What's in a name: Eyed Brown Butterfly (Lethe Eurydice or Satyrodes eurydice)

Yesterday, I didn't get a species post up, but I did log one. It was the eyed brown butterfly (Lethe eurydice or Satyrodes eurydice). When I told my wife that name, the first thing she asked was "Shouldn't it be the brown-eyed butterfly?"

The answer is no. The butterfly in question, is brown and has eyespots. It does not have brown eyes. In bird and insect naming convention, when an adjective, like a color, applies to a specific feature, the accepted practice is to use a hyphen to link them. For example, the two-spotted bumblebee, the green-striped grasshopper, and so forth. In the first case, the bumblebee has two spots, and in the second, you guessed it, the grasshopper has green stripes.

Now what if the grasshopper was green and had stripes of a different color? Then it might be the striped green grasshopper, or possibly the green striped grasshopper, without a hyphen although the latter option would be a little more confusing and, for that reason, less likely to be used.

The eyed brown butterfly (Lethe eurydice)
Photo by Brad Sylvester, copyright 2011, all rights reserved

So, the  Lethe eurydice or eyed brown butterfly, follows this convention and is named for the prominent eye spots on its wings, making it Eyed, and is predominantly brown in color, making it the Eyed Brown Butterfly.

See a slideshow of the Eyed Brown Butterfly, here.

The eyed brown butterfly, by the way, unlike the monarch butterfly which flies great distances as it migrates, is a relatively poor flyer, and it doesn't migrate at all. Instead, the larva or caterpillar version emerges from the egg and puts on size and weight through the summer and fall, and waits, dormant, through the winter before it forms its chrysalis in the late spring, according to the National Audubon Society Field Guide to North American Insects and Spiders.

Those who have been following my other posts, especially this one, will notice that the eyed brown butterfly might fall into the moth category with a couple of the less reliable indicators like color and thicker body.

The caterpillar form of the eyed brown looks like it has horns at both ends, with those at the head being colored red with red lines extending to the eyes while the tail horns are green. The caterpillar is green with lighter green or yellowish stripes running along the length of its body. I don't have photos of the caterpillar or chrysalis (yet!), but you can see images (from bugguide.net) of the chrysalis here and the caterpillar here.

You'll note in the quick facts section below that the eyed brown lives in wet, boggy meadows and such. That does not generally describe my yard although there is one corner that borders an small open wetland area, and there is a large slow moving river in the valley below us (perhaps a mile away).

Quick facts about Lethe eurydice (or Satyrodes eurydice):
Life Cycle: the eyed brown lives a little over a year and has one generation per year. The caterpillar overwinters before forming a chrysalis and undergoing metamorphosis to become a butterfly in the late spring.
Diet: Sedge grasses as a caterpillar, nectar as a butterfly
Range: Bugguide.net says they range from Delaware to Colorado and north up into Canada (Nova Scotia on the east side and Eastern Alberta to the west).
IUCN Red List Status: unlisted

When Can it be Found Here: The eyed brown stays in place all year round, but may be spotty or regional in its range. It is in butterfly form from June to August.

Habitat: Wet marshes with sedges and cattails, bogs, open sedge meadows