Sunday, March 6, 2011

Chestnut-marked Pondweed Moth

Chestnut-marked Pondweed Moth Parapoynx badiusalis
A long name for something so small.  Its wingspan is only about 20 mm.  But fairly common at certain times in the summer at Westwood (if you choose to look).  I've seen these moths for years, but only last summer took the time to try to ID.

The caterpillars of this moth are aquatic.  They eat pondweed (not seaweed, as I hear most kids refer to green stuff in the pond),specifically members of the genus Potamogetan.

Potamogetans are commonly known as pondweeds, but not all plants we generally call "pondweed" are Potamogetans.  At Westwood the kind of pondweed growing in the lake is called Sago Pondweed, P. pectinatus.

Something we don't notice eating something else we don't notice.

But actually Sago Pondweed is more than some green stuff floating in the water, or a little moth caterpillar's lunch, it's extremely important to waterfowl.  All parts of the plant are eaten by various waterfowl.  It's so important, that the migration pathways of some ducks follow large bodies of water that contain plentiful Sago Pondweed.  Click here more information about Sago Pondweed.

There are a number of different Potamogeton species in MN.  One of them, the Curly-leaf Pondweed is an invasive.  As I was reading about pondweeds I found a very unhelpful picture.  My sketched version is to the right.  I wonder if the Chestnut-marked Pondweed moth eats this nonnative Potamogeton?

Below are two more sketches,

Sago Pndweed

Chestnut-marked Pondweed Moth