"I Have A Little List": Connecting A Caterpillar

There are some species that I love to see, no matter how often I see them.  Monarch and swallowtail butterflies and caterpillars are on this list.  Toads and frogs and turtles of all sorts make it too.  In recent years I've added digger bees, digger wasps, and other native pollinators to my roll of favorites as well.  And I love sphinx moths, all sphinx moths, even the much maligned tomato hornworm.

Seriously, how can you not love moths that are easy to confuse with hummingbirds when they hover in front of a flower, feeding?

I've blogged about sphinx moths like this white-lined sphinx moth before.  This is no big surprise, as I do really enjoy seeing them and, occasionally, am even able to catch them on "film".  For example, in July 2009, I wrote about watching the white-lined sphinx moth feeding at my summer phlox; and last summer I wrote again about the white-lined sphinx moth, this time feeding on the larkspur, above, as well as about the snowberry clearwing feeding at the catmint blossoms.

Well, on Sunday night I made a new acquaintance:  a large hornworm feeding on my pink evening primrose (Oenothera speciosa) in the front garden.  Not being one to worry about caterpillars making a mess of my plants, instead of grabbing the caterpillar and squashing it, or (even worse) grabbing some insecticide and spraying it, I grabbed my camera and photographed it.

It was obviously a hornworm and, just as obviously, not a tomato or tobacco hornworm.  Because it was a hornworm, identification was not going to be too difficult:  I just went to my handy-dandy caterpillar guide (Caterpillars of Eastern North America, by David L. Wagner, Princeton University Press, 2005) and went to the Sphinx Moth family section, looking for a photograph to match the individual I was seeing outside.

And there wasn't one.  Damn.

So I started looking at the "Common Food Plants" section for evening primrose, which narrowed my choices down to 4 species of sphinx moths, one of which was white-lined sphinx moth (Hyles lineata), on page 275.  Hmmm.  Well, obviously I have the adults around here - and I'd never seen the caterpillar before.  Why hadn't I recognized the photo?

The first sentence in the Recognition section read, "Yellow and black or bright lime green with exceptionally variable patterning;...."  The italics was theirs.  The photograph was of the yellow and black morph - which is why I hadn't recognized it.  The other characteristics matched, as did the places of occurrence:  the head, thoracic shield and anal plate were all the same green color and speckled with minute dots, the thoracic legs were orange, and the horn was orange, plus the hornworm is commonly found in gardens and fields. 

When I checked with the images on Butterflies and Moths of North America,  http://www.butterfliesandmoths.org/, I found images of the green morph which looked almost identical to my mystery hornworm.

Mystery solved.

The first photograph was taken in the evening, 2 days ago, with a flash to supplement the lighting.  This more up-close-and-personal photo was taken this morning in natural light.  Don't you think it looks almost sated and ready to pupate?!

So now I'm waiting anxiously for my fat little hornworm to disappear and undergo its mysterious metamorphosis.  Then, for any white-lined sphinx moths I see feeding at my flowers this summer, I can imagine their "childhood" chowing down on my pink evening primroses and wonder if I've made his/her acquaintance before!