California Gardens - The Year Round Gardening Site

Monarch Butterfly - Danaus plexippus

The Monarch Butterfly is probably the best recognized butterfly around. People often plant Tropical Milkweed Asclepias curassavica, to encourage the Monarch Butterflies to lay their eggs (see the single monarch egg below) in their yards. The Monarch eggs can often be found on the undersides of the milkweed leaves. The eggs are laid one at a time. Monarch cocoons can be purchased to get your population started. The Monarch caterpillar feeding on the Butterfly Weed, Asclepias tuberosa will gradually eat all of the leaves from the plants before making its cocoon (see below). The Monarch Butterflies will often migrate back to where they left their cocoons. So you can often get the Monarch Butterfly to come back to your butterfly garden and lay another season's eggs year after year. Adult Monarchs will feed on goldenrod (Solidago), a number of salvias, Mustang Mint (Monardella), Plumeria, and a wide variety of plants in the manzanita family. The adult Monarchs also love the nectar of Verbena bonariensis, Verbena lilacina De La Mina, Verbena lilacina Paseo Rancho, and Verbena rigida. The migrations of the Monarch Butterfly's are legendary. Many of the Monarch Butterflies winter in Mexico and make their way to most parts of North America. Some populations over-winter here in Southern California. There are a number of eucalyptus groves that can become draped in butterflies during their stay here in Southern California. The Monarch Butterfly in the third image is sipping the nectar of the California native, Narrowleaf Milkweed, Asclepias fascicularis. The milkweed has a toxin that gets incorporated into the bodies of the Monarch Butterflies and makes them taste bad to some of their predators. There are a number of other butterflies that have similar enough coloring and markings so that birds remember their prior bad experience with a Monarch and they get protection too. Monarch Migration is beyond amazing, reaching from the mountains of Mexico well into Canada. Monarch Butterflies will fly north in the Spring, each generation flying a few weeks until they run out of energy. On their last gasp of life the females lay their eggs. Somehow the resulting caterpillars know what to do. In the Spring they fly on. Somehow during the Summer months they figure they need start flying south again, each leg of their journey takes multiple generations. Some Monarch Butterflies never migrate at all. It is not known exactly what cues their migrating behavior. Any link in this process that breaks can break the Monarch's magical existance. News of illegal logging in Mexico is linked to a Butterfly Decline. As is the removal of trees they cluster in to keep warm in the winter, or a drought that limits the milkweeds that they need to create the next generation to continue their journey.

Monarch Butterfly Egg

Egg from a Monarch Butterfly - Danaus plexippus. High resolution photos are part of our garden image collection.

Monarch Butterfly Egg

Egg from a Monarch Butterfly - Danaus plexippus. High resolution photos are part of our garden image collection.

1st instar Monarch Caterpillar

1st instar Monarch Butterfly Caterpillar, note the black head, 1st instar caterpillars are the only stage with a black head. The head is the same size as the egg that it emerged from.

Monarch Caterpillars

2nd and 3rd instar Monarch Butterfly Caterpillars feeding on tropical milkweed leaves. The antennae are the only true tell, the size is too variable to determine which instar should be used to describe them. Interestingly the yellow caterpillar has maintained its distinctly paler coloring all the way to 5th instar.

4th Instar Monarch Caterpillar, Asclepias tuberosa

A 4th instar Monarch Butterfly Caterpillar feeding on Asclepias tuberosa, Butterfly Weed. The antennae are the only true tell, the size is too variable to determine which instar should be used to describe them. 5th instar antennae can reach down to the leaf.

Monarch Caterpillar on Milkweed

A 5th instar Monarch Butterfly Caterpillar is feeding on tropical milkweed. To keep tropical milkweeds from harming Monarch Butterflies it is recommended that you trim the foliage down to an inch or two above the ground during the winter months. I often do this twice and cut the plants nearly to the ground. The tropical milkweeds almost always recover from this abuse.

Monarch Caterpillar Anatomy Labeled

A 4th instar Monarch Butterfly Caterpillar has its anatomy labeled. Tentacles are sensory tools and very active. A spiracle is a breathing organ connected to trachea that spread oxygen throughout the body. Ocelli are rudimentary eyes, there are 6 pairs. The mandible is the mouth. Antenna are sensory organs. And the spinnaret makes silk. Caterpillars often attach themselves to a leaf or branch as they fall, then climb back up the silk. When ready to make their chrysalis they use the silk to attach it to something, often a leaf or branch.

Adult Monarch Butterfly on Milkweed

Adult Monarch Butterfly feeding on the native Narrow Leaf Milkweed. Native Milkweeds do not present a problem for the Monarch Butterflies regarding Protozoans as the plants naturally go dormant. The protozoans are a native pest on a native species but they can build up concentrations on tropical milkweeds that can cause problems for the butterflies if the foliage is not periodically removed. The Monarch Butterfly wings get clogged with the tiny organisms and fail to open properly. TheTropical Milkweeds recover quickly from even the most vigorous trim job. Almost everybody knows that insects have 6 legs. But look closely the Monarch Butterflies only have 4. Check around the internet you will almost never see more than 4 legs on a Monarch. The two front legs are held against their body most of the time. They sometimes reach out and touch/smell something with them. They have a sensory ability to do that with their "Brush Feet"

Tachinid from Monarch

One of the greatest challenges facing the Monarch Butterflies is parasitic fly called a Tachinid. This fly hatched from its pupa after a exiting from its Monarch Host just a few hours before this photo was taken. While I believe in the idea that we should let nature take its course this fly was not released.

Monarch Tachinid Striken

This injured Monarch Butterfly went from its normally vibrant colors to looking like this dark menace over the course of a day while I was at work. The Monarch hung like this for a couple more days before disappearing. It is likely that this monarch caterpillar had been parasitized by a Tachinid Fly. The droppings changed from their normal black dots to these translucent volcanos.

Tachinid pupa

Tachinid flies parasitize Monarch Butterflies by laying their eggs on Caterpillars, and Chrysalis' while they are still soft or Adult Monarch Butterflies. The eggs hatch and the maggots eat the Monarch Butterflies from the inside out. When they emerge from their Monarch host they parachute down on silk threads. These Tachinid Flies just hatched from their pupa 12 days after leaving their Monarch Host. There is still one left to emerge.

J shape Monarch caterpillar

After 5 instars the Monarch Caterpillar hangs in a J shape as it prepares to form the Chrysalis within which it will turn into a Butterfly.

Fresh Monarch Chrysalis

A freshly formed Monarch Chrysalis, you can faintly see the Monarch Butterfly inside.

Monarch Emergent Chrysalis

An almost  Emergent Monarch Chrysalis that is so close to popping you can see the Monarch Butterfly inside. This is what happens when everything goes right. The Monarch Caterpillar attached its chrysalis to a nearby Penstemon bush.

Asclepias curassavica, Tropical Milkweed, Monarch and Caterpillar

Adult Monarch Butterfly and Monarch Caterpillar feeding on Tropical Milkweed.

Monarch House

Monarch Caterpillars feeding on Narrow Leaf Milkweed in a Monarch House protecting them from Tachinid Flies and Wasps.

I got to see the most amazing Monarch farming operation recently. A client is farming monarch caterpillars to great success. She bought herself a bunch of milkweed plants of varying species. Each day she searches her plants for eggs and clips off the portions of the leaf with an egg and brings all of the eggs indoors and puts them leaf and all on a damp paper towel in a baking dish covered with saran wrap to keep out the flies. When the caterpillars mature enough, usually by the 3rd instar, she puts them outside on plants that she has put into a monarch house. A 2 x 2 x 3 foot screened in box with a zippered door and one clear side. The Monarch house keeps out the parasitic tachinid flies and is big enough to house a live plant or two. She lays the caterpillars on their leaves at the base of the sheltered plant and they climb up and eat away. She started her farm a little more than a month ago and has released well north of 100 adult monarchs. 7 monarchs were released while I was working there. I was sent home with two houses and about 50 eggs and caterpillars of various ages to start a farm of my own. I sized up a bunch of my milkweed plants to encourage them to grow faster a few weeks ago. Adding the additional room for the roots worked but I am not sure the milkweeds will grow and regrow fast enough to keep up with all of my hungry dinner guests. The Monarch population has chrashed and is at less than one percent of its historical levels. There are wonderful ways to help these beloved butterflies with citizen science by connecting with the Xerces Society

Monarch Farm

Monarch Eggs and Caterpillars collected and fed through their early instars in a baking dish protecting them from tachinid flies.

Monarch House Chrysalis

Monarch chrysalis' hanging in a monarch house to protect them from tachinid flies. Note that some are green and others black. Once the Chrysalis turns black the Monarch Butterfly is close to emerging. Once the butterfly emerges it leaves the transparant chrysalis behind.

Monarch House Butterfly

A Monarch Butterfly is just pumping up its wings after emerging from its chrysalis less than an hour prior to the photo. The Monarch Butterflies are being kept in a monarch house to protect the from predators, but primarily to protect them from tachinid flies prior to their release. I put in a link for the butterfly house used on this Monarch Butterfly farm. Profits from these Amazon links support our site. Thanks for your support.

Monarch Caterpillar Feeding

A swarm of Monarch Butterfly Caterpillars feeding on Narrow Leaf Milkweed, Asclepias fascicularis. I had propagated a lot of plants but they were in small pots, to amplify the foliage I sized the milkweeds into larger pots. I am sure it won't surprise you looking at this photo that the caterpillars will finish off the leaves from this plant in less than a day. Thankfully I was prepared with a lot of food for my dinner guests.

Monarch Caterpillar Feeding Brick

A feeding brick for the Monarch Butterfly Caterpillars, they are feeding on Bladder Vine, Araujia sercifera. An early test was to see if the Milkweed related Bladder Vine was acceptable food for the Caterpillars. They were slow to think that this would be OK until the Narrow Leaf Milkweed plant started to get pretty bare. Then at every instar level they ate the Bladder Vine with the same enthusiasm as the Tropical Milkweed plants I stuck in next. I have started propagating both the Bladder Vine and the Tropical Milkweeds from the striped bare stems that the caterpillars left me. The brick was meant to hold down the Butterfly house at first but then with the aid of a masonry bit the brick became a vase holder for the milkweed leaves and stems of plants from the garden.

Monarch Release

A male Monarch Butterfly is about to be released. Note the dark spots on the hind wing. These spots are glands that are unique to male Monarch Butterflies. The glands secrete pheromones (a fancy word for perfume) into the atmosphere that attracts female Monarch Butterflies.

Female Monarch Butterfly Laying Egg

A female Monarch Butterfly is about to lay an egg. Note the dark spots on the hind wing of the previous butterfy image. These spots are glands that are unique to male Monarch Butterflies. The glands secrete pheromones (a fancy word for perfume) into the atmosphere that attracts female Monarch Butterflies.

Monarch Wing Scales

The beautiful paterns and colors of a Monarch Butterfly come from hairs and scales on the wings and body of the butterfly.

Monarch Roost

Between November and January Monarch Butterfies migrate to protected locations along the Coast of California and the Mountains of Mexico where they roost . They hang in large clusters like this one in Elwood Preserve near Santa Barbara. They shiver to keep each other warm.

A Video that follow the life cycle of Monarch Butterflies from laying eggs to forming their chrysalis.

A video of a Monarch Caterpillar, followed by an Adult laying eggs on Asclepias fascicularis the Narrowleaf Milkweed. More information on growing the Narrowleaf Milkweed in your garden can be found by following the link. High resolution photos of this plant are part of our garden image collection.

Plants for Monarch Butterflies
Araujia sericifera * Bladder Vine, Cruel Vine, Moth Vine
Arbutus Marina * Marina Strawberry Tree
Arbutus unedo * Strawberry Tree
Arctostaphylos edmundsii Danville * Danville Manzanita
Arctostaphylos edmundsii Little Sur * Little Sur Manzanita
Arctostaphylos Howard McMinn * Vine Hill Manzanita
Arctostaphylos insularis * Island Manzanita
Arctostaphylos John Dourley * John Dourley Manzanita
Arctostaphylos Lester Rowntree * Lester Rowntree Manzanita
Arctostaphylos Pacific Mist * Pacific Mist Manzanita
Asclepias californica * California Milkweed
Asclepias cordifolia * Purple Milkweed
Asclepias curassavica * Tropical Milkweed, Bloodweed
Asclepias curassavica Silky Gold * Silky Gold Tropical Milkweed
Asclepias eriocarpa * Woolypod Milkweed, Indian Milkweed, Kotolo Milkweed
Asclepias erosa * Desert Milkweed
Asclepias fascicularis * Narrow Leaf Milkweed, Mexican Worled Milkweed
Asclepias linaria * Pineneedle Milkweed
Asclepias speciosa * Showy Milkweed
Asclepias tuberosa * Butterfly Weed
Bacharis pilularis * Coyote Brush
Berberis nevinii * Nevin's Barberry
Berberis thunbergii atropurpurea * Japanese Barberry
Ceanothus Centennial * Centennial California Lilac
Ceanothus burtonensis Far Horizons * Far Horizons California Lilac
Ceanothus Concha * Concha California Lilac
Ceanothus crassifolius * Hoary California Lilac
Ceanothus Dark Star * Dark Star California Lilac
Ceanothus Frosty Dawn * Frosty Dawn California Lilac
Ceanothus gloriosus Anchor Bay * Anchor Bay California Lilac
Ceanothus greggii * Desert Ceanothus
Ceanothus hearstiorum * Hearst's California Lilac
Ceanothus Joan Mirov * Joan Mirov California Lilac
Ceanothus Joyce Coulter * Joyce Coulter California Lilac
Ceanothus megacarpus * Bigpod California Lilac
Ceanothus oliganthus soriedatus Jim Brush, Hairy Ceanothus
Ceanothus Point Sierra * Point Sierra California Lilac
Ceanothus Ray Hartman * Ray Hartman California Lilac
Ceanothus Snow Flurry * Snow Flurry California Lilac
Ceanothus Tassajara Blue * Tassajara Blue California Lilac
Ceanothus Valley Violet * Valley Violet California Lilac
Ceanothus Wheeler Canyon * Wheeler Canyon California Lilac
Ceanothus Yankee Point * Yankee Point California Lilac
Chilopsis linearis * Desert Willow
Chilopsis Purple Splendor Purple Splendor Desert Willow
Chrysothamnus nauseosus * Rabbit Brush
Cirsium occidentale * Cobwebby Thistle
Encelia californica * California Brittle Bush, Coast Sunflower
Encelia farinosa * Brittle Bush
Encelia Paleo Yellow * Paleo Yellow Brittle Bush
Encelia ventorum * Baja Bush Sunflower
Ericameria nauseosa * Rabbit Brush
Erigeron argentatus * Silver Fleabane
Erigeron Bountiful * Bountiful Seaside Daisy
Erigeron karvinskianus Santa Barbara Daisy, Mexican Daisy
Erigeron Sea Breeze * Sea Breeze Seaside Daisy
Erigeron speciosa * Aspen Fleabane, Showy Fleabane, Oregon Fleabane
Erigeron Wayne Roderick * Wayne Roderick Seaside Daisy
Eriodictyon crassifolium * Felt Leaved Yerba Santa
Eriodictyon tomentosum * Woolly Yerba Santa
Mahonia nivinii * Nevin's Barberry
Malosma laurina * Laural Sumac
Monardella lanceolata * Mustang Mint
Monardella odoratissima * Mountain Monardella, Desert Mint
Prunus andersonii * Desert Peach
Prunus campanulata * Taiwan Flowering Cherry
Prunus ilicifolia * Holly Leaf Cherry
Prunus ilicifolia lyonii * Catalina Cherry
Rhus integrifolia * Lemonade Berry
Rhus ovata * Sugar Bush
Ribes aureum * Golden Currant
Ribes malvaceum * Chapparal Currant
Ribes malvaceum viridifolia Ortega Beauty * Ortega Beauty Currant
Ribes speciosum * Fuchsia Flowered Currant
Salvia Allen Chickering * Allen Chickering Sage
Salvia apiana * White Sage
Salvia brandegeei * Brandegee's Sage, Santa Rosa Island Sage
Salvia carduacea * Thistle Sage
Salvia clevelandii * Cleveland Sage
Salvia Desperado * Desperado Sage
Salvia dorrii dorrii * Purple Desert Sage
Salvia leucophylla Amethyst Bluff * Amethyst Bluff Purple Sage
Salvia leucophylla Bee's Bliss * Bee's Bliss Sage
Salvia leucophylla Point Sal Spreader * Point Sal Spreader Purple Sage
Salvia mellifera * Black Sage
Salvia mellifera Green Carpet * Green Carpet Creeping Sage
Salvia mellifera Skylark * Skylark Sage
Salvia mellifera Terra Seca * Dwarf Black Sage
Salvia munzii * San Diego Sage, Munz's Sage
Salvia munzii Emerald Cascade * San Miguel Mountain Sage, Munz's Sage
Salvia Winnifred Gilman * Winnifred Gilman Sage
Sidalcea malvaeflora * Checker
Spharalcea ambigua * Desert Mallow
Spharalcea ambigua rosacea * Rosy Apricot Mallow, Apricot Globemallow
Spharalcea fulva La Luna La Luna Globe Mallow
Spharalcea philippiana * Trailing Globemallow
Tithonia rotundifolia * Mexican Sunflower
Trichostema lanatum * Woolly Blue Curls
Trichostema lanceolatum * Vinegar Weed
Trichostema Midnight Magic * Midnight Magic Blue Curls
Verbascum chaixii album * Nettle Leaved Mullein
Verbascum Southern Charm * Southern Charm Mullein
Verbena bonariensis * Purpletop Vervain
Verbena lilacina De La Mina * Cedros Island Verbena
Verbena lilacina Paseo Rancho * Paseo Rancho Verbena
Verbena rigida * Sandpaper Verbena