Thursday, July 23, 2009

Genista Caterpillars & Scotch Broom Plant

Genista caterpillar (Uresiphita reversalis) Pyralid Moth feeding on Scotch Broom

While trimming vines and bushes the other day in the yard, the kids noticed that one of the bushes was covered with caterpillars!

We weren't sure what type of caterpillars they were, so we found out the type of plant...Scotch broom. It grows wild throughout California, and it's a plant that we've used for dyeing. Then, we did some research to find out what caterpillars like to eat broom and ended up learning about the genista caterpillar.

Some websites claim that the genista is a "pest" and can defoliate complete bushes and trees in some parts of the US. After observing the caterpillars for a week, we realized that to us, they are not a pest, and although they have been hungrily munching away at the leaves, the bush still has a lot of leaves.

Now, the caterpillars are moving slowly and they have made some interesting-looking webs. We will continue to watch them, hoping to catch the final phase when they become moths! A wonderful person on who had pictures of genista told us that the moths will come out of the cocoons at night.

We decided to wait and trim the bush once the caterpillars have become moths. Then, we will take the timmed branches and dye with them, as broom makes a lovely green-yellow color for our handspun yarns!


Jen said...

Very interesting post and sweet of you guys to let them stay and develop. We've been learning and playing with butterflies/moths, too! Am finishing up a post to wrap up soon. 'Tis the season - LOL! Happy hatching!

Jill said...

Your post on scotch broom makes me think of the big bushes outside our home in Carmichael where I grew up. We loved touching it as we walked down to the river, and I have missed it here on the East Coast. I was not aware that you could dye with it. I will have to remember that when I come back for a visit.

Anonymous said...

Interesting post!
We have been captivated by moths we have found throughout the summer.
It is amazing how many living things we may not know much about until experiencing them in nature.
It is certainly wonderful to be learning at home alongside the kids! I just noticed all of your blogs, you are an unbelievably talented family! I appreciate your recent comment on my post, I found it very interesting to hear what you have studied!

Angela said...

Interesting - i have always been told that scotch broom is an invasive here, esp in disturbed areas (as in, where logging takes place). interesting to know something likes to eat it.

i think it's just wonderful that instead of acting immediately (ack, caterpillars!), you sat back, observed, and made it a learning experience for the family. very cool.

also, i never knew it could be used for dying fiber. Thanks for the informative post!

June said...

How wonderful to participate in the natural order of things rather than to intrude and interrupt.

Happy to have found you. We are home-learners too and our meadow is full of milkweed we preserve for the monarchs.

Lisa said...

LOL! Love flower meadow, it started playing and I perked up thinking I heard a new type of bird out our windows!

Love this post. I love learning about new caterpillars. They can be so hard to identify......

Lisa :)

Rena Nelson said...

We have a beautiful scotch-broom in our yard until we noticed it appeared to be dying. When we observed it closer we saw that there were hundreds of caterpillars that had eaten every single leaf. They made their cocoons everywhere (very sticky) after they turned into moths the tree was coming back, unfortunately there is yet another round of caterpillars on the bare stems and the bush is quickly dying. I've heard of a product called BT (for short)that should work and is bio-friendly. I hope it survives.