Monarch Caterpillars Have Supersized Appetites, Eat 200X their Weight in Milkweed Leaves

Returning from a weekend on the Llano River to find dozens of Monarch butterfly eggs on my just-planted milkweed made my Sunday evening.   Especially after finding no milkweed in the wild or along the river banks.  I fear the brutal freezes and rainless spring have us in a Monarch butterfly food shortage.

The good news is several of my eggs have already hatched.  I’ll bring some of them along to the Land Heritage Institute this Saturday in San Antonio at 12:30 PM if you’d like to see them at the San Antonio Native Festival. I’ll be among several panelists talking about native plants and critters–Monarchs and Swallowtail butterflies, specifically.

You may think concerns are exaggerated regarding satisfying Monarch butterflies’ appetites but take a look at the video and realize that Monarch caterpillars–like all lepidoptera–have a voracious hunger, gorging on 200X their birthweight in milkweed leaves in a brief 10 – 14 days.   Imagine a seven-pound newborn child consuming 1400 pounds of formula in a two-week period.

Commercial butterfly breeders tell me that each Monarch caterpillar can easily defoliate an entire one-gallon milkweed plant–consuming 175 – 200 leaves per caterpillar–before eclosing to the chrysalis stage.

Of course, it depends on the milkweed you supply.  ”If you’re feeding wild milkweed in Texas the leaves are meatier and larger than tropical milkweed,” says Linda Rogers of the Butterfly Boutique, a butterfly farming operation in Corsicana, Texas.

No doubt our native Texas milkweed, Antelope Horns, Asclepias asperula, is much heftier than the Tropical Milkweed, Asclepias curassavica, found in nurseries right now–like beef steak compared to lettuce.  While we would prefer to serve our Monarch visitors only native Texas milkweed, when there’s none available we’ll take what we can get.

For more on milkweed, check out the Texas Butterfly Ranch Milkweed Guide.

3 thoughts on “Monarch Caterpillars Have Supersized Appetites, Eat 200X their Weight in Milkweed Leaves

  1. nice munching audio effects on the video — Monarchs need milkweeds immediately! (but also thinking longterm… now is the time to plant milkweeds from seed for future caterpillars. Native American Seed has native milkweed seeds available)

  2. Pingback: Butterfly FAQ: Is it OK to Move a Monarch Chrysalis to a Safer Location? Yes, and Here’s some Tips to Keep in Mind | Butterfly Beat | a mySA.com blog

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