Host an Event Volunteer Join Tickets

Support the plant database you love!

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
Not Yet Rated

Saturday - January 23, 2016

From: Winchendon, MA
Region: Northeast
Topic: Pests, Herbs/Forbs, Wildflowers
Title: Caterpillars on Milkweed in MA
Answered by: Anne Van Nest

QUESTION:

I have found every year a black/red caterpillars on my milkweed. They eat everything! I have never been able to find out what they are or how to get rid of them.

ANSWER:

The milkweed tussock caterpillar (Euchaetes egle) is a common summertime feeder on milkweeds (Asclepias spp.) and dogbane (Apocynum spp.) in a huge area from southern Canada to Texas. Wikipedia says that the older caterpillars are gregarious and sport tufts of black, white and orange hairs with a black head. This coloration mimics the monarch butterfly caterpillar in a hope to ward off predators. The adult butterfly is a gray and yellow with rows of black dots on the dorsum.

Willow House Chronicles has a blog post about your caterpillar. Barefootheart says: The Tussock moth label is a misnomer, as these moths are classified with tiger moths. Another tiger moth caterpillar that you are probably familiar with is the Woolly Bear.

Some people have an allergic reaction, developing a rash, after handling these caterpillars, so it is not a good idea to pick them up, no matter how cute and fuzzy them may look.

Female moths lay large batches of eggs, and while the caterpillars are tiny, they live together on one plant before dispersing. Monarch butterflies are well know to also use milkweed as their larval food source, but Wagner notes that Monarchs tend to prefer young shoots, while Tussocks are content to eat older foliage. The caterpillar will overwinter in a cocoon and emerge as a moth next year.

 

These caterpillars will most likely be an annual visitor to your milkweeds and a sustainable strategy should be to encourage more milkweeds fluorish so that there is plenty of host plants for you and your visiting insects.

 

From the Image Gallery


Swamp milkweed
Asclepias incarnata ssp. pulchra

Common milkweed
Asclepias syriaca

Common milkweed
Asclepias syriaca

Common milkweed
Asclepias syriaca

Butterflyweed
Asclepias tuberosa

Butterflyweed
Asclepias tuberosa

Butterflyweed
Asclepias tuberosa

Red milkweed
Asclepias rubra

Zizotes milkweed
Asclepias oenotheroides

More Wildflowers Questions

A&M maroon bluebonnets for Hawaii
July 10, 2011 - My daughter graduated from Texas A&M and has moved to Hawaii. She would love to have the maroon bluebonnets developed by A&M to plant in her new home. How would she need to prepare the seeds since t...
view the full question and answer

More on bluebonnets
January 09, 2007 - I have had an area in my yard where I have established bluebonnets. Since we had such a dismal showing in the spring of 2006 I was looking forward to a great show for 2007. Lo and behold I had about...
view the full question and answer

Yellow Indian paintbrush, Castilleja indivisa
May 09, 2005 - Does entireleaf Indian paintbrush, Castilleja indivisa, come in yellow in the wild? I have Indian paintbrush in the front pasture and noticed last weekend that there were 5 or 6 that were light yellow...
view the full question and answer

Wildflower gardening for Citrus Co., Florida
March 07, 2008 - I live in Citrus County Florida, on the north central, west side of the state. I hope to start a wildflower meadow in my natural back yard. Can you recommend good wildflowers to grow, and where to g...
view the full question and answer

Hymenocallis caroliniana and Hymenocallis liriosme Differences
October 09, 2013 - A couple of years ago a neighbor gave me three huge bulbs of a type unknown to her. They fit the description of a spider lily. In attempts to identify it I found Hymenocallis liriosme and Hymenocallis...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.