10 December 2010

Mimicking Moths

We have definitely moved into the slow time of the year. It is dark when I drive to work in the morning, and once I get home from work I barely have time to get Bootypants through our trails before they are too dark to see. As a result, I have only taken photos on three days in November and three days in December. Because of this, I was clicking through photos from earlier in the year and came across this one that I thought was worthy of a post...

These are sphinx moths in the genus Hemaris. The best that this botanist can tell, these are Snowberry Clearwing Moths (Hemaris diffinis). I took this photograph in Lake County, Indiana on August 7, 2010. Snowberry Clearwing Moths, which are found throughout almost all of North America, are said to mimic bumblebees, and it is pretty easy to see why someone unfamiliar with these lepidopterans might get confused.

In looking through my old photos, I found the two below of moths in the genus Hemaris.

I feel pretty good about calling the moth in the photograph above another Snowberry Clearwing Moth. This individual seems to fit the description well, with black legs and a very clean margin between the thicker black portion and the clear portion of the forewings. I took this photograph back in May of 2005 in St. Joseph County, Indana.

Here is another old photograph, taken in July of 2006 in St. Joseph County, Indiana. From the descriptions I have seen, I would call this a Hummingbird Clearwing Moth (Hemaris thysbe). This species has lighter-colored legs and a thicker, more ragged-edged reddish-brown forewing margin. As the name implies, Hummingbird Clearwing Moths are often mistaken for hummingbirds, as they hover over flowers while probing for nectar. They are found in North America but seem to be absent from the southwestern part of the continent.


natureinquiries said...

Hi, Scott,
An easy way to distinguish snowberry and hummingbird clearwings, even when they are flying, is to look for a pair of narrow black stripes that extend down the front of the thorax from the head. One of these is just visible on the top insect of your pair in the first photo. As far as I know these are present on both genders.

Scott Namestnik said...

Thanks Carl. I assume that Snowberry Clearwing has the black stripe, and Hummingbird Clearwing doesn't?

Thanks for the help!

natureinquiries said...

Oh, yeah, that's right. Sorry about the ambiguous language.