Caterpillars: The Important Part

Let’s face facts.  Caterpillars are Butterflies in the making.  Or Moths.  But let’s focus on the Butterflies.  Butterflies lay eggs onto plants that the Caterpillars (aka Baby Butterflies) like to eat. Caterpillars hatch, feast relentlessly and then metamorphose into their adult Butterfly form.  Therefore, Caterpillars are the important part - a vital stage in the life cycle.  So, how do we protect them?

We must plant the plants that caterpillars like to eat.  

Create an area, or two, of your garden that is like a Maternity Ward for the caterpillars.  Please understand that these areas may sacrifice beauty to continue the Butterfly life cycle.  If everything goes well, the caterpillars will strip the plants bare while prepping for their next stage.  

What plants do Caterpillars like?  Well, that depends on the Caterpillar.  There is a wonderful book by Rita Venable called Butterflies of Tennessee that has all the info on this subject.  Rita studied these Caterpillars and Butterflies and has listed their favorite food sources.  Here are a few that I grow plants for in my garden.

1. Eastern Tiger Swallowtail – Tulip Poplar (Liriodendron)

2. Black Swallowtail – Parsley, Dill, Fennel

3. Monarch – Butterfly Weed, Milk Weed (Asclepias)

4. Spicebush Swallowtail – Spicebush (Lindera benzoin)

5. Zebra Swallowtail – Paw Paw Tree (Asmina triloba)

There are many other host plants for Caterpillars.  One of the best is Oak trees (Quercus).  In the book, The Nature of Oaks, by Dr. Doug Tallamy, we learn that oak trees are host plant to around 33 different Caterpillars.  Dr. Tallamy focuses on how the Oak trees and those Caterpillars feed the bird population, rather than beautiful Butterflies.  But hey, being a food source for another level of the food chain is important too.

We should limit use of chemicals (even organic ones) in the garden.  

For this section, I will try to stay off my soap box.  It has been quite a while since I was in Integrated Pest Management in college but here we go.  Insecticides work in a few ways; they destroy the nervous system or stop the insect from being able to feed. There are probably others but these are the most popular.  Sounds terrible, right?  If it was people and not bugs, we would be totally against it.  Insecticides are usually not very targeted either. Most of them kill most things. There is even one that does target Caterpillars.  But not just the ones we don’t like (ieTomato Horn Worm, Bag Worms), it kills all of them.  It is called Bt and it is a naturally occurring fungus that can rupture the organs in Caterpillars.  It is very effective but also non-discriminatory.

What would I rather have you do?  Practice 15 foot gardening.  If you notice insects on a plant in your garden, step back 15 feet.  Can you still see the insects? The damage? Not really? Perfect, then let the ecosystem take care of it.  OR Yes, too much!  Okay, then lets try manual removal before chemicals.  No, I don’t mean pick every insect off.  Just give the plant a hair cut.  Prune out as much of the infestation as you can.  Do not compost these clippings. Bag them up and get them off the property.  If this plant continues to become infested, then consider removal and replacing with something else.

Listen, I can’t stop you from using chemicals.  I am just begging you to use less or none.  Here is another reading recommendation. The Insect Crisis by Oliver Milman.  

And, please remember that not every “infestation” is a bad thing.  Butterflies and Moths are great pollinators.  They are very helpful and pretty for the environment.

I digress.  

I would be happy to talk to you more about this.  Let’s open a conversation in the comments or at the Garden Center.