Why Does Roadside Butterfly Habitat Matter?

Monarch butterfly numbers have taken a nosedive.  There were reports about this all summer, and a recent report over at the Texas Butterfly Ranch blog.


The caterpillar host plants of monarchs are milkweeds of various species.  With the herbicide resistant crops, the milkweeds that were once common in the rows between crops are gone.  I suspect we are mainly talking about common milkweed, Asclepias syriaca, and possibly blunt-leaved milkweed,  A. amplexicaulis.  Whorled milkweed, A. verticillata was probably also present in some numbers, but I have my doubts about it as a host plant for monarchs.

Common milkweed is still present in the ditches around Iowa, and is easy to find.   But the total number of plants has to be way down.  How much area is in the thirty foot line around the perimeter of the field, compared to the area of the field?

Monarch habitat may be easier to maintain than habitat for more stationary butterflies.  If you do something to the habitat in the winter–mow too closely, burn, or something similar, you might eliminate other species altogether.  Monarchs repopulate each year from populations that overwinter in the south, and might survive habitat modifications that wipe out others.

About the roused bear

Nature photographer from central Iowa.
This entry was posted in Biological diversity, butterflies, monarch, Uncategorized and tagged , , , , , . Bookmark the permalink.

1 Response to Why Does Roadside Butterfly Habitat Matter?

  1. Pingback: Great Spangled Fritillary | Winged Beauty

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s