aristolochia trilobata
Fragrant Dutchman’s Pipe – Aristolochia pandurata (was Aristolochia odoratissima)
Indian Birthwort – Aristolochia tagala

Pipevine Swallowtail:

Important note: Buy pipevine plants according to their botanical names, not their common names.  Many species of pipevine have the same common name. Some pipevine species are deadly to Pipevine Swallowtail caterpillars.

(Click on this sentence for a more complete list.)

Dutchman’s Pipe – Aristolochia trilobata
White-veined Pipevine – Aristolochia fimbriata
Fragrant Dutchman’s Pipe – Aristolochia pandurata synonym of Aristolochia odoratissima
Dutchman’s Pipe – Aristolochia macrophylla
Dutchman’s Pipe – Aristolochia trilobata
Fragrant Dutchman’s Pipe – Aristolochia pandurata (was Aristolochia odoratissima)
Virginia Snakeroot – Aristolochia serpentaria
White-veined Pipevine – Aristolochia fimbriata
Woolly Pipevine – Aristolochia tomentosa
Birthwort – Aristolochia clematitis

Eastern Tiger Swallowtail:

Tulip Poplar Liriodendron tulipifera
Hop Tree Ptelea trifoliata
Black Cherry Prunus serotina
Sweet Bay Magnolia virginiana

Giant Swallowtail:

Citrus trees Citrus spp.
Hop Tree Ptelea trifoliata
Rue Ruta graveolens
Prickly Ash Zanthoxylum americanumn
Hercules’ Club Zanthoxymum clava-herculis

Black Swallowtail and Anise Swallowtail:

(Click on this sentence for a more complete list.)

Parsley Petroselinum spp. 
Fennel Foeniculum vulgare
Dill Anethum graveolens
Queen Annes’ Lace Daucus Carota
Carrots Daucus carota
Rue Ruta graveolens

Canadian Tiger Swallowtail

Aspen Populus spp.
Black Cherry Prunus serotina
Birch Betula spp.

Ornythion Swallowtail – Papilio ornythion

Citrus trees Citrus spp.

Appalachian Tiger Swallowtail – Papilio appalachinensis

Black Cherry Prunus serotina

Western Tiger Swallowtail – Papilio rutulus

Willows Salix spp.
Wild Cherry Prunus spp.
Ash Fraxinus spp.
Aspen Populus spp.

Old World Swallowtail – Papilio machaon

Sagebrush Artemisia spp.
Wild Tarragon Artemisia dracunculus
Arctic Wormwood Artemisia senjavinensis

Indra Swallowtail – Papilio indra

Herbs in the parsley family Apiaceae spp.

Pale Swallowtail – Papilio eurymedon

Cherry Prunus emarginata
Ash Fraxinus spp.
Coffee-berry Rhamnus californica

Two-tailed Swallowtail – Papilio multicaudata

Chokecherry Prunus spp.
Hop Tree Ptelea spp.
Ash Fraxinus spp.

How does a chrysalis hold on to the silk pad so tightly?  This greatly magnified view tells the story. Tiny hooks at the tip of the cremaster (the black ‘stem’ on a Monarch chrysalis) tangle tightly into the silk pad.  The twisting dance that a chrysalis does when it is through pupating is to work these tiny hooks into as many of the silk loops as possible.

A Monarch chrysalis cremaster is so tiny that we can’t see the tiny hooks that hold the chrysalis to its silk button.  These are scanning electron microscope images, taken of some of our Monarch chrysalises, by Illustra Media.

Shady Oak Butterfly Farm shipped empty chrysalis shells to Lad Allen in California for their movie, ‘Metamorphosis’.